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Jan 2014

Video Wikipedia talk:WikiProject Mathematics/Archive2014

Wikipedia:Articles for deletion/Gilles Baroin

The new article Gilles Baroin is up for deletion. S?awomir Bia?y (talk) 14:01, 1 January 2014 (UTC)

Maps Wikipedia talk:WikiProject Mathematics/Archive2014

Epsilon zero

At the moment, wikipedia seems to be slightly confused about epsilon zero:

Epsilon zero and ?? (??) redirect to Epsilon numbers (mathematics).
Epsilon 0 and Epsilon naught and ?0 (?0) redirect to Epsilon number, a disambiguation page.
Epsilon nought and Epsilon sub zero redirect to Vacuum permittivity.

I think that vacuum permittivity is the most common meaning of epsilon zero (but then again, I am a physicist), and there is some discussion of this issue at Talk:Epsilon numbers (mathematics)#Redirect?, from a time before ?? (??) was moved to epsilon numbers (mathematics). I think that Epsilon zero and ?? andEpsilon 0 and Epsilon naught should be changed to redirect to Vacuum permittivity. That article already starts with a head note that says "For the ordinal number ?0, see epsilon numbers (mathematics)."

This change would mean that a number of existing links would have to be corrected. We could use the existing from epsilon zero (mathematics) to epsilon numbers (mathematics) when we fix the links.

Any suggestions/opinions? --Tobias Bergemann (talk) 10:34, 1 January 2014 (UTC)

The problem is that the short (two character) names are very difficult to find in a source file so that one can fix the link. If you look at the "What links here" for Epsilon numbers (mathematics), it is clear that all of the articles which are linking to those are, in fact, trying to link to the ordinal number and not to Vacuum permittivity. JRSpriggs (talk) 09:09, 2 January 2014 (UTC)

IMO, epsilon numbers (mathematics) must be renamed epsilon ordinals. Even for mathematician this is better, as ? and ?? appear commonly in other mathematical contexts, and a mathematician which reads "number" does not think first as "ordinal number". For the ?? and all the redirects that are synonymous, I would suggest to replace each of them by two redirects on the model ?? (ordinal) and ?? (physical constant). This will completely disambiguate at search level, at the price of editing the article linking to them. D.Lazard (talk) 11:35, 2 January 2014 (UTC)

Well, I've never heard of "epsilon ordinals", so I doubt this proposal meets COMMONNAME. But it might make sense to rename to epsilon number (set theory), and in that case surely ordinal numbers would be more likely to come readily to mind.

I note in passing that someone boldly changed the article from one on epsilon-naught specifically to one on the epsilon numbers in general, a proposal that had been discussed on the talk page without reaching resolution. That did annoy me slightly, but not enough to make a stink about it at the time, because the issue is fairly close on the merits. --Trovatore (talk) 16:15, 2 January 2014 (UTC)

I agree that "epsilon ordinal" is not a common terminology. The same is true for "epsilon number". As ordinal theory is a small part of set theory, I suggest epsilon (ordinal). D.Lazard (talk) 17:34, 2 January 2014 (UTC)

Honestly, I would prefer to move it back to something specific to ??, as the ?_? sequence is just not something that comes up that much, at least in my experience. I do agree that the permittivity of the vacuum is probably the primary topic for that search term, so something like ?? (set theory) or ?? (mathematical logic). --Trovatore (talk) 22:21, 2 January 2014 (UTC)

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Subtraction methods

In the article subtraction, I've borrowed some great images from Deutsch Wikipedia illustrating a lot of subtraction methods. However, I had trouble writing the summaries. Would anyone be interested in explaining how the Austrian method works or improving my explanation of the American method (or even changing the name "American method")?Brirush (talk) 02:15, 3 January 2014 (UTC)

There's no way to fit in Tom Lehrer's marvelous explanation of subtraction [1] in there is there? ;-) Dmcq (talk) 17:50, 5 January 2014 (UTC)

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Consistency in pluralization?

The articles parabola, hyperbola and formula all show that they can be pluralized with either an 's' or an 'e'. But within the article both are used. Should the article be made consistent on one?Naraht (talk)

The articlae (couldn't resist) should probably be internally consistent. YohanN7 (talk) 15:20, 5 January 2014 (UTC)

I have standardized hyperbola and parabola. Both articles mention (appropriately) the alternate forms, but now use only the English plural in the text. --JBL (talk) 16:04, 5 January 2014 (UTC)

I think in general Latin based plurals are disappearing in mathematics, and rightly so since math is hard enough without them. The exceptions seem to be words whose plurals would be awkward following the normal rules, 'matrices' instead of 'matrixes', 'axes' instead of 'axises'. Even this confuses a lot of people and students often talk about the 'identity matricee'. --RDBury (talk) 17:42, 5 January 2014 (UTC)

... and they all may be rulers of the Queen's Navee.... --Trovatore (talk) 23:12, 7 January 2014 (UTC)

I sometimes hear students use both "vertice" and "vertexes" in the same sentence :). Incidentally, I did not change formula because currently formulae is used more on that page than formulas and so I wanted to be sure there was general agreement on the English plural before making the switch. --JBL (talk) 15:17, 7 January 2014 (UTC)

I think someone changed it from formulas to formulae recently without asking, so they shouldn't mind if you change it back.Brirush (talk) 20:49, 7 January 2014 (UTC)

Thank you for pointing that out; I've now done the same to formula as to the others. --JBL (talk) 22:40, 7 January 2014 (UTC)

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Binary notation

When talking about plural digits, should we use 1s and 0s (ones or zeros), or 1's and 0's (which implies possession but seems to be more widely used)? P.S. Why do mathematicians confuse Halloween with Christmas? Because oct(31) = dec(25) --Gilderien Chat|List of good deeds 00:23, 25 December 2013 (UTC)

I'm sure that there will be differing opinions on this. Personally, I would use an apostrophe only if omitting it would lead to confusion. Probably in most contexts, 0s and 1s are fine without the apostrophe. Ebony Jackson (talk) 01:20, 25 December 2013 (UTC)

Apostrophes are also used in English to denote contraction, and I think of any numeral followed by "s" as a contraction. Thus "1980's", "0's", "1's", but "nineteen eighties", "zeros", "ones". S?awomir Bia?y (talk) 09:46, 25 December 2013 (UTC)

I thought that might be a reason to use 0's and 1's, but then 1980's is incorrect per the MOS and every other guide I've seen ever.--Gilderien Chat|List of good deeds 11:14, 25 December 2013 (UTC)

Yes, I agree; I would definitely favor 1980s over 1980's. Ebony Jackson (talk) 14:37, 25 December 2013 (UTC)

I suppose that's right. I'm not sure what the general rule is, then, but "0s" and "1s" definitely seems wrong to me. S?awomir Bia?y (talk) 15:40, 25 December 2013 (UTC)

Apostrophe#Use in forming certain plurals seems to say that neither with ' or without ' is really wrong, though I'd probably use the ' if pressed. To avoid controversy the real answer is spring for a few extra bytes and spell out "zeros and ones". --RDBury (talk) 03:23, 27 December 2013 (UTC)

"1980's", with an apostrophe, is the form used by the New York Times, but I think most others write "1980s". If you're abbreviating "greatest common divisor" as gcd and cumulative distribution function as cdf, the the apostrophe seems to serve a purpose. If you write those with capital letters then that's not needed: GCDs, CDFs. Michael Hardy (talk) 21:34, 27 December 2013 (UTC)

Actually, the New York Times too favors the usage without the apostrophe. Searching the newspaper at its website turns up far more references to "1980s" than to "1980's". Similarly, "0s and 1s" is more common than "0's and 1's". And in fact, their style guide as of November 14, 2011 says "do not use apostrophes for plurals of abbreviations without periods, or for plurals formed from figures: TVs, PCs, DVDs; 1990s, 747s, size 7s." Ebony Jackson (talk) 02:25, 28 December 2013 (UTC)

Their 2011 style guide must be a change in policy. Michael Hardy (talk) 00:08, 8 January 2014 (UTC)

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Question regarding well-defined vs. completely determined

There is an en wikipedia article on well-defined. However, I did not find one on "completely determined". I have found that these terms are sometimes not well understood by our educators, perhaps even by myself. For example, I might (very succinctly) say "For a right-angled triangle with acute angle x, we define sin(x) to be the ratio of the length of the side opposite x to the length of the hypotenuse. The number sin(x) is well-defined because a right-angled triangle is completely determined up to similarity by the size of the angle x and similarity guarentees that this ratio is a unique constant.". Please understand that I am trying to work in the two terms in one sentence (and not get caught up in the sentence itself). I believe this sentence illustrates the difference between the two terms.

I think it is important to give our educators (particularly elementary school educators who tend not to be mathematicians) a usable, well-defined term for them to be able to say something like "A rectangle is completely determined by its width and height, but a triangle is not.". Then we can consistently use this terminology.

If we think an article on "completely determined" might be useful, perhaps we could share some ideas on what it should contain.

Thank-you for reading. Lfahlberg (talk) 06:05, 7 January 2014 (UTC)

Per WP:NOUN, adjectives as article titles are generally discouraged. I'm actually not very happy that there is such an article as well-defined, and I certainly don't want to compound the problem. (What to do with the existing content at well-defined is a difficult problem, though.) --Trovatore (talk) 21:02, 7 January 2014 (UTC)

Not having thought very hard about it, it seems to me that the mathematical use of "completely determined" is decipherable by a person with no mathematical training, i.e., I think the jargony use of this phrase is an example of very transparent jargon. So for this reason I am inclined to say we don't need an article about it. (As I said, though, I haven't thought hard about this.)--JBL (talk) 14:30, 8 January 2014 (UTC)

I think this is an interesting point. In my mind, the phrase "completely determined" is a casual way of saying "there exists a bijection" (or sometimes something stronger, like an isomorphism or a diffeomorphism or whatever). The phrase "fully determined" would mean the same thing. So would many other statements like, "Knowing the height and width of a rectangle tells us which rectangle it is up to congruence." All of these could be made more explicit. I think the problem is that, while all these informal statements may be clear to the experienced reader, they may be opaque to the reader who doesn't already speak mathematics.

I don't think that there is a single good solution to this problem. Too-formal mathematics writing is clumsy, verbose, and indecipherable. Too-casual mathematics writing is vague, imprecise, and indecipherable. Every article needs to strike a balance, and the proper balance will depend on the article. Writing a page on "completely determined" might help some readers of some articles, but it will not help when the editor uses "fully determined" or "tells us" or some other casual phrase. In case there is a situation where "completely determined" is really confusing, it might help to either rewrite that portion of the article or link "completely determined" to bijection (or another appropriate article). Ozob (talk) 14:33, 8 January 2014 (UTC)

thanks to everyone who responded. i found each comment in this discussion most useful. Article specfic with perhaps for lower level sections the term "uniquely determined" might even be good and for higher level sections linking. Much appreciation. Lfahlberg (talk) 15:24, 8 January 2014 (UTC)

I would just point out, since you mentioned MathWorld, that MathWorld specifically is in many cases a great example of what not to do. MathWorld's definitions are in many cases idiosyncratic, bordering on neologistic, and no warning is given to the reader that the terminology being used may not be part of standard mathematical usage.

The problems of the well-defined article go well beyond its name being an adjective. The article abstracts a general concept from particular usages; an encyclopedia should not do that. I don't have a good solution to the problem at this time, but there really is a problem. We should not make it worse by repeating the mistake. --Trovatore (talk) 20:11, 8 January 2014 (UTC)

Apparently, my last response was unclear. I was summarizing that it seems the consensus (including my own) that no additional article should be created and that the term (uniquely, completely, fully, etc.) "determined" be used as needed in the writing of specific articles at the level of the reader of the material with a brief explanation or link (if necessary). I appreciated this discussion as it had clarified for me some aspects of the terminology "determined" with respect to different levels of mathematics and readers, e.g. I too think a pupil or elementary school teacher who is consulting this encyclopedia can understand the term "uniquely determined" with say a link to the keyword of congruence, similarity, etc. Lfahlberg (talk) 01:58, 9 January 2014 (UTC)

No, that's fine; I was responding more to your comments on the well-defined article.

BTW, even if there were a problem understanding "uniquely determined", it still wouldn't follow that we should write an article about it. Encyclopedia articles should be about something. They shouldn't be written just to document jargon. --Trovatore (talk) 02:03, 9 January 2014 (UTC)

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How to handle CMP index in cite template

Is a CMP ("Current Mathematical Publications"?) index a useful piece of information to retain, and if so, how should it be handled in the cite template? Thanks! Lesser Cartographies (talk) 03:53, 9 January 2014 (UTC)

TeX rendering on Firefox

It seems the newer versions of the Firefox browswer fail to display many of our pages correctly. For example:

\left({\frac {1}{2}}\sum _{k=1}^{\ell }\right)

versus

({\frac {1}{2}}\sum _{k=1}^{\ell })

The two displays above look quite different from each other on the chromium browser I'm typing this one, and that is as it should be, but they look identical to each other on recent versions of Firefox.

3+\cdots +3,\quad 3,\ldots ,3

versus

3+{\cdot }{\cdot }{\cdot }+3,\quad 3,{.}{.}{.},3

On the chromium browser, the last two displays above look quite different from each other in just the way they ought to. On Firefox, the \ldots look identical to the {.}{.}{.}. That should not happen. On Firefox, the \cdots and the {\cdot}{\cdot}{\cdot} do look somewhat different from each other, but the dots should be closer together in the latter version, and they're actually a bit farther apart in the latter version.

Should we:

(1) Alter our ways of doing things here (how?)?; or

(2) Complain to Firefox; or

(3) Something else?

Michael Hardy (talk) 00:23, 8 January 2014 (UTC)

That doesn't seem like a large problem to me, since the default for math is LaTeX PNGs. Firefox MathML bugs should definitely be reported, though I'm not sure anyone is actively maintaining FF's MathML support these days. Gutworth (talk) 00:49, 8 January 2014 (UTC)

My quite recent Firefox 21.0 displays these two pairs differently, which is supposedly correct: the first pair differs only by the size of parentheses (smaller in the second example); the second pair differs by spacing between dots (smaller in the second example). There must be something else/additional in your system which causes the identical rendering. No such user (talk) 13:46, 8 January 2014 (UTC)

FF 21.0 is recent? I have FF 26.0. I have the MathJax option set, so my view may not be typical. -- Arthur Rubin (talk) 15:16, 8 January 2014 (UTC)

You're right, I've lost the count since 15. However, I'm writing this from another computer using FF26, and rendering is much the same. And I have MathJax turned on, too. No such user (talk)

I have the latest version of Firefox (i.e. 26.0) and the differences you see in chromium are quite visible in my Firefox browser. JRSpriggs (talk) 07:09, 9 January 2014 (UTC)

AfC submission

Here's a new one for you. Thanks, FoCuSandLeArN (talk) 13:22, 7 January 2014 (UTC)

And another one. FoCuSandLeArN (talk) 20:37, 8 January 2014 (UTC)

Both articles (Integral of inverse functions and Approximate tangent space) are very good starts and ready for mainspace. I'll take the liberty of moving them, with the correct capitalization. M??c²???_?lk 07:34, 9 January 2014 (UTC)

Brouwer fixed-point theorem

This article is rated Start class. Surely it deserves a little bit better? YohanN7 (talk) 02:16, 9 January 2014 (UTC)

I've changed it to B class, although with that many references, it may be a good article candidate. I'll look at it more, but anyone can nominate it if it satisfies the requirements. -- Preceding unsigned comment added by Brirush (talk o contribs) 02:56, 9 January 2014 (UTC)

Thanks. YohanN7, please feel free to change the ratings of articles when you see them misrated like this. --David Eppstein (talk) 03:03, 9 January 2014 (UTC)

The GA folks will whine about there not being one reference per section/paragraph/sentence. S?awomir Bia?y (talk) 12:16, 9 January 2014 (UTC)

Poisson point process

Because several existing articles link to it, I've just created a new article titled Poisson point process. Our article titled Poisson process is only about one-dimensional Poisson processes. It could bear a lot of expansion. One could also rewrite the Poisson process article so that it covers this, but that would take a lot of rewriting. Michael Hardy (talk) 21:28, 9 January 2014 (UTC)

For the record, here are the currently existing non-template links to the article:

Poisson process ? (links)
Wikipedia talk:WikiProject Mathematics ? (links)
Talk:Shot noise ? (links)
Campbell's theorem (probability) ? (links)
Template:Stochastic processes ? (links)
Point process operation ? (links)
Nearest neighbour function ? (links)

If I'm not mistaken, soon every article that uses the "stochastic processes" template will be listed among these links, and there will be no way to tell which ones are non-template links (or have they changed that now?). Michael Hardy (talk) 21:34, 9 January 2014 (UTC)

Invitation to User Study

Would you be interested in participating in a user study? We are a team at University of Washington studying methods for finding collaborators within a Wikipedia community. We are looking for volunteers to evaluate a new visualization tool. All you need to do is to prepare for your laptop/desktop, web camera, and speaker for video communication with Google Hangout. We will provide you with a Amazon gift card in appreciation of your time and participation. For more information about this study, please visit our wiki page (http://meta.wikimedia.org/wiki/Research:Finding_a_Collaborator). If you would like to participate in our user study, please send me a message at Wkmaster (talk) 12:51, 10 January 2014 (UTC).

New functional analysis template added to many articles

A new user Mgkrupa has created a template for functional analysis topics and added the template to nearly 100 articles in short order; an example is Functional analysis itself in the footer of the article. I mostly ignore templates and don't know the policy on these, but some may want to check the work. --Mark viking (talk) 05:54, 10 January 2014 (UTC)

My policy is that if the template is conceivably useful to someone, then I ignore it completely if it's only a footer. I don't think the functional analysis footer is really all that bad, so I would be inclined to leave it in as it might make navigation useful for someone. (Things become a bit different with navboxes placed within the article itself: I am generally opposed to them, and they are impossible to ignore because of their placement.) S?awomir Bia?y (talk) 12:26, 10 January 2014 (UTC)

I wouldn't ignore all footers because of the risk of template creep, but this one seems well designed and meets the criteria for a good navbox. RockMagnetist (talk) 16:55, 10 January 2014 (UTC)

Cocycle

Cocycle is problematic on a number of levels. It has a footnote and a reference, elements which are not used on disambiguation pages, and the third line has no link, but appears to be an example or a formulation not found elsewhere in the encyclopedia. Is there a primary topic here? Is there a missing topic? bd2412 T 17:53, 12 January 2014 (UTC)

I agree, this article is not very good. It might be best to redirect to chain complex. Ozob (talk) 18:00, 12 January 2014 (UTC)

Topology good aeticle review

The reviewer for topology has asked for a second opinion for the use of a mathoverflow post as a reference. Does anyone have a suggestion for an alternate reference for the definition of geometric topology or an argument in support of this internet source?Brirush (talk) 19:28, 12 January 2014 (UTC)

How about [2] as a reference? Ozob (talk) 21:45, 12 January 2014 (UTC)

Quotition

We have a new article titled Quotition. Apparently the concept is current in the field of mathematics education. In the Oxford English Dictionary I find quotum and quotity, and quotient, all three of which seem related, but I don't find quotition. Michael Hardy (talk) 23:10, 14 January 2014 (UTC)

It seems to be a well-established concept. I added two books to the references - one from 1916 and one from 2006. There were plenty more. RockMagnetist (talk) 23:35, 14 January 2014 (UTC)

Problems with user: Incnis_Mrsi

I am respectfully requesting from this community that User:Incnis_Mrsi not be allowed to respond to me or pages I edit. I realize that this person has a long-standing membership in this community and I do not. This person responses towards me are neither professional nor respectful in any way and constitute personal attacks on me. As just recent examples, I tender the following responses to my conversations in the following talk pages: http://en.wikipedia.org/wiki/Talk:Linear_equation#no_citations http://en.wikipedia.org/wiki/User_talk:Lfahlberg#Constant_function

Today I edited the page: https://en.wikipedia.org/wiki/Constant_function. The response to my edits to this page by User:Incnis_Mrsi illustrates clearly that the intent of this person is not wikipedian nor - and more importantly - is it intended in the spirit of readability and usefulness to the user of wikipedia. I have worked on other pages here in such a spirit of community and collegiality that this attitude is simply not understandable nor do I think this is acceptable.

History of today's edit. In August 2013, I added to the talk page suggestions about these changes and no one objected to my notes. There were no citations in this article; none. I researched the topic, added appropriate definitions, images and 7 citations, correctly processed as per cite book and cite web as required by wikipedia. I would also note that I visited many other translation pages of this page before making changes to ensure that not only was my research correct, but also that it agreed with the globally accepted definition, explanation and use of the term "constant function".

Further, I specifically requested in the talk page that the community help with improving this page with respect to readability and usefulness.

I point out that I could not add the planetmath citation to the definition in section 2, namely http://planetmath.org/constantfunction since this page does not contain citation information as required by wikipedia. However, the definition stated in this section here is simply a formalized version of the definition given at the beginning and for which there are 3 proper citations. The examples and images given in this section are just that. Examples that directly apply the definition and images. They certainly do not constitute research.(Section 3 is not my work; it still has no citations, but I assumed in good-faith that it is correct and did not alter it in any way and apparently this IS acceptable to User:Incnis_Mrsi)

Thank-you for your consideration of my request. 19:45, 12 January 2014 (UTC) -- Preceding unsigned comment added by Lfahlberg (talk o contribs)

This isn't really a forum for complaints about specific Wikipedians unless it's a request for additional patrolling. Please read the Wikipedia:Dispute resolution guideline for help on how to resolve issues with other Wikipedians. --RDBury (talk) 17:43, 13 January 2014 (UTC)

I agree that the interaction of editors in Wikipedia could be better organized, but it is organized as it is. There is no firm authority, so, any editor can intervene if s/he sees a blatant violation of established editing norms. Even Incnis_Mrsi with his nasty habits and poor English, unless blocked. By the way, there are many things that I hate in Wikipedia. For example, I hate when someone wipes out a carefully prepared edit with a hypocritical and cynical summary. I experienced it from certain (third-party) user of this WikiProject not a long time ago, and now I am unsure that will restrain myself from saying him "fuck you" upon the next conflict. The difference is not about a "long-standing membership" here that some guys have whereas Mr. Lfahlberg hasn't. The difference is about guys who can edit articles in this (probably mismanaged) project, and those who begin to look for scapegoats. The Wikipedia community is hypocritical, unjust, libellous, and inherently illiberal. It is not aimed to defend anybody's rights or honour. Incnis Mrsi (talk) 19:30, 13 January 2014 (UTC)

I don't see anything actionable here. You Lfahlberg improved Constant function but made a few mistakes. Incnis Mrsi further improved it by correcting the mistakes. That's how Wikipedia works, improvement upon improvement. It's also how editors learn; as editors can dive into editing without any training or reading any instructions new editors often make mistakes. Being corrected by other editors is part of the learning process of being an editor, and for many editors never stops as they are always trying and learning new things.--JohnBlackburne^words_deeds 20:01, 13 January 2014 (UTC)

Oh, and if Incnis is a little bit rude on occasion - just be a little bit rude yourself in return. It will spice up a gloomy day in January. He'll take no offense. Nor should you. YohanN7 (talk) 19:40, 14 January 2014 (UTC)

I prompt Lfahlberg to cease various insinuations and start to learn WP:consensus-building procedures. All what I say is my opinion. It isn't an authoritative review of Lfahlberg's contributions. Aforementioned Lfahlberg's activity apparently is aimed to compel me to shut up. Will Lfahlberg's articles become better if the criticism became suppressed? Incnis Mrsi (talk) 16:11, 15 January 2014 (UTC)

Partial derivative : how to read and how to compute it ?

${\frac {\partial }{\partial {z}}}{\frac {\partial }{\partial {z}}}f_{c}^{p}(z_{0})$

I do not know what it means ? --Adam majewski (talk) 17:46, 12 January 2014 (UTC)

Differentiate twice with respect to z, keeping all other variables constant (which you have not indicated), then substitute z = z₀ into the result (after differentiation, not before). This does not look like a function of more than one variable, so only ordinary derivatives are needed. Have you read the partial derivative article? M??c²???_?lk 17:50, 12 January 2014 (UTC)

It is different then second order derivative ? I have looked at this article, but I'm not good at it.

Another example from wikibooks : ${\frac {\partial }{\partial {c}}}{\frac {\partial }{\partial {z}}}f_{c}^{p}(z_{0})$

Does it mean : mixed second order partial derivatives ? TIA --Adam majewski (talk) 18:57, 12 January 2014 (UTC)

This talk page is for discussing how to improve Wikipedia mathematics articles. It is not a math help site. For help with mathematics, try Wikipedia:Reference desk/Mathematics. Good luck. Mgnbar (talk) 19:18, 12 January 2014 (UTC)

I would say that

\left({\frac {d}{dz}}\,{\frac {d}{dz}}f\right)(z_{0}){\text{ and }}{\frac {d}{dz}}\,{\frac {d}{dz}}{\Big (}f(z_{0}){\Big )}

mean two different things, and the second one is zero. Michael Hardy (talk) 00:55, 13 January 2014 (UTC)

OK. There are so many things here. Maybe add these to the page about derivative ( for example section notation ]] ?

Can you also check the pages related with derivatives :

Mandelbrot_set#Interior_distance_estimation
Complex_quadratic_polynomial
from wikibooks

TIA --Adam majewski (talk) 17:23, 13 January 2014 (UTC)

You want these pages listed at Derivative? Are we to list every article that uses derivatives at Derivative? There would be too many. Derivatives can be found all over Wikipedia. Mgnbar (talk) 20:47, 14 January 2014 (UTC)

No , I ask experts for checking these pages . ( I have edited my previous post ) . --Adam majewski (talk) 15:34, 15 January 2014 (UTC)

What do you mean by "Maybe add these to the page about derivative"? What specifically do you want checked on these pages? Mandelbrot_set#Interior_distance_estimation and Complex_quadratic_polynomial seem fine. The wikibooks article should be discussed there, not here. M??c²???_?lk 19:56, 15 January 2014 (UTC)

AfC submission

Thank you for your help so far. This is another submission. FoCuSandLeArN (talk) 21:55, 16 January 2014 (UTC)

I installed the AfC script and accepted the article. -- Jitse Niesen (talk) 09:32, 17 January 2014 (UTC)

Thank you. Here's another one. FoCuSandLeArN (talk) 16:45, 17 January 2014 (UTC)

Wikipedia talk:Articles for creation/Chi-Squared Divergence

Dear mathematicians: This draft was never submitted for review at Afc. It appears to have references. Is this a notable topic? --Anne Delong (talk) 00:22, 20 January 2014 (UTC)

Hamilton Mathematics Institute

Is the article about the Hamilton Mathematics Institute in Dublin worth keeping? Someone suggested there is insufficient evidence of notability. Michael Hardy (talk) 17:53, 20 January 2014 (UTC)

List of algebras

Note: a stupid thread headline changed: this is not a discussion about the Help Desk. Incnis Mrsi (talk) 13:50, 20 January 2014 (UTC)

There's a discussion on the Help Desk about List of algebras. Please review List of algebras and if it's not needed, please address. Thanks. -- Jreferee (talk) 00:47, 20 January 2014 (UTC)

IMO, List of algebras must be merged into Algebra#Topics containing the word "algebra". By the way, in relation with this discussion an editor restored an old version of Algebra (disambiguation) in place of a redirect to Algebra, and has reverted twice my revert. IMO, this version of is a WP:DABCONCEPT article, and this disambiguation is better explained in Algebra. D.Lazard (talk) 10:57, 20 January 2014 (UTC)

To me it's very strange to emphasize the "not necessarily associative" algebras. Surely the "necessarily associative" algebras are a much more important distinguished subclass of these. S?awomir Bia?y (talk) 12:44, 20 January 2014 (UTC)

On the other hand, Heyting algebra is not even an algebra over a ring. I'd prefer to say something as "This is a list of various structures that match the most general definition of the term "algebra". Most of them are algebras over specified rings (or fields)" and add comments to list items, but I hesitate to save it. Incnis Mrsi (talk) 13:50, 20 January 2014 (UTC)

Maybe one should have an article titled List of algebras over a ring or something like that, and one or more separate lists of other sorts of objects called algebras. They would all exclude things in which the word "algebra" is a mass noun rather than a countable noun (i.e. senses in which it admits no plural form), but would list only _objects_ called algebras. Michael Hardy (talk) 17:57, 20 January 2014 (UTC)

Thoughts on this wikiproject

I have been trying to understand the actual problem. I will be specific first, generalize below.

Just for a moment, think back to when you were 14 years old and learning for the first time about functions and graphing. Let us think about something really simple, e.g. the y-intercept. (Excuse me while I head IM off at the pass before he sends me a note telling me that he has already warned me once about using a dash in math text and tell him that this term is standard in the us, uk and au.) Anyway, this term is defined in EVERY f-ing encyclopedia, textbook, online resource,... that exists (here I am actually thanking IM). So:

the concept of y-intercept should be (and is) acceptable as the subject for a wikipedia article
- even the "we do not need to cite anybody and our classification system is perfect for all mathematics resources" planetmath.org must agree that this is a legitimate topic (while of course relegating it to their joint category of "mathematics education & mathematics history".)
- this concept is CLEAN. it is limited to a rvf of rva f:R->R so planetmath.org is not interested in it and the article stands.
- Of course, there are no decent categories for it in the portal It is not an algebra. if one puts it into elementary functions, the poor pupil or teacher linking to that category would freak out. Math ed, that's it.

But, the article stands. No problem yet.

Now, being both maths and wiki people, we want to connect this article wrt to maths and the wiki. What is the very first use of y-intercept? Of course, it is a constant or linear function.

Big problem now. Now we have hit the HMP of planetmath.org and content on a page marked by planetmath is carefully monitored to be only their content.

You don't believe me? Read my note User_talk:David_Eppstein#Constant_function_edits who simply deleted an edit (that i had previously discussed in the talk 6 mos before and noone responded) stating unsourced (it was actually "sourced" planetmath -omg) and unhelpful (interesting new math proof term). Notice no response. (Concensus building - my ass.)

But many incoming editors (including obviously myself) don't know about the HMP. They have not yet connected the dots between the content of the portal and (in my case) a 10 year history attempting to get an adequate classification system for resources of usable content for teachers working with our children so that someone who needed the resource could actually find it. (~8-10 years ago i wrote merlot.org (who were then begging for OER interactive resources) and asked it they could possibly subdivide their tag category "math education" into 3 subcategories for elementary, middle and high school and received a wonderfully arrogant letter stating that the classification system of planetmath was perfect as is.)

Well, I finally connected the dots. And as I too was once young and only interested in "pure math" and bored with this kind of discussion, I understand that you probably don't care. But, this is a real problem.

Wikipedia math under this direction is not providing very many quality, usable resources for anything under 3rd year theoretical mathematics.

This is clear from the many blogs, online discussions, tweets, etc showing the frustration of the many varied people accessing our materials. Our kiddies (Including engineering students) and their teachers go to places like the Khan academy. (I am not disparaging this resource, but it often times does not provide mathematically correct, quality, consistent and connected information.)

At this time, I am not longer interested in continuing to challenge this attitude here. Been there, tried that - failed even here. I have more than paid my debts to our real educators (the ones in the crowded classroom squeezed by every possible side telling them that they are not real maths (this community), not real teachers (the educators with their philosophies and sample sets of n<=20) and statistically giving up teaching after 3 years.

I KNOW that there are members here that believe as I do - that our beginning and intermediate mathematics needs to be on a more-than-equal footing with higher maths (also that numerical mathematics needs to be properly integrated here). I appeal to you to change the attitude of this wikiproject and portal to reflect this.

As always, thanks for reading and thinking about this. I return to creating useful resources for the peons. Lfahlberg (talk) 07:28, 21 January 2014 (UTC)

Zeta(-1)

I'm not sure what's going on: has zeta(-1) been featured in the yellow media recently? Anyway, there is a discussion at Talk:Riemann zeta function#Zeta(-1) that would benefit from input of people who know the score. S?awomir Bia?y (talk) 20:08, 21 January 2014 (UTC)

It was started by [3], then picked up by various social media. Ozob (talk) 03:40, 22 January 2014 (UTC)

AfC submission

Another relevant submission. Regards, FoCuSandLeArN (talk) 14:36, 21 January 2014 (UTC)

I moved it to mainspace, helped by comments from Mark viking. -- Jitse Niesen (talk) 12:16, 22 January 2014 (UTC)

Feedback request: VisualEditor special character inserter

The developers are working on a character inserter for WP:VisualEditor. Their focus at the moment is on about 50 Wikipedias that have complex language requirements, like Welsh (but not like Chinese, which is a different kind of complexity). There is a special character inserter tool in VisualEditor now. They would like to know what you think about this tool, especially if you speak languages other than English--and mathematics isn't exactly what they had in mind (because an extensive TeX-based formula editor is the main way to deal with mathematics), but it does provide access to some mathematics symbols. So if you are interested in trying it out, please do so, and then let them know what you think of their choices for math symbols. The steps are easy:

If you haven't already opted-in, then opt-in to VisualEditor by going to Special:Preferences#mw-prefsection-betafeatures and choosing "VisualEditor". (While you're there, you might want to enable mathematics formulas, too.) Save your preferences.
Edit any article or your user page in VisualEditor. See the mw:Help:VisualEditor/User guide for information on how to use VisualEditor.

To let the developers know what you think, please leave them a message with your comments at the feedback thread on Mediawiki.org or here at the English Wikipedia at Wikipedia:VisualEditor/Feedback. It is really important that the developers hear from as many editors and as diverse as set of uses as possible. Thank you, Whatamidoing (WMF) (talk) 00:10, 23 January 2014 (UTC)

Cone

Must a cone have a circular cross-section? The article Cone initially says that it must, but other statements sprinkled throughout seem not to assume this, or seem unnecessarily vague if it is true. I raised this on the talk page a while ago, but no takers. Does anyone here have a view? 86.128.3.252 (talk) 18:40, 22 January 2014 (UTC)

The article asserted in the first sentence that the cross section is "typically" circular; this means "often" or "in the most common cases" and is perfectly consistent with the rest of the article. I've now substituted the phrase "frequently, but not necessarily," which hopefully is clearer (but I do not object if someone has a better phrasing). --JBL (talk) 19:37, 22 January 2014 (UTC)

The statement that you have changed refers to the base, not a general cross-section. I'm talking about the statement in the next paragraph where it says "such that there is a circular cross section". A cone can have a circular cross-section but be lopped off at an angle such that the base is not circular. The wording "a circular cross-section" seems to be designed to accommodate this case. My question is whether a cone has to have a circular cross-section, not whether the base has to be circular. 86.128.3.252 (talk) 20:14, 22 January 2014 (UTC)

The cross-sections parallel to the base are all necessarily of the same shape as the base. Now that I've read the full lead ( ;) ) I agree with you; I have removed the (uncited) statements that the cross-sections need to be circular. --JBL (talk) 20:34, 22 January 2014 (UTC)

Thanks, I should have mentioned this though, which says that a cone does have to have a circular cross-section. Is that source wrong? 86.128.3.252 (talk) 20:50, 22 January 2014 (UTC)

As with many things, there are different meanings of the same word; often, "cone" means "circular cone," but our article (as you note) is written about a more general class of objects, so the lead paragraph should match it. As you can probably tell, I have not carefully gone over the article or anything; perhaps the lead (and/or the rest of the article) should give more emphasis to the circular case, since this is (in geometry) the most common one, but the word "cone" is also widely used in the more general sense. --JBL (talk) 21:00, 22 January 2014 (UTC)

Right, the word may be used differently by different people, but our article should give the mathematically correct definition (and explain as necessary if it going to extend this to a kind of layman's definition). Normally I would assume that the MathWorld site was mathematically correct, but maybe not in this case ... 86.128.3.252 (talk) 21:16, 22 January 2014 (UTC)

(edit conflict) As far as I remember, a cone with a conic section as basis has always a circular cross-section. Nevertheless I do not remember of a simple proof of that fact. On the other hand, a cone with another curve as basis does not have any circular cross-section.

This article has another issue: depending on the context, "cone" may have various meanings, all mathematically correct, which should be disambiguated in the lead: a cone may be the solid or the surface delimited by the basis and the vertex. It may have a circular basis or have any curve as basis. It may be the surface generated by the rays sharing the same endpoint and cutting a curve. It may be the surface obtained by prolongating these rays into lines. It may also be the union of any set of rays (or lines) sharing a fixed endpoint (or point). All these notions are commonly called "cone" in mathematical texts, and only the context allows to disambiguate. Thus a WP:DABCONCEPT section seems to be needed here.D.Lazard (talk) 21:33, 22 January 2014 (UTC)

Note that the Cone (disambiguation) DAB page already exists and is accessible from a hatnote at the top of the Cone page. DABCONCEPT pages are useful when there is no one dominant usage of the title. But cone, as the geometric object, seems dominant to me. --Mark viking (talk) 22:14, 22 January 2014 (UTC)

+----------------------------------------------------------------------------------------------------+Perhaps it's just me, but I thought the base of a cone did not have to even be two dimensional, e.g. the code of a point is a line segment, the cone of a line segment is a triangle, the cone of an n-simplex is an (n+1)-simplex. Has anyone else seen that usage or did I make it up? --RDBury (talk) 03:35, 23 January 2014 (UTC)

What you describe sounds like a cone of a topological space, described at Cone (topology). --Mark viking (talk) 03:52, 23 January 2014 (UTC)

I've seen that usage. Michael Hardy (talk) 04:25, 23 January 2014 (UTC)

Thanks, the article is less of a muddle now that the statements requiring a circular cross-section have been removed. I spotted later in the article "The center of mass of a conic solid of uniform density lies one-quarter of the way from the center of the base to the vertex, on the straight line joining the two." This statement could do with tightening up with regard to cones whose bases have no obvious "center" -- either to exclude those cases if they are more complicated, or to refer to the "center of mass" of the base if that method always works. 81.159.106.14 (talk) 14:36, 23 January 2014 (UTC)

Distance from a point to a line and Perpendicular distance

These two articles have been around for a while and except for a few sentences in the lead of the second, their content is pretty much the same (or could easily be made so). It seems to me that a merge is in order. The question is which way should the merge go? I am not happy with either possibility, which is why I am bringing the subject up here. The distance from a point to a line article consists of several different proofs of the same 2-dimensional formula. This article was considered for deletion not too long ago, and several of you argued to keep it (but it doesn't look like anyone has seriously worked on it). I fixed a couple of proofs that had gotten garbled, but to improve the page I think we need to generalize the topic rather than provide more and better proofs of this simple formula. The Perpendicular distance article provides yet another proof of the 2-dimensional formula, and then states and proves a generalization to a formula for the distance between a point and a flat. This article has no references and no diagrams. Neither article contains a calculus based proof (or any other type of proof) that the shortest distance is along a perpendicular (but it is clearly assumed in each article). I think that at least the 2-dimensional proof would not be too far off the level of these articles. I also think that "perpendicular distance" is just a terrible title. My ideal solution would be to merge both articles into a new article, Distance from a point to a flat, but that title would not resonate well with the level of the readers of this article. I am looking for comments, suggestions, etc. Thanks. Bill Cherowitzo (talk) 18:28, 25 January 2014 (UTC)

I converted perpendicular distance into a set-index article listing four other articles (including the point-line distance one) on specific types of perpendicular distance. --David Eppstein (talk) 21:38, 25 January 2014 (UTC)

Thanks, I can work within that framework, but it still leaves open the issue of the weakness of the point-line distance article. There must be something we can do besides pile on proof after proof of the same result. Bill Cherowitzo (talk) 18:55, 26 January 2014 (UTC)

Pollock's conjecture(s)

I'm proposing a merge of the "tetrahedral" and "octahedral" conjectures into a single article. Any comments? (I only noticed this because one of them was added as a "See also" to Fermat polygonal number theorem, where I'm sure it should go.) -- Arthur Rubin (talk) 21:20, 27 January 2014 (UTC)

In general I favor separate articles for separate topics, but in this case the topics are so similar, and what little there is to be said about them also so similar, that I agree that a merge makes sense. --David Eppstein (talk) 21:26, 27 January 2014 (UTC)

Working copy at User:Arthur Rubin/Pollock's conjectures. The only difference is that the Mathworld article "Pollock's Conjecture" points only to the tetrahedral conjecture, while "Octahedral Number" has mentions the octahedral conjecture. -- Arthur Rubin (talk) 22:25, 28 January 2014 (UTC)

spelling of "l'Hopital's rule"

With this edit, a user has recently changed the text from explaining the difference as an "alternative spelling" to a "misspelling." This switches the tone from prescriptive to proscriptive, and so it deserves some attention. The previous version seems safer, if valid. Anyone know enough about French or math history to be able to verify it is an alternative spelling? Thanks Rschwieb (talk) 14:09, 28 January 2014 (UTC)

From Guillaume de l'Hôpital#Notes: "In the 17th and 18th centuries, the name was commonly spelled "l'Hospital", and he himself spelled his name that way. However, French spellings have been altered: the silent 's' has been removed and replaced with the circumflex over the preceding vowel. The former spelling is still used in English where there is no circumflex." Wikipedia is not a reliable source, but it does match my knowledge about French spelling, and makes sense. No such user (talk) 14:45, 28 January 2014 (UTC)

I agree. In French, the circumflex is (almost) always used for replacing a silent "s". The spelling "l'Hospital" is attested by the titles of two references of fr:Guillaume François Antoine, marquis de L'Hôpital and two external links of the same article. In fact, it appears that the correct spelling is "de l'Hospital", and that the other spellings are only common misspellings. Omitting the "de" is similar as talking about "Gaulle" instead of de Gaulle. However, "l'Hôpital rule" is a translation of the French "règle de l'Hôpital", and "règle de de l'Hôpital" is not so euphonic. D.Lazard (talk) 15:36, 28 January 2014 (UTC)

I don't think the spelling with a circumflex is an error. Some editions of his book appeared with this spelling. Tkuvho (talk) 15:49, 28 January 2014 (UTC)

Authors aren't known for misspelling their own names, so presumably this proves beyond any doubt that L'Hôpital's rule was in fact due to Bernoulli! S?awomir Bia?y (talk) 16:23, 28 January 2014 (UTC)

To Tkuvho: This depends if one accepts the modernization of the spelling for old people names. Thus "l'Hôpital" could be correct for the rule but not for the mathematician. Similarly, we have Vieta's formulas and François Viète (here, it is not modernization, but translation in another language). D.Lazard (talk) 16:50, 28 January 2014 (UTC)

Fontenelle's Éloge de M. le marquis de L'hopital (cited at the French page you linked) must have been one of the first to make the mistake of spelling it without an "s". Tkuvho (talk) 17:11, 28 January 2014 (UTC)

Thanks for all of the knowledgeable and prompt help. Rschwieb (talk) 15:26, 29 January 2014 (UTC)

AfC submission (Deep learning)

Wikipedia talk:Articles for creation/Deep learning. FoCuSandLeArN (talk) 13:41, 29 January 2014 (UTC)

There is already a deep learning article, apparently identical to the submission. Ozob (talk) 14:19, 29 January 2014 (UTC)

I (manually, as the script won't install until at least I close the browser) declined the submission, for that reason. The editor who requested the AfC submission replaced the mainspace article with his modified version. The question of whether this is a matter for WP:MATH is unclear, but I think this section should be considered closed. -- Arthur Rubin (talk) 16:51, 29 January 2014 (UTC)

Mathematics and art

Mathematics and art asserts as factual many discredited fringe theories e.g. about the use of the golden ratio in Greek and Egyptian aesthetics. I tried a modest {{dubious}} tag, only to have the edit reverted and a (bad) source for these claims added. Any suggestions for a process that can get this cleaned up? --David Eppstein (talk) 01:27, 30 January 2014 (UTC)

The dubious tag is understandable--that's a pretty ambiguous sentence. It looks like Chiswick tried to be helpful by adding two references, which you don't like. He probably thought he answered your call for references and (along with the refs in the, e.g., Parthenon section) removed the dubious tag. I've worked with him on a symmetry article and he seems a reasonable fellow--why not discuss it with him on the article's talk page? --Mark viking (talk) 01:53, 30 January 2014 (UTC)

There are more citations in Mathematics_and_art#Parthenon. The only statement questioning the use of the golden ration does not have a citation yet. RockMagnetist (talk) 03:17, 30 January 2014 (UTC)

The various subsections of Golden_ratio#Applications_and_observations contain a bunch of useful references for someone interested in rewriting the article more skeptically. --JBL (talk) 04:10, 30 January 2014 (UTC)

Topology of uniform convergence

Topology of uniform convergence until minutes ago redirected to Polar topology. Someone created a new article titled Topologies of Uniform Convergence, with all those capital letters and the plural, and I moved it to Topology of uniform convergence, deleting the redirect in the process. So now we have

Topology of uniform convergence, and
Polar topology.

So:

Should these get merged?

I'm not sure. The article Topology of uniform convergence deals with the case where the dual pair is (X, X') (i.e. with Y = X' in the polar topology article). So depending on what kind of presentation the reader is looking for, they might want one page but not the other.Mgkrupa (talk) 17:57, 30 January 2014 (UTC)

Also, thank you for your improvements on the article. Mgkrupa (talk) 18:14, 30 January 2014 (UTC)

What work should be done on the new article, which is longer than the old one? I am not comfortable with the intro paragraph, since the first sentence doesn't even mention the term topology of uniform convergence. Michael Hardy (talk) 04:51, 27 January 2014 (UTC)

Polar topology is a better title, since "topology of uniform convergence" usually means something else. S?awomir Bia?y (talk) 12:11, 27 January 2014 (UTC)

I think that Polar topology is not the better title since the article topology of uniform convergence describes topologies, such as on the spaces L(X, Y), that are NOT polar topologies. These topologies are all known as topologies of uniform convergence. Also, you said that ""topology of uniform convergence" usually means something else", what do you mean by that? Mgkrupa (talk) 15:08, 28 January 2014 (UTC)

See the disambiguation page uniform topology. S?awomir Bia?y (talk) 16:52, 28 January 2014 (UTC)

Also, you're right that these don't seem to be called polar topologies in the literature. The standard term seems to be just the

{\mathfrak {S}}

-topology (see Bourbaki, Espaces vectoriels topologiques, III.§3). S?awomir Bia?y (talk) 00:41, 29 January 2014 (UTC)

From the page Uniform topology I see that one of the links is for Polar topologies, which this article covers, and the other two are for uniform convergence of real-valued (which this article also covers) or metric space-valued functions (which it doesn't cover) and finally for uniform spaces. In terms of sending people to the most general notion of uniform convergence the article "Topology of uniform convergence" should then just be a link to uniform spaces, or a dis-ambiguity link (although I think that this would just confuse anyone who doesn't already know what uniform convergence means and is simply trying to learn the basic notions). What if we were to call this article "Topology of uniform convergence of vector-valued functions"? A long name but also the most accurate.Mgkrupa (talk) 17:45, 30 January 2014 (UTC)

Wikipedia talk:Articles for creation/Phan Sequence

Hello, mathematicians! Last chance to read this old Afc draft before it disappears for lack of reliable sources. --Anne Delong (talk) 15:11, 30 January 2014 (UTC)

There is no chance that reliable sources exist for this sequence. --JBL (talk) 16:49, 30 January 2014 (UTC)

Yes, I thought so. Thanks. --Anne Delong (talk) 21:41, 30 January 2014 (UTC)

Feb 2014

Intersection

This has recently been created, with the disambiguation page previously at this location moved to Intersection (disambiguation). The problem is I don't think the mathematical term is the primary topic: if anything the common usage of the word is when talking about road intersections (or listening to your sat-nav read them off to you), but probably being a common English word used in many ways and fields its best without a primary topic, as before.

At the same time the new article at Intersection doesn't seem to be on a distinct topic: it's mostly on geometric intersection, but includes some set theory and possibly other areas, leading to a very confusing introduction, some even more confusing links, and little else. The problem is the different mathematical uses have little in common, except for being different interpretations of the word in different fields. But that does not make for a good article topic.--JohnBlackburne^words_deeds 02:21, 30 January 2014 (UTC)

A road intersection is a 2-D intersection. Intersections in (Euclidean) geometry, algebraic geometry, and set theory derived from one common idea. What namely "does not make for a good article topic", this WP:CONCEPTDAB? Okay, make the intersection (geometry) article first, and then we'll discuss the merit of the "most general article". I think, most people here will agree that intersection (Euclidean geometry) shall not consider differentially-geometric aspects. Imagine one wants to know what is an intersection of a line and a quadric in a projective plane. These are generally curves, but the article on curves hardly considers the question of intersections. These are submanifolds, but the reader hasn't necessarily know this word. If s/he come to my stub, s/he will obtain some minimal idea how to approach the problem. If s/he come to the original dab, it will be a puzzle. Where to go: intersection (Euclidean geometry) (formerly "intersection point")? It misses the line at infinity. Intersection (set theory)? S/he will not learn anything new about the problem in question. Intersection theory? The reader will get a huge charge of general nonsense. Whereas for a reader who looks for something about Euclidean geometry there is little difference between "my article" and a conventional dab page.

"Even more confusing links" - which namely? "Little else" - yes, the house is just started. I think one should say about dimensions, as well as relationship between intersection of submanifolds and the orientation structure (what is expressed with the intersection number for dim_intersection = 0, but in more general case). Incnis Mrsi (talk) 08:59, 31 January 2014 (UTC)

I agree with Incnis Mrsi that the situation was confusing. However, IMO, his solution is not the best one. In fact, in mathematics, there is only one concept of intersection, the set theoretical one. I agree that, in incidence geometry, lines and planes are not considered as sets, but they are intuitively. And, in incidence geometry, one may consider the set of the points that are incident to a line; this allows to consider the intersection of two lines as a set theoretical intersection. Therefore I suggest the following

Rename intersection (set theory) as intersection (mathematics) (I have just noted that the latter is already a redirect to the former)
Add to Intersection (mathematics) a section "Intersection in geometry" with template {{main|Intersection (geometry)}}
Rename Intersection (Euclidean geometry) as Intersection (geometry) and add it a section about projective geometry (a motivation of projective geometry is to solve intersection problems)
Add to Intersection (geometry)#See also links to Intersection theory and Intersection number
Move back intersection (disambiguation) and replace the existing math. entries by a single link to intersection (mathematics)

D.Lazard (talk) 11:08, 31 January 2014 (UTC)

I do not agree with Daniel that "there is only one concept of intersection, the set-theoretical one". Set-theoretically there is no difference between an intersection proper and a tangential point (note another red link), but geometrically and algebraically there is. Also look at the picture please: set-theoretically there is a set of two points, geometrically there are simply two intersections, algebraic-geometrically there is a 0-manifold consisting of two components with different signs, provided the line, the circle, and the plane all are oriented. Why not explain it in one article, indeed? Also, what is now intersection (Euclidean geometry) is not a suitable candidate for converting to intersection (geometry). It is a typical enumerative article like the current revision of rotation (mathematics) (see talk:Rotation group for further development) and, unfortunately, many other Wikipedia articles, not mathematical only, that need to be conceptual instead of enumerative. Incnis Mrsi (talk) 15:07, 31 January 2014 (UTC)

I certainly edited Intersection (mathematics) (edit | talk | history | links | watch | logs) to redirect it to intersection (I even remember how I entered {{R from extra disambig}}). Apparently there was a browser glitch and the edit wasn't saved. BTW, the fr:Intersection (mathématiques) article is IMHO too poor to borrow something really usable from it. Incnis Mrsi (talk) 16:28, 31 January 2014 (UTC)

@Incnis Mrsi: When you write the the circle and the line of the picture have "two intersections" you are correct with respect to the non-mathematical meaning of "intersection" (road intersection), but you are not mathematically correct: the common mathematical terminology is that the circle and the line have two points of intersection, or two intersection points, or also that their intersection consists in two points. All these formulations are standard ways to talk about set intersections. Also it is clear that when the sets that are intersected have an extra structure, their intersection has also an extra structure. If I follow you argument, we should have an article for the intersection of vector spaces (the set intersection of two subspaces is a subspace), for ideals, and so on. Here, we have that the intersection of two algebraic varieties is an algebraic set, which, on your example, is not irreducible and has two components consisting of isolated points. Similarly a tangential point, aka tangent point, is a point of the (set) intersection that has a specific extra structure (the two curves or varieties or manifolds are tangent at that point). I do not see in your post any argument against merging Intersection and Intersection (set theory) into a single article called Intersection (mathematics). However, I see many reasons to use such a merger to improve both articles. D.Lazard (talk) 17:34, 31 January 2014 (UTC)

A good point about an additional structure. The only disagreement is about the precedence: I do not think the set theory should be qualified as the only formalism for intersection in mathematics. It is the standard one, certainly, but not an unique, and definitely not historically an original one (see below). Incnis Mrsi (talk) 19:28, 31 January 2014 (UTC)

(edit conflict)I agree with most of that: I think Intersection (geometry) is better than Intersection (Euclidean geometry); if that means adding some non-Euclidian geometry then do so, it's a good and natural extension of Euclidian geometry. I obviously agree with moving the DAB page back to Intersection. But I don't think it or the set theoretic use of intersection is the main mathematical use, I'd say that the geometric usage is as important. Looking at Intersection (Euclidean geometry) and Intersection (set theory) both are significant areas. So I'd change Intersection (mathematics) to redirect to the DAB page, i.e. Intersection. Apart from that any see-also links and {{main}} type links can be added as makes sense to clarify connections and help readers find articles.--JohnBlackburne^words_deeds 17:47, 31 January 2014 (UTC)

John, do not ignore my question, please. Which of my links are confusing? Of course my solution is not the best possible, but what namely did I do wrongly? Incnis Mrsi (talk) 19:28, 31 January 2014 (UTC)

I mentioned projective plane only as an easily accessible geometry that isn't Euclidean. There are numerous other alternatives to the Euclidean space: pseudo-Euclidean spaces, for example, or just the affine geometry where words "circle" and "perpendicular" are meaningless. Incnis Mrsi (talk) 22:41, 31 January 2014 (UTC)

The primary usage of the word "intersect" in my opinion is to cut, in the geometrical sense. This is consistent with the Latin origin of the term, and the current English vernacular (as in the intersection of two streets). The set theoretic meaning if the term was not even introduced until the 20th century (or possibly the late 19th century, the OED puts it at 1909). I'm not sure what this implies for an article on the topic. S?awomir Bia?y (talk) 17:40, 31 January 2014 (UTC)

A bit of support from an unexpected source. But I think we have two distinct (although related) questions: the fate of the new stub (as well as of intersection (mathematics) that I failed to redirect because of a glitch), and the primary topic of the title Intersection (edit | talk | history | links | watch | logs). I do not have a highly competent opinion about the latter and IMHO it should be discussed at talk:Intersection (disambiguation) because it can possibly escalate to an RfC or otherwise attract an attention of non-mathematical disambiguators. Incnis Mrsi (talk) 19:28, 31 January 2014 (UTC)

If an RfC's needed it could be created here; RfCs can be started anywhere, including user pages. But I don't think one's needed; we're not yet reached that point. As for the fate of the current Intersection there's no need for it: Intersection (Euclidean geometry) and Intersection (set theory) are two distinct topics. If there's need to connect them that can be done using appropriate text and links in both articles, and both should be linked from the disambiguation page. But they're not both sub-topics of a more general "mathematical intersection" topic.--JohnBlackburne^words_deeds 19:58, 31 January 2014 (UTC)

John, you catch from the discussion only things convenient to you, and dodge my question about your own claim the second time. Nobody tries to refute that "Intersection (Euclidean geometry)" and "Intersection (set theory)" are distinct. The discussion deals with following problems:

There is no article "intersection (geometry)" (virtually all participants).
The "new intersection" topic can be merged with "intersection (set theory)" to "intersection (mathematics)" (D.Lazard).
The "intersection (Euclidean geometry)" has an inappropriate content and structure to be simply expanded to "intersection (geometry)" (Incnis Mrsi).
"Intersection (geometry)" is historically the primary meaning, and the set-theoretical interpretation of intersection was popularized only in 20th century (S?awomir Bia?y).

You did not comment on any of these 4 points in a reasonable way, only reiterate some of things you said from the beginning: one should not bother to improve or save anything of it, [because] Incnis Mrsi wrote this crap. Incnis Mrsi (talk) 22:41, 31 January 2014 (UTC)

Since there is discussion over what "intersection" truly means, mathematically, I would like to point out that most intersections can be interpreted as fiber products in an appropriate category. This is true of sets, vector spaces, ideals, schemes, and so on. But the primary meaning of "intersection" is not "a kind of fiber product", and the primary article on intersections should not introduce it as such. Ozob (talk) 02:00, 1 February 2014 (UTC)

Just a hint: Please have a look to the German WIKI on intersection = Schnitt. --Ag2gaeh (talk) 10:57, 1 February 2014 (UTC)

The German is less directly analogous, since "Schnitt" is already part of the German vernacular and literally means "cut" (as a noun, at least, as in "ein Schnitt von Rindfleisch"--"a cut of beef"), whereas in English intersection is an old loan word from Latin that would have been used exclusively in a scientific setting before its adoption into the language. This is reflected in the relative rarity of the word "intersection" in modern day-to-day English (with the exception of referring to day-to-day things that are actually geometric intersections, like streets). A better comparison for de:Schnitt would be the English disambiguation page cut. S?awomir Bia?y (talk) 13:41, 1 February 2014 (UTC)

Sorry, I only had the mathematical part of the German page in mind and did not think about the "intersection" of a knife and a beef. --Ag2gaeh (talk) 10:45, 2 February 2014 (UTC)

Wikipedia talk:Articles for creation/Stability of Boolean networks

Dear math experts: Here's another old abandoned Afc submission that's about to be deleted. Is this a notable topic, and should the article be kept? --Anne Delong (talk) 18:10, 30 January 2014 (UTC)

Delete it. Ozob (talk) 02:02, 31 January 2014 (UTC)

The stability of a Boolean network is one of the most important properties of the dynamics of such a network. The article gives a poorly described criterion for stability in NK models with no significant intro or background. Our Boolean network article could use more material on dynamics, but this article is unfortunately not it. I would recommend passing on this one. --Mark viking (talk) 03:02, 31 January 2014 (UTC)

If the AfC is kept, then the material can be used to supplement the existing articles. Is this reason enough to keep it for a few months?

Sorry I wasn't clear--I don't think the prose is salvageable and refs are pretty easy to find on this topic, so I don't see the utility in saving any of it. Thanks, --Mark viking (talk) 20:04, 31 January 2014 (UTC)

Thanks for taking the time to check this out. --Anne Delong (talk) 03:55, 3 February 2014 (UTC)

"Octagonal"

AfC submission

Wikipedia talk:Articles for creation/K-trivial sets. Regards, FoCuSandLeArN (talk) 00:03, 4 February 2014 (UTC)

Also Wikipedia talk:Articles for creation/One-Shot Deviation Principle. Thank you, FoCuSandLeArN (talk) 01:08, 6 February 2014 (UTC)

Cyclic sieving

I've created a new, painfully stubby, article titled cyclic sieving. So work on it. Or, in other words, have fun. Michael Hardy (talk) 05:36, 6 February 2014 (UTC)

I think it would benefit greatly from one or two examples. JRSpriggs (talk) 06:19, 6 February 2014 (UTC)

So far only two articles link to it, so that's another thing to work on. Michael Hardy (talk) 20:07, 6 February 2014 (UTC)

EOM links

Spinningspark (talk · contribs · deleted contribs · logs · edit filter log · block user · block log) has been reverting the addition of EOM links en masse. I don't really have strong opinions about this, but I generally find the EOM to be a rather useful supplement to our own treatment of mathematical topics. At least some of the removed links are of a high quality (actually the first I noticed at Korn's inequality.) What does the project think about these edits? Should they be reverted? S?awomir Bia?y (talk) 16:31, 4 February 2014 (UTC)

I reverted them en masse because they had been inserted en masse. I am not particularly objecting to the site, I don't really know anything about the site one way or the other. However, the IP that has been inserting the links has been doing nothing else besides inserting them. That is spamming, regardless of the quality of the links. No justification was offered for inserting them in the edit summary, and I noted that many had been added as references without adding anything to the text. Since references are supposed to be there to support the text then that in itself looks spammy. As to their quality as external links, if editors think they are adding something that is not covered in the article then I'm fine with that, but it would be preferable that, if the material pointed to is suitable for Wikipedia, it should be added to Wikipedia and use the site as a ref instead of an EL. There are sometimes reasons material cannot be added to Wikipedia and an EL is justified on those grounds, but I'm not seeing anything here that fits in that category. SpinningSpark 16:59, 4 February 2014 (UTC)

To be sure, I don't question your reasons for removing the links, but I do think that in many cases these links are a valuable supplement to the article and that seems worth some consideration. S?awomir Bia?y (talk) 17:24, 4 February 2014 (UTC)

I'm fine with you just reverting me on the ones you think are useful. SpinningSpark 18:02, 4 February 2014 (UTC)

Sorry, I was the one adding all the links. My name is Camillo De Lellis and I am one of the editors of the Encyclopedia of Math, you can see my page there at User:Camillo.delellis. I noticed that several entries of the EoM are already regularly linked here at wikipedia, but the vast majority refers to entries which are rather old versions. Since I and other people have been renewing several of the pages there, I thought it was a good idea to check where they could be appropriately linked in wikipedia and I started going through mine ("En masse" might be subjective... note that from Christmas till now I anyway did not manage to link all the pages I renewed at EoM :-)). I spend a couple of hours per week with the entries at the EoM: this pretty much exhausts my alloted time for wikis and so I am not an active contributor of wikipedia. I was linking only pages which I believed appropriate and it seems to me that the pages I linked are more useful and appropriate than most of the EoM pages which are linked by other contributors (I am pretty choosy myself :-))). Some of the EoM pages do contain more material than wikipedia's corresponding pages, as for instance Function of bounded variation. Some, however, do not and I would consider EoM as a general reference work. In any case if what I was doing is considered spamming I stop right away. Sorry again, Camillo. -- Preceding unsigned comment added by 188.154.99.222 (talk) 09:01, 8 February 2014 (UTC)

I'm not a fan of addition/revert em masse either way. However disagree with an overly literal application of particular line in WP:EL here, that is only adding it if it really offers information not being contained in the article yet. I rather treat it (and to degree links to MathWorld, MacTuror and PlanetMath as well) as "standard" link as long as the EL is rather small and empty. In a way similar to linking the IMDB in movie related articles. The reason for that being twofold. For short article EOM, MathWorld and MacTutor can also be considered as "general" sources/sources outside of footnotes. In such that cases a placing under references might be more appropriate, but since they are links some editors place them under EL. The other reason is simply, that I consider it as beneficial to readers to offer links to alternative encyclopedic representations of math content.--Kmhkmh (talk) 15:39, 7 February 2014 (UTC)

Actually, WP:EL is much more stringent than you portray. It does not allow EL for information that is "not contained in the article yet". Rather, it is for information that would not be in the article if it were developed to FA standard: a much more stringent requirement. Also, I believe that the community consensus on ELs is that the default position is not to include them; that is, there should be a definite good reason before they are added rather than add them automatically. However, I agree that it is sensible to consider the state of the development of the article. Good ELs in a stub or short start class article can benefit both readers and editors seeking to develop it. Well developed articles on the other hand should be a lot more choosy about including ELs. SpinningSpark 00:35, 8 February 2014 (UTC)

Yes, I'm aware of that, it is so strict to the point, that it is almost nonsensical if applied literally (always). I'd also dispute the community consensus with regard to the literal reading somewhat (after following the page for years). It is more that it has been established via "tradition" and some editors prefer an overly strict formulation (as a sharp knife in dispute and block link farms and undesirable links) but in doubt relax it in practice. In fact somewhat similar to your approach. However looking at the discussion archives and behaviour of reasonable editors in practice, I don't really see a consensus. In fact imho this guideline only works because the strict literal reading of the line you refer too is largely ignored in practice and people similar follow the nutshell description or common sense.

Anyway having said all I more or less agree with you distinction between smaller and larger article. However even for a large article an external link with less information can be beneficial as it potentially conveys important or some information faster than a rather large article and it might be beneficial for readers to the simply see the "authoritative" encyclopedic take on the subject. That's why I don't mind to link the EOM for instance as long as external link section is not already filled with better or more suitable links. But that's just me.--Kmhkmh (talk) 08:41, 8 February 2014 (UTC)

I would prefer not to focus on the policy for external links in general but to focus the discussion on EOM. If the consensus is that addition of links to the EOM is helpful for readers of mathematics articles, so that the links improve the encyclopaedia, then we should Ignore All Rules that prevent us from making that improvement. Deltahedron (talk) 09:03, 8 February 2014 (UTC)

I agree, above I tried to make a case for WP:IAR and explain why many editors do not follow a literal reading of the policy, that is apply WP:IAR. Personally I'd consider an EOM-Link in most cases as beneficial.--Kmhkmh (talk) 14:36, 8 February 2014 (UTC)

More on cyclic sieving

Several people have now contributed to Cyclic sieving. References and examples were added. I have now added a precise definition in a section labeled Definition.

There are still only three other articles that link to this new article. Michael Hardy (talk) 19:01, 8 February 2014 (UTC)

Displayed equations are centered?

I recently edited Talk:Transitive relation, and found that displayed equations are centered. I use MathJax, so my view may not be typical, but there could be a problem here.

aRb\land bRc\rightarrow aRc

Yep, it's a problem here, also. -- Arthur Rubin (talk) 17:07, 7 February 2014 (UTC)

Looks like a problem with the code used to generate the MathJax code examining the code we have

I've created bug 61051http://bugzilla.wikimedia.org/show_bug.cgi?id= 61051 for this issue.--Salix alba (talk): 19:35, 7 February 2014 (UTC)

How should it look like? I had a long discussion about that with one of the MathJax developers. As a result, the goal is to introduce a Displaystyle feature --Physikerwelt (talk) 11:55, 8 February 2014 (UTC)

It should respect the style defined in the wikitext. If you look at the example above its

the maths tag is preceded by a : and WP:MARKUP#Indent text which says "Each colon at the start of a line causes the line to be indented by three more character positions." Editors will expect this rule to be applied, if the intention had been to center the equation then the {{center}} template or equivalent to be used.

There is a problem with the wikitext and you could say the above markup is a workaround for lack of proper maths support for display maths. --Salix alba (talk): 13:17, 8 February 2014 (UTC)

If you disable JavaScript in your browser, you can see that the code used to pass to MathJax is:

The centering decision is done within MathJax. To control the decision of MathJax the displaystyle attribute was proposed.

I think we should not start to change MathJax itself, because if we do so it will be hard to update to a new version. If there is a agreement to use the displaystyle attribute, and someone is willing to test that, we can merge that feature within a few days.--Physikerwelt (talk) 13:42, 8 February 2014 (UTC)

But things seem to have changed very recently. Possibly in the same update which caused the Texvc problem. Equations have been left aligned with MathJax until very recently, I've a screen shot from Oct 13 which shows this. --Salix alba (talk): 14:35, 8 February 2014 (UTC)

MathJax was updated from version 2.2 to version 2.3. Probably this caused the change. --Physikerwelt (talk) 15:28, 8 February 2014 (UTC)

I'm not sure where I'm supposed to report this, and moreover maybe it's just me, but an equation is still centered when "mathjax" is on.

1+2+3+\dots =-{1 \over 12}.

Interestingly, the problem can be fixed by adding ref:

1+2+3+\dots =-{1 \over 12}.

-- Taku (talk) 14:18, 9 February 2014 (UTC)

Anything you add outside the math tags, kills the centering. See Wikipedia:Village pump (technical)/Archive 136#Problems with math rendering. - DVdm (talk) 14:41, 9 February 2014 (UTC)

Wikipedia talk:Articles for creation/Ignatov's theorem

Here's another old Afc submission. It appears to have references. Is this a notable topic, and should the article be kept? --Anne Delong (talk) 18:32, 9 February 2014 (UTC)

I've rewritten the submission; it should be acceptable now. Ozob (talk) 19:31, 9 February 2014 (UTC)

With Ozob's nice rewrite, this article is ready for mainspace. --Mark viking (talk) 20:06, 9 February 2014 (UTC)

Okay, it's in mainspace now with one category and one incoming link. I put a Wikiproject Mathematics banner on the talk page, but I'm not sure if it's a stub or a start, so feel free to change that. Thanks! --Anne Delong (talk) 20:41, 9 February 2014 (UTC)

Numbering equations

Advice on whether and how to number equations is sought at User talk:Constant314#Numbering equations. JohnCD (talk) 23:37, 9 February 2014 (UTC)

AfC submission

Wikipedia talk:Articles for creation/Hessian equation. Regards, FoCuSandLeArN (talk) 19:39, 10 February 2014 (UTC)

Help needed with Correlation coefficient and Transition function

Correlation coefficient and Transition function are currently disambiguation pages, and have been among the most-linked disambiguation pages for the past four months. It would be great if we could either get the incoming links to these pages fixed, or arrange them into freestanding articles. This will likely require some expert attention. Cheers! bd2412 T 04:16, 9 February 2014 (UTC)

I think Correlation coefficient would be better moved to Correlation coefficient (disambiguation), after which make Correlation coefficient into a redirect to Pearson product-moment correlation coefficient; that I think matches common usage especially outside of mathematics where it is widely used.--JohnBlackburne^words_deeds 11:35, 9 February 2014 (UTC)

I don't know anything about the field, but if that is what people generally mean when they say "Correlation coefficient", that would be the right solution. bd2412 T 02:27, 11 February 2014 (UTC)

Problem with multiline equations

The Spherical trigonometry article has several bits of LaTeX that Failed to parse, for example the displayed equation in the Spherical trigonometry#Polar triangles section. My guess is that the alignat and align environments are not being handled. I went to the Wikimedia page Help:Displaying a formula and found that the align and alignat environments seem to be supported, but also generate a Failed to parse error on the page. A bug report at the wikimedia bugzilla suggests that these environments might be supported in MathJax, but not texvc. Is this a bug that others see? Thanks, --Mark viking (talk) 23:46, 6 February 2014 (UTC)

align should work with texvc. I just looked at a place I recently edited a formula with align, Triple product#Using geometric algebra, which I'm sure was working then, and it's now broken. The parser is complaining about 'aligned' not align, so is doing some sort of substitution, but I don't know if this is something it normally does. But I'm sure this was working two weeks ago: I was only editing that section, there's only one formula, and I would have used preview when editing it. I've tested MathJax before but haven't had it enabled for several months.--JohnBlackburne^words_deeds 00:01, 7 February 2014 (UTC)

I've asked about this issue at Wikipedia:Village pump (technical)/Archive 123#Math aligned environments failing to parse. Maybe an answer will magically appear there... Melchoir (talk) 02:08, 7 February 2014 (UTC)

Thanks John, for verifying the problem, and thanks Melchoir, for submitting to the technical village pump. --Mark viking (talk) 03:29, 7 February 2014 (UTC)

There is a similar problem at Noether's theorem?. Unfortunately, some people are trying to fix the problem by editing the source, not realizing that it is the software's interpretation of the source which is at fault. JRSpriggs (talk) 07:57, 7 February 2014 (UTC)

I ran into the problem as well, all multline formulas using \begin{align} ... \end{align} seem to be affected (see here Help:Displaying_a_formula, scroll through the page). However some special symbols seem to have a rendering issue as well (see de:Hilfe:TeX, scroll through the page)--Kmhkmh (talk) 11:38, 7 February 2014 (UTC)

As far as I can see, it seems to work again for me. -- Jitse Niesen (talk) 12:05, 7 February 2014 (UTC)

I'm having the same problem and unfortunately it's leading to people (mostly from anonymous IPs) removing important formatting. The issue with aligned formulas should have critical priority: it needs to be fixed as soon as possible. The servers were offline at some point yesterday, and I assume that this was related. S?awomir Bia?y (talk) 12:25, 7 February 2014 (UTC)

This remains broken for me. Seconding the urgency of this; the longer this takes, the more reverting we will have to do later. --Rhombus (talk) 13:07, 7 February 2014 (UTC)

I discovered that it has to do with the maths preferences; MathJax works fine (at least for me) while PNG gives problems. It is still not fixed; sorry for falsely suggesting it is working again. The relevant bug seems to be ~~bugzilla:60997~~ bugzilla:61012. -- Jitse Niesen (talk) 13:27, 7 February 2014 (UTC)

Problem still present. Isn't there a way to post a warning about this issue? Just to avoid people editing all sorts of math articles, escalating problems. This section in this talk page isn't all that easily found, even when looked for:) This is a serious issue after all. I think it should be posted somewhere central that it's known and is a server-side problem. --Loudandras (talk) 19:21, 7 February 2014 (UTC)

Personally, I think all articles in the List of mathematics articles should be semi protected, and an edit notice added saying that Wikipedia's implementation of LaTeX is broken, until it is fixed. I doubt that I would be able to convince WP:RFPP that this is an appropriate course of action, but even after one day I think this is going to require related changes patrolling of the List of mathematics articles by someone with tool server access (which afaik means Jitse). More than a day will be an unmitigated disaster. S?awomir Bia?y (talk) 19:30, 7 February 2014 (UTC)

I'm afraid a bunch of physics-related articles will be affected as well (Maxwell's equations for instance have already been 'fixed'). Not that removing the 'align' environments causes disaster, but these formulae would still look better in the original version. This could really get messy. --Loudandras (talk) 22:37, 7 February 2014 (UTC)

I've been finding the server very slow to respond today when I edit articles with mathematical equations in them, to the point where it sometimes times out without saving my changes (that is, it is a back end issue rather than a front end issue). Perhaps this is related? --David Eppstein (talk) 01:08, 8 February 2014 (UTC)

I was getting timeout/too many people accessing the page errors just looking at Noether's theorem and Help:Displaying a formula. Maybe the latter was unusually busy with the problems but not the former. And anyway WP handles pages becoming suddenly very busy for all sorts of reasons without problems usually. So it seems very likely it was the rendering problems on those pages, causing it somehow to timeout.--JohnBlackburne^words_deeds 04:02, 8 February 2014 (UTC)

Wikid77 (talk · contribs) and I have reverted each other a couple of times at Integral and Spherical trigonometry regarding this issue. Other editors may want to express an opinion. Ozob (talk) 06:08, 8 February 2014 (UTC)

As I expressed at the VP I back you completely on this: the articles aren't broken so no need to 'fix' them.--JohnBlackburne^words_deeds 06:29, 8 February 2014 (UTC)

Ultimately we need to do the right thing for the readers! That includes today's readers and future readers, after the software bug is fixed (and we don't know when that will happen).

It would be a reasonable compromise to "fix" high-traffic articles and list the edits on this talk page. Then, after the bug is fixed, it will be easy to revert the edits. Melchoir (talk) 07:06, 8 February 2014 (UTC)

Yes, but please wait a little bit if someone succeeds in turning amsmath support back on in texvc. Btw., the better replacement of align is {array}{rl}, {array}{rlrl} etc.--LutzL (talk) 11:48, 8 February 2014 (UTC)

I wrote a hotfix for that. It's waiting to be reviewed. After the problem should diaper. --Physikerwelt (talk) 11:48, 8 February 2014 (UTC)

Thank you! Ozob (talk) 15:30, 8 February 2014 (UTC)

Thanks for addressing this bug! Is there some way we can help write an automated test so that for instance breakages like this are caught in Jenkins before being deployed? --Mark viking (talk) 17:43, 8 February 2014 (UTC)

Sorry again for breaking the rendering. It was really only my fault. Prior to the change, the user input was checked (i.e. whitelisting to a secure subset of all possible TeX commands) for the PNG rendering mode only and not for MathJax and Source rendering modes. This caused a potentially security problem, i.e. given the fact that we wanted to render MathJax at the server side. I opened a bug in May 2013 and wrote and fixed it with the in the first attempt to release Math2.0 in October 2013. Since nobody wanted to review this, I broke down the change (that changed a lot of things (see list below) to several small commits. While breaking down the commits I made the mistake to put the required change for the texvc renderer to another commit than the security checking for MathJax. Since still nobody from WMF side wanted to do code review for that, I recruited new code reviewers for the math extension. In the end the change that does the security check for MathJax was merged and the changes to the PNG rendering mode were not merged. As a result the PNG rendering mode did the security checking twice. Unfortunately the output of the checked output is insecure, e.g. align is transformed to aligned which is not whitelisted. So that's the whole story.

For the testing, I think it would help if someone would vote for the bug concerning the test coverage. --Physikerwelt (talk) 21:49, 8 February 2014 (UTC)

As far as I can tell, "voting" on Bugzilla is ignored. Whatamidoing (WMF) (talk) 19:41, 10 February 2014 (UTC)

See also bugzilla:34490. Helder 13:32, 11 February 2014 (UTC)

The fix has been deployed now, and looking at a few pages it does seem fixed, though I had to purge one page to see it working.--JohnBlackburne^words_deeds 21:21, 8 February 2014 (UTC)

For those who don't know, you can purge the server cache with ?action=purge. Melchoir (talk) 21:26, 8 February 2014 (UTC)

You can also enable it in a menu in your gadgets preferences, 'Appearance' section, perhaps temporarily if you're checking and cleaning these up.--JohnBlackburne^words_deeds 21:55, 8 February 2014 (UTC)

Decoupling (mathematical analysis)

I think this article is a hoax. There is no source, the definition does not make sense, and the so-called "super-trowel", allegedly "one of the most used tools in the analysis of general equilibrium" fails to show up at ZMATH. Can anyone shed any light on it? Deltahedron (talk) 17:36, 11 February 2014 (UTC)

The speedy deletion tag was removed. I've prodded the article. Ozob (talk) 14:49, 12 February 2014 (UTC)

Not directly related, but there's obviously some editorial work needed in the articles decoupling and decoupling (disambiguation). --JBL (talk) 18:55, 11 February 2014 (UTC)

There's now discussion ongoing at Talk:Decoupling (disambiguation) and Talk:Decoupling (mathematical analysis). --JBL (talk) 17:15, 12 February 2014 (UTC)

Suborder into order?

Should the new article titled multiplicative suborder get merged into multiplicative order? Michael Hardy (talk) 20:34, 12 February 2014 (UTC)

It is difficult to imagine the article multiplicative suborder ever growing beyond a basic definition. --JBL (talk) 22:07, 12 February 2014 (UTC)

Summation

A properly sourced example of (Abel) summation by Euler was deleted by User:Slawekb here and here. Now that User:Incnis Mrsi joined the discussion, a tempered opinion would be welcome. Tkuvho (talk) 16:46, 10 February 2014 (UTC)

It should be noted that the material that User:Slawekb deleted was more of the -1/12 material that is so common. Perhaps the best solution would be to mention that Euler and others have done this summation, but that it is only useful or meaningful in very specialized circumstances, and then mention the fact that news reports in 2013 made too much of a big deal about this. Brirush (talk) 16:05, 12 February 2014 (UTC)

I have no problem mentioning this in the appropriate article 1+2+3+..., but in the main summation article it's undue weight and quite misleading without providing adequate context. In that article, it's rather a stretch to think that Ramanujan summation or zeta functional regularization or renormalization are in any way appropriate for a general article on the subject of summation. S?awomir Bia?y (talk) 18:59, 12 February 2014 (UTC)

Yes, User:DLazard pointed out that this article is only about finite summations anyways Brirush (talk) 19:05, 12 February 2014 (UTC).

As User:Melchoir pointed out at talk, it turns out that it is far from clear that Euler actually performed the 1+2+3+... summation, though of course 1-2+3-... is sourced. As far as the article Summation goes, I see no reason why it should not have a more advanced subsection dealing with infinite summations (ones that can be sourced, that is). Tkuvho (talk) 14:33, 13 February 2014 (UTC)

Summary style is appropriate in that case. The main article is series (mathematics). Also, please no coat racking to give divergent series more prominence than they deserve. S?awomir Bia?y (talk) 15:12, 13 February 2014 (UTC)

Not sure what "coat racking" is (coat rack does not help) but if you have a suggested wording please mention it at talk. Tkuvho (talk) 15:17, 13 February 2014 (UTC)

WP:COATRACK. S?awomir Bia?y (talk) 15:22, 13 February 2014 (UTC)

OK, thanks. I guess you've been around WP longer than me :-) Frankly I don't see why discussion of the paradoxes of infinite summation would obscure the topic of the summation page. Many mathematics pages have subsections containing far more advanced topics. Tkuvho (talk) 15:51, 13 February 2014 (UTC)

+----------------------------------------------------------------------------------------------------+ A more appropriate article for discussing such paradoxes would be the article on divergent series. This article is briefly summarized with appropriate weight in the series (mathematics) article. It's hard to see how emphasizing edge cases in the summation article would conform to WP:WEIGHT. S?awomir Bia?y (talk) 18:02, 13 February 2014 (UTC)

How to display math with the next release

Hi, I feel sorry about the problems with the current version of the Math extension.

My goal was to move from the current version to a completely new version of the Math-extension aka Math 2.0 in one step. Unfortunately, this does work with the code review system used at MediaWiki, since it was a lot code and nobody was willing to do a code review for that. So I started to integrate the changes via continuous integration. That means all features from the list below are going to be integrated step by step. I turned out that this is not a good idea as well.

Since the new features interact with each other, it happened that parts were merged whereas other parts are still waiting for the code review. For example in the case of the broken align environments the adjustments to the PNG mode were in another feature as the general security improvement that was merged. A hotfix for that is waiting to get merged to the Wikipedia live version https://gerrit.wikimedia.org/r/#/c/112057/ I really want to get feedback for the planned changes and asked over and again on the Mediawiki mailing list. But I did not get much feedback. So I'd be more than happy if someone would like to help testing the changes before they break things in production environments. See http://www.formulasearchengine.com/review for a guide that I wrote to attract people for that task.

The discussions above show that I might find someone in this portal... If not... sorry for the spamming.

Changes of Math 2.0

MathML support with SVG fallback (pending)
Distinction between inline and display-style
- http://math-test2.instance-proxy.wmflabs.org/wiki/Displaystyle (pending)
MathJax now available independent of the rendering mode (pending)
Debug functionality (pending)
independent of the file-system (pending)
backwards compatible, without dependencies to it (pending)
removes dependencies to math specific core functions
- getMathOptions() (merged)
- armourMath (pending)
Asynchronous generation of Math images (to be discussed)
upgrade to MathJax 2.3, use the unpacked version and remove unusued files (merged)
use MediaWiki's resource loader for Javascript files (merged)
improve the way MathJax is configured (merged)
make math fonts available as Web fonts for native MathML (pending)
The MathML/SVG output is used as a preview while MathJax is processing (pending)
new table (mathoid) enables quick migration from Math1.0 to Math 2.0 (no schema change for math table required) (pending)
SVG generation is done by using MathJax on the server-side. (pending)
Link to idividual equations
- ID feature request of Gabriel Wicke http://math-test2.instance-proxy.wmflabs.org/wiki/IDs#eq.20-sim

See a live demo http://math-test2.instance-proxy.wmflabs.org/wiki/Fourier_series.

It would help us to help you to be a little clearer about what you are trying to do (as an overview), why you are trying to do it, how you are doing it, what the results should look like, when it is proposed to happen and what you want our help with. For example, the paragraphs PS31,...,PS61 make no sense to me. Deltahedron (talk) 12:27, 8 February 2014 (UTC)

Oh, and it would be nice to know how it happened that the very first that people at this project, such as myself, heard about all this was when it broke mathematics rendering. Earlier involvement would have been helpful. Deltahedron (talk) 12:29, 8 February 2014 (UTC)

This isn't really my area expertise, but the bug makes me wonder whether there is any regression testing done before such software or configuration changes go live. I mean just a regression test against a single project side such as Help:Displaying_a_formula presumably would have revealed problems as the current one.--Kmhkmh (talk) 12:42, 8 February 2014 (UTC)

That's a good idea. I'll add the test (I had already implemented that before.). The hard thing will be to get a code review for the test. --Physikerwelt (talk) 13:09, 8 February 2014 (UTC)

I created a bug about the type of the tests. --Physikerwelt (talk) 14:09, 8 February 2014 (UTC)

When I started to work on the Math extension of MediaWiki (about one year ago) the connection to the page Wikipedia_talk:WikiProject_Mathematics mathematics was not obvious to me. I just found that page today, while googling for a bug report at bugzilla. And I really appreciate the feedback.

I'm basically looking for some people who want to discuss about how the display of math can be improved in the future and to test the implemented features. I feel sorry about the mistakes I made in the past, but I think it's better to look forward rather than to complain about the past. I'll update the Roadmap that I started more than a year ago. And come back to this project page again after completing this task. --Physikerwelt (talk) 13:05, 8 February 2014 (UTC)

Its good to see the move towards making MathJax as the default. I'm quite happy to do some testing, and contribute to BugZilla, but only as an end user and not at the git/code review level (just because I know very little about it). If test version is released on one of the test wikis I'll happily look at that.

That's great to hear. We have to find a way how this testing can be done. The current worflow is that after the code-review the change gets merged to all live versions of Wikipedia. Maybe we can set up a common test environment (like described in the http://www.formulasearchengine.com/review). To validate the functional correctness of the change before doing the formal code review. (Manny aspects of code review are related to whitespaces and typos in comments and commit messages.). I'll think about that.--Physikerwelt (talk) 15:27, 8 February 2014 (UTC)

I've tried using http://math-test2.instance-proxy.wmflabs.org/wiki/Fourier_series but I can't log in so can only see it in SVG. I tried following the the log in instructions on the main page and 'There is no user by the name "MathJaX".'.--Salix alba (talk): 13:49, 8 February 2014 (UTC)

Thank you. You found the first error. The unser name is MathJax. I corrected that on the main page. --Physikerwelt (talk) 15:27, 8 February 2014 (UTC)

Cool, I can login now. The first obvious error is failing to parse some equations with 'Entity nbsp' not defined. Seem spaces inside \text( and ) get translated to somewhere along the line.

I'm not really sure how things are different to what is on en.--Salix alba (talk): 16:19, 8 February 2014 (UTC)

I tried without logging in and search doesn't work: I got An error has occurred while searching: Error fetching URL: couldn't connect to host

At my first random page, Lundquist_number the subscripts and superscripts don't work: they just give spaces. Deltahedron (talk) 17:10, 8 February 2014 (UTC)

The same problem with sub/superscripts when I log in as MathJax. Typing into the box provokes a series of errors in the console at the foot of the page but the search then works. Rendering of letters in italic (text) and roman (display) seems inconsistent. Deltahedron (talk) 07:56, 9 February 2014 (UTC)

By the way, it would help us to help you if we knew where you want this sort of problem reported -- is there a centralised location for collecting comments and questions -- surely this subsection isn't it? Is there a list of known problems that don't need to be reported again? Is there a list of changes or proposed changes that you particularly want tested? Is there a list of things you've changed but which you're quite sure can't possibly affect the user experience? Is there a roadmap for future development and a schedule of proposed work? Where is all this information collated and made visible to other editors? Deltahedron (talk) 09:41, 9 February 2014 (UTC)

@Deltahedron: I'm open for proposal how to organize feedback and mange the todos. Yesterday I went throguh bugzilla there were 85 bug reports. Now there are 71. (Some of them were really old and already fixed.) I updated the bug List at the Roadmap. From what I see there are two option for the organization of the project. Either to user that roadmap page and maybe some subpages or to use Bugzilla. I saw some green and red buttons on Wikipedia buttons where user can give feedback. Maybe they could be useful to get a quick overview, which features are most wanted. I'll clean the math-2 test server and remove the experimental features that are connected to my PhD thesis about Formulasearch and are not supposed to be used at Wikipedia in the short term. PS: My prototype use case, to find the Jensen's_inequality by searching for

\langle {\frac {1}{x}}\rangle \geq {\frac {1}{\langle x\rangle }}

, is not reachable in the near feature, due to a lack of semantic information in formulae. --Physikerwelt (talk) 10:18, 9 February 2014 (UTC)

Perhaps it would help to create a page www.mediawiki.org/wiki/Extension:Math/Feedback and advertising it here, be appropriate for comments and discussion on such things as the roadmap at www.mediawiki.org/wiki/Extension:Math/Roadmap and experiments and experiences at math-test2.instance-proxy.wmflabs.org. Then advertise it widely, with a permanent link at places like WP:WPM and with a mention in the current debates at Wikipedia:Village pump (technical). Deltahedron (talk) 11:42, 9 February 2014 (UTC)

@Deltahedron: Great idea. First I'll start with the automated tests. If someone could start to create such a page in the meantime that would be great. Furthermore, there are a lot of open bugs left. I think there are still some missing in the overview page. In the end we have to come up with an orderd list of features that we break down into planned releases in the end. --Physikerwelt (talk) 12:21, 9 February 2014 (UTC)

Is there a general agreement that the roadmap would be a good central point for discussions. Just because it's somehow pointless to set up a site if nobody comments... Like it sometimes happens at the mailing lists http://wikimedia.7.x6.nabble.com/template/NamlServlet.jtp?macro=user_nodes&user=365222 --Physikerwelt (talk) 12:42, 10 February 2014 (UTC)

Physikerwelt, I just want to thank you for your work. I tried to do some work many years ago and I did not get much feedback from the developers then (it was all run less professionally then). Don't feel too bad about the align issue and don't give up. -- Jitse Niesen (talk) 17:14, 8 February 2014 (UTC)

I noticed the article Fermi-Pasta-Ulam problem has a messed up display, and when I looked at Help:Displaying a formula to see how to fix it, that is messed up too--I came here for help and see that others here have noticed the same thing. Is it possible to revert to the old version of the software for now, and debug the new code on a test server before deploying it to production? I believe the WMF does have some test servers available for this type of thing. Thanks. 70.36.142.114 (talk) 17:19, 8 February 2014 (UTC)

There is a fix for the bug that waits for review. I try to find someone who has the power to merge it.--Physikerwelt (talk) 18:23, 8 February 2014 (UTC)

@Physikerwelt: Is the following a valid summary of the current situation? As a security measure, and to get the same output regardless of method, you broke out the translation/normalization/macro-expansion part of texvc as texvccheck. The normalized output of texvccheck is then used as input for all the other output methods. This should have worked transparently except for the old misguided decision to name the multiline sub-environment "align" instead of "aligned". Misguided since if one considers the "math" tags as forming an outer math environment, everything inside "math" tags should be a sub-environment. And so the translation of texvccheck produces output "aligned" for input "align", which is correct for latex and mathjax, but not recognized by another texvc run (idempotence) to generate the png images, since texvc does not recognize "aligned" or "alignedat" as input environments. Is your fix making texvc accept them?--LutzL (talk) 18:44, 8 February 2014 (UTC)--Edit--LutzL (talk) 19:14, 8 February 2014 (UTC)

No to the last question, I see from the patch diffs that the second texvc run is given the original, untransformed tex input.--LutzL (talk) 19:20, 8 February 2014 (UTC)

That's correct. texvccheck is a subset of texvc... originally I wanted to call it texvc-light... but this name was not accepted. To explain it in a mathematical way. We call

s

the securtity check and

l

the latex conversion that texvccheck for input

x

mans

s(x)

. Appling texvc to

x

means

l(s(x))

. The bug was that both, texvccheck and texvc were applied to

x

and

l(s^{2}(x))

was displayed.

s

is not idempotent which means that

\exists x:s^{2}(x)\neq s(x)

. For example let's assumme that

x_{1}

contains a an align command than

s(x_{1})\neq s(s(x_{1}))

since align is transformed to aligned which is not whitelisted. --Physikerwelt (talk) 22:14, 8 February 2014 (UTC)

The fix seems to have been deployed; I'm not seeing any problems. Ozob (talk) 22:34, 8 February 2014 (UTC)

I agree, the problems I was seeing with the align and alignat environments look to be fixed. Thanks again, Physikerwelt for getting on this and and getting the hotfix in! --Mark viking (talk) 23:06, 8 February 2014 (UTC)

Fermi-Pasta-Ulam problem works ok now, but Integral of the secant function shows a lot of messed up equations. 70.36.142.114 (talk) 05:47, 13 February 2014 (UTC)

Performance problems

Are the current performance problems also due to the upgrade? In several wikipedias previewing or editing articles with formulas takes very long at the moment. Articles with many formulas (such as List of mathematical symbols) even get a "504 Gateway Time-out" when you just try to preview them. Best wishes, --Quartl (talk) 06:32, 9 February 2014 (UTC)

Yes. I thought this was caused by the broken rasteriser but it still seems very slow despite that being fixed. I just tried loading Seven-dimensional cross product then unnecessarily purging it to force it to redo everything. Here (from the page source) is the timing information on the purge:

  NewPP limit report  Parsed by mw1173  CPU time usage: 1.452 seconds  Real time usage: 26.816 seconds  Preprocessor visited node count: 3564/1000000  Preprocessor generated node count: 10682/1500000  Post-expand include size: 50621/2048000 bytes  Template argument size: 3857/2048000 bytes  Highest expansion depth: 11/40  Expensive parser function count: 1/500  Lua time usage: 0.091s  Lua memory usage: 2.49 MB

26.8 seconds. And is isn't especially long or template heavy. The one thing it does have is a high density of formulae.--JohnBlackburne^words_deeds 06:45, 9 February 2014 (UTC)

I tried looking at List of mathematical symbols and that took a lot longer, though it did eventually load.

  NewPP limit report  Parsed by mw1079  CPU time usage: 13.505 seconds  Real time usage: 308.243 seconds  Preprocessor visited node count: 11927/1000000  Preprocessor generated node count: 37075/1500000  Post-expand include size: 217037/2048000 bytes  Template argument size: 90026/2048000 bytes  Highest expansion depth: 15/40  Expensive parser function count: 3/500  Lua time usage: 0.084s  Lua memory usage: 2.76 MB

This was only the first time accessing it. Reloading the page took a second. Obviously purging or editing would force it to redraw and so would take a similarly long time.--JohnBlackburne^words_deeds 07:05, 9 February 2014 (UTC)

I'm quite sure that this issue is connected to the new security feature. I followed the guideline, "you can not trust database entries" and check the user input text every time it's send to the rendering engine, even before the database lookup checks if the entry is already in the database. In local experiments this had almost no impact on the performance. Obviously the situation is different in production. I proposed to opt-out this new security feature via $wgMathDisableTexFilter = true on the bug report.--Physikerwelt (talk) 09:50, 9 February 2014 (UTC)

Out of interest, in what sense was this a "security feature"? Is there a specific security issue here or is this just belt-and-braces? Deltahedron (talk) 10:03, 9 February 2014 (UTC)

No there is no known urgend concrete threat, that can be caused by entering potentially dangerous input between <math> and </math>. But without this feature the possible input depends on the rendering mode, and we rely on the build in security of renderer i.e. MathJax or LaTeXML. Furthermore texvccheck provides a well defined set of allowed input, which could be discussed and modified in the future. However, I think that the drawbacks of slower editing are not compensated by the benefits of the well-defined and secure input independent of the rendering engine. --Physikerwelt (talk) 10:39, 9 February 2014 (UTC)

Any news on this? I just timed Seven-dimensional cross product and the article still takes close to 30 seconds to preview or purge. Best wishes, --Quartl (talk) 19:40, 12 February 2014 (UTC)

FIXED. See: #Performance of cache fixed 15 Feb 2014. -Wikid77 08:39, 15 February 2014 (UTC)

Is this really fixed? I'm seeing long loading times for math pages again, simply viewing a page. E.g. Clifford algebra gives me the following:

  NewPP limit report  Parsed by mw1076  CPU time usage: 1.236 seconds  Real time usage: 26.291 seconds  [...]

Exterior algebra gives.

  NewPP limit report  Parsed by mw1046  CPU time usage: 1.548 seconds  Real time usage: 30.305 seconds  [...]

And this is not previewing or purging, just viewing (though subsequent views are fine). The pages were last edited on the 7th and 8th of this month so were presumably viewed and cached then, and even if they required recaching since the patch they're viewed over 100 times a day each on average. How are they still slow four days later?

Performance of cache fixed 15 Feb 2014

By 00:02 15 February 2014, fix deployed (https://gerrit.wikimedia.org/r/113481) by User:Aaron_Schulz as update so math-tags run faster, than during 8-14 Feb 2014. I have confirmed the math-tag cache speed as double (2.4x), similar now to Simple WP, so new equations edit-preview 2.4x faster than before (124 math-tags in 38 seconds, formerly 92 sec.) and then will re-display from cache within 3 seconds. -Wikid77 08:39, 15 February 2014 (UTC)

List of mathematical symbols as TeX codes

There is a new article called List of mathematical symbols as TeX codes. I haev commented at Talk:List of mathematical symbols as TeX codes and put a factual-accuracy-dispute tag at the top of the article. So some work is needed. Michael Hardy (talk) 17:33, 14 February 2014 (UTC)

Why not include TeX commands (and for that matter HTML codes and Unicode code points) as separate columns in List of mathematical symbols (as I did in de:Liste mathematischer Symbole)? Best wishes, --Quartl (talk) 18:13, 14 February 2014 (UTC)

My thoughts as well. There seems to be no clear reason for having what is just a copy paste of List of mathematical symbols with nowiki tags thrown in. S?awomir Bia?y (talk) 18:57, 14 February 2014 (UTC)

I have nominated the page for speedy deletion as an A10, "recently created article that duplicates an existing topic". Ozob (talk) 20:35, 16 February 2014 (UTC)

user Wachipichay

I noticed that the user Wachipichay is making many edits to mathematics pages. It seems the purpose of all edits is to include references to a mathematician called István Mez?. As far as I can tell, these are typically very recent minor results that have no place in an encyclopedia. Perhaps someone who reads this can have a look at his edits and clean up as needed. I apologize if this is the wrong forum, I am not active on Wikipedia and have no idea how these things work. 129.16.126.117 (talk) 08:43, 18 February 2014 (UTC)

At least, not all edits; Gamma function#Raabe's formula is not. But most of them are. Boris Tsirelson (talk) 09:36, 18 February 2014 (UTC)

FYI: Wachipichay (talk · contribs · deleted contribs · logs · edit filter log · block user · block log) S?awomir Bia?y (talk) 12:50, 18 February 2014 (UTC)

Euler's identity?

I think this is a prime example of a mathematics page which needs to communicate with a general readership [4]. I have posted some strictly editorial concerns on the talk page which I think deserve some response. Thank you in advance, 109.157.83.88 (talk) 11:46, 13 February 2014 (UTC) [previously 109.158.185.136 and 81.147.165.192]

I have tried to address (in this edit) some of the issues I've encountered as a layperson coming to this page. The more general disambiguation problem in the page header (and at List of things named after Leonhard Euler) imo remains. While fully recognizing that we're all volunteers and that nobody is obliged to make any particular contribution I find it hard not to express some disappointment that my appeals for feedback appear not to have elicited any response (so far) either here or on the article talk page. 86.173.146.3 (talk) 14:14, 18 February 2014 (UTC)

Probably you have gotten no response (until today) for the following reasons:

(1) The number of people confused by the issue troubling you is well approximated by 0.

(2) The source of your confusion is your not very good source, which draws distinctions that mathematicians do not (either in the formal or informal setting).

You can see my more detailed comments on the talk page of the article in question. --JBL (talk) 20:10, 18 February 2014 (UTC)

(1) Your forcefully worded statement "The number of people confused by the issue troubling you is well approximated by 0" implies that the present Wikipedia editor does not belong to the set of people? (I do request you to be civil to your fellow gf Wikipedian.)

(2) I will certainly reply on the article talk page. As a general principle I think it is courteous in such circumstances to source your assertions. (My understanding is that Wikipedia does not contemplate argument from authority.)
86.173.146.3 (talk) 21:25, 18 February 2014 (UTC)

Eigenvalues and eigenvectors - Illustration

What am I missing? The rationale for depicting vectors as "line segments" floating on a stretchy background rather than as unique elements of a vector space is eluding me, including that these are "an elementary concept in vector spaces" not even needing to be mentioned in that article, and intuition can be relied upon for underlying concepts in WP. --Quondum 02:41, 20 February 2014 (UTC)

Popular pages tool update

As of January, the popular pages tool has moved from the Toolserver to Wikimedia Tool Labs. The code has changed significantly from the Toolserver version, but users should notice few differences. Please take a moment to look over your project's list for any anomalies, such as pages that you expect to see that are missing or pages that seem to have more views than expected. Note that unlike other tools, this tool aggregates all views from redirects, which means it will typically have higher numbers. (For January 2014 specifically, 35 hours of data is missing from the WMF data, which was approximated from other dates. For most articles, this should yield a more accurate number. However, a few articles, like ones featured on the Main Page, may be off).

Web tools, to replace the ones at tools:~alexz/pop, will become available over the next few weeks at toollabs:popularpages. All of the historical data (back to July 2009 for some projects) has been copied over. The tool to view historical data is currently partially available (assessment data and a few projects may not be available at the moment). The tool to add new projects to the bot's list is also available now (editing the configuration of current projects coming soon). Unlike the previous tool, all changes will be effective immediately. OAuth is used to authenticate users, allowing only regular users to make changes to prevent abuse. A visible history of configuration additions and changes is coming soon. Once tools become fully available, their toolserver versions will redirect to Labs.

If you have any questions, want to report any bugs, or there are any features you would like to see that aren't currently available on the Toolserver tools, see the updated FAQ or contact me on my talk page. Mr.Z-bot (talk) (for Mr.Z-man) 05:15, 23 February 2014 (UTC)

List of unsolved problems in Cryptography

Global analysis?

We have no article titled global analysis. Michael Hardy (talk) 20:08, 23 February 2014 (UTC)

That was my thought exactly too. I don't feel qualified to create the article myself, but this is such a terrible oversight. -- Taku (talk) 20:22, 23 February 2014 (UTC)

Is this the only omission from the top-level MSC categories, as listed here? Deltahedron (talk) 20:47, 23 February 2014 (UTC)

Judging from Mathematics Subject Classification, the two red links are Expansion (approximation theory) and Mechanics of deformable solids. I think we have the latter covered in articles such as Deformation (mechanics) and Elasticity (physics). I don't know about the former. We have articles like Taylor expansion, Perturbative expansion and Asymptotic expansion, but I don't see offhand a general article on the subject. --Mark viking (talk) 00:28, 24 February 2014 (UTC)

I just created a short stub for the topic. Contributions welcome. --Mark viking (talk) 21:13, 23 February 2014 (UTC)

Requested articles/Mathematics/Logic?

The subpage Wikipedia:Requested articles/Mathematics/Logic? is not picked up by the bot that maintains Wikipedia:WikiProject Mathematics/Current activity and so new entries there are not flagged up. Is it possible to get that changed? And is there any special necessity to maintain this separation anyway? Deltahedron (talk) 07:37, 24 February 2014 (UTC)

I think what probably is useful is to keep the organization into mathematical logic, and subfields. I would be fine with having an L2 heading of "Mathematical logic" in the main page, with the subfields as L3 headings, and get rid of the subpage altogether. (There are probably several other fields that could benefit from such a structure as well.) --Trovatore (talk) 15:42, 24 February 2014 (UTC)

Upright versus italic d

I am in a dispute with Bub250 (talk · contribs) on Fundamental theorem of calculus. The issue is whether a roman or italic letter d should be used for differentials. Formerly, the article used italic d, as in:

\int f(x)\,dx.

Bub250 changed these to roman, as in:

\int f(x)\,\mathrm {d} x.

I firmly believe that this is wrong, regardless of the interpretation of d, and accordingly I reverted him. He reverted me, citing the IUPAP Red Book and ISO 80000-2 standards. We have both hit WP:3RR, and neither of us seems to be budging, so I think it would be helpful to have some outside input.

In the past, the community has applied WP:RETAIN to the question of upright versus italic d. That may still be the consensus, but since it has been a while since we had this discussion it may be worth reopening the issue. Ozob (talk) 18:23, 23 February 2014 (UTC)

Might I suggest the following process that each of you might follow:

Stop editing that article immediately
Find a (different) redlink in Wikipedia:Requested articles/Mathematics
Write a substantial article on that topic
Either

Come back here and explain why your preferred choice improves the encyclopaedia from the point of view of the reader

or (better)

Laugh ruefully, realise how extremely unimportant this issue really was, and put it all behind you.

Deltahedron (talk) 19:00, 23 February 2014 (UTC)

I have reverted the last edit of this user and left a warning on his talk page with references to MOS:MATH and our previous discussion here. D.Lazard (talk) 19:06, 23 February 2014 (UTC)

The consensus here in the many times this has come up before is that the italic d is by far the one more commonly used in sources, and that we should stick to that convention. S?awomir Bia?y (talk) 21:09, 23 February 2014 (UTC)

I should note that "upright d" is mathematically incorrect. (I know some students use them, but the usage is incorrect.) The reason is simple: "dx" means the diffenrial or the exterior derivative of x. Here, d is a function (from the space of functions to the space of one-forms). One can write d(x), but since d is linear, one can drop parathesis; like one writes Tx instead if T(x). Whenever you see the "upright d", the order is to eliminate them. -- Taku (talk) 03:25, 25 February 2014 (UTC)

I agree that upright d is mathematically incorrect, but I disagree that dx exclusively refers to an exterior derivative. It can also refer to a measure. In some sense this is more fundamental, because integrals of differential forms are ultimately defined by integrating in coordinate patches, and the integrals in coordinate patches are defined in terms of a measure. In a measure-theoretic context, for a function f, df is the Lebesgue-Stieltjes measure associated with f; in a sense this is the pullback of Lebesgue measure of R. Since d is still an operator on functions, it is still correct to italicize it and incorrect to romanize it. For measures like Lebesgue or Hausdorff measures which are defined directly (not as a Lebesgue-Stieltjes measure), the d is simply notation, but consistency seems to demand that it still be italic.

There is also the interpretation of dx as an infinitesimal (in the sense of Newton, Leibniz, and so on). Here the d is again an operator, so again it should be italicized. Ozob (talk) 05:34, 25 February 2014 (UTC)

This is a perennial problem. In things like differential topology the upright will always be used but in straightforward calculus learnt for hundreds of years the italic is used. I don't think we can decide that one form should be used everywhere, it depends on the circumstances. Dmcq (talk) 16:21, 25 February 2014 (UTC)

I think we should generally stick to what most sources in the relevant subject use. It bothers me that the argument for using an upright d almost always refers exclusively to a (paywalled) ISO standard, as if that should somehow trump every other mathematical style guideline. S?awomir Bia?y (talk) 16:39, 25 February 2014 (UTC)

This should be in WP:MOSMATH; I've been told that the upright d should be used in integrals, but it's often too difficult to implement. I don't have any elementary textbooks to determine the current usage in print. -- Arthur Rubin (talk) 20:13, 26 February 2014 (UTC)

It is in the section WP:MOSMATH#Choice of type style, where both roman and italic forms of the differential are claimed to be correct. --Mark viking (talk) 22:23, 26 February 2014 (UTC)

AfC submission no 2

Wikipedia talk:Articles for creation/Multivariate metamodelling of mathematical models. FoCuSandLeArN (talk) 15:47, 26 February 2014 (UTC)

This seems like original research to me. At least there appears to be no identifiable reference that supports the topic of the article as a whole. But this is far outside my area of knowledge, so YMMV. S?awomir Bia?y (talk) 17:46, 26 February 2014 (UTC)

We already have an article on this general topic using the more familiar name of surrogate model. This AfC article seems like a perhaps unintentional POV fork of surrogate model; it spends most of the prose extolling the advantages of using such a model, but doesn't acknowledge that almost all systems requiring a surrogate model are multivariable in nature. Right now, I cannot see how this fork is notable--most of the refs are primary refs about examples of surrogate models rather than discussing the subject directly. Note that the article metamodeling is about metamodels in software design, which is a different concept than that presented here. --Mark viking (talk) 19:16, 26 February 2014 (UTC)

I concur with this evaluation. Also, there is the whole book dealing with the subject, The simulation metamodel. I would suggest the author to rework/expand "surrogate model" page, rather than write a separate essay, as well as browse wikipedia for the subject/keywords, to draw the connections, make cross-links. I don't know how communication in AFC is carried out (the afc page does not have a talk page: it is a talk page itself). I will point the user in his talk page to this discussion. Staszek Lem (talk) 23:07, 26 February 2014 (UTC)

K(n,n) equation

Anybody here acquainted with the K(n,n) equation? -- Crowsnest (talk) 07:02, 26 February 2014 (UTC)

It's a variant of the KdV equation used for studying compactons, a variety of soliton with compact support. See for instance, [5]. --Mark viking (talk) 01:11, 27 February 2014 (UTC)

Miss-matched and tags

I've been doing a scan of wikipedia articles for miss-matched and tags. Things like ex. Anyway there are a fair number of maths articles (357) with such problems. You can see a list at User:Salix alba/subsup. For the most part the normal renderer works fine and manages to correct the problem, however the Visual editor makes different assumptions so things look a bit odd. If anyone fancies fixing a few of these that would be great.--Salix alba (talk): 08:08, 26 February 2014 (UTC)

I fixed Dirac equation and Zero sharp which are on my watch list. I could not find the error in Mass in special relativity. JRSpriggs (talk) 10:03, 26 February 2014 (UTC)

Found it. -- HHHIPPO 10:23, 26 February 2014 (UTC)

To help spots these things I written a bit of javascript which displays lines with errors. To use add the line

to your Special:MyPage/skin.js. This will add an entry 'SubSup' to your toolbox. Clicking on that link will open a window showing the lines where the tags don't match.--Salix alba (talk): 13:30, 26 February 2014 (UTC)

There's enough of them so a general mismatched tags check and fix should be stuck into some robot and standard checks somewhere. Dmcq (talk) 14:03, 26 February 2014 (UTC)

I fixed several more articles and your tool was a very great help. However, it sometimes indicated that there was no problem in one of the articles even though that article was on your list and the revision history indicated that no one had previously fixed it. JRSpriggs (talk) 08:40, 27 February 2014 (UTC)

There is now a discussion at Wikipedia talk:WikiProject Check Wikipedia#Mismatched sub and sup tags. Sees like a check for these may be added to some bots, AWB etc. My list is a bit dated being generated from dumps rather than live versions. There are some cases like ref correct markup which get listed in the dumps but the javascript tool does not report.--Salix alba (talk): 10:06, 27 February 2014 (UTC)

Total free access to Royal Society History of Science journals for 2 days on March 4th and 5th !!!

As Wikipedian in Residence at the Royal Society, the National Academy for the sciences of the UK, I am pleased to say that the two Royal Society History of Science journals will be fully accessible for free for 2 days on March 4th and 5th. This is in conjunction with the Women in Science Edit-a-thon on 4 March, slightly in advance of International Women's Day, on Saturday March 8th. The event is fully booked, but online participation is very welcome, and suggestions for articles relevant to the theme of "Women in Science" that need work, and topics that need coverage.

The journals will have full and free online access to all from 1am (GMT/UTC) on 4th March 2014 until 11pm (GMT/UTC) on 5th March 2014. Normally they are only free online for issues between 1 and 10 years old. They are:

Notes and Records: the Royal Society journal of the history of science
Biographical Memoirs of the Fellows of the Royal Society

The RS position is a "pilot" excercise, running between January and early July 2014. Please let me know on my talk page or the project page if you want to get involved or have suggestions. There will be further public events, as well as many for the RS's diverse audiences in the scientific community; these will be advertised first to the RS's emailing lists and Twitter feeds.

I am keen to get feedback on my personal Conflict of Interest statement for the position, and want to work out a general one for Royal Society staff in consultation with the community. Wiki at Royal Society John (talk) 12:17, 28 February 2014 (UTC)

Fibred category -> Fibered category

I've started a requested move at Fibred category. Participations are very welcome. -- Taku (talk) 12:55, 28 February 2014 (UTC)

Four-paragraph leads -- a WP:RfC on the matter

Hello, everyone. There is a WP:RfC on whether or not the leads of articles should generally be no longer than four paragraphs (refer to WP:Manual of Style/Lead section for the current guideline). As this will affect Wikipedia on a wide scale, including WikiProjects that often deal with article formatting, if the proposed change is implemented, I invite you to the discussion; see here: Wikipedia talk:Manual of Style/Lead section#RFC on four paragraph lead. Flyer22 (talk) 15:09, 28 February 2014 (UTC)

Help needed with eight links to Index (mathematics)

Index (mathematics) is a disambiguation redirect, and happens to be one of the last links needing to be cleared for the February 2014 list of most linked disambigs. The seven pages linking to this title are:

Distortion synthesis
Differential geometry of surfaces
Timeline of numerals and arithmetic
Timeline of mathematics
Wall-crossing
Fritz John conditions
Residual feed intake

If someone with the requisite knowledge could go correct the link to Index (mathematics) in these seven pages, that would be most appreciated. Cheers! bd2412 T 15:48, 25 February 2014 (UTC)

All done - thanks! bd2412 T 23:35, 25 February 2014 (UTC)

To BD2412: Unfortunately, the correction was erroneous in the articles 2 and 5, linking to indexed family instead of winding number. I have corrected these. In the 7th article, I do not know what is a "resource allocation theory index", but the link to indexed family is certainly wrong. The link to winding number in the first article seems also dubious. D.Lazard (talk) 12:18, 28 February 2014 (UTC)

I assume someone from this project applied those fixes after I posted this request - so to the extent that fixes were erroneous, that is a matter to take up with whichever editor made that edit. bd2412 T 13:12, 28 February 2014 (UTC)

Article 1 and 7 are not mathematics articles. Thus I have replaced the controversial wikilinks by {{clarify}} templates. Now, all are done. D.Lazard (talk) 16:16, 28 February 2014 (UTC)

Mar 2014

"Numerical cipher"

As far as I know, numerical ciphers are just ciphers that translate a message into a sequence of numbers. So Bifid cipher isn't equivalent. The redirect may have come from Numerical_cipher in the cryptography wikia. --Mark viking (talk) 13:33, 23 February 2014 (UTC)

I wouldn't trust anything coming from Wikia. What should we do with this redirect then? -- 70.50.151.11 (talk) 04:02, 24 February 2014 (UTC)

I've nominated it for deletion -- 70.50.151.11 (talk) 08:05, 27 February 2014 (UTC)

I've proposed at WP:RFD#Numerical_cipher that this be changed to redirect to Cipher (disambiguation). As far as I understand it, the use of the word cipher was common in the 16th and 17th centuries to mean zero, and often spelt cypher before English spelling got standardised (if we can call it that) in the late 18th to mid 19th centuries. I think it is perfectly reasonable to have it as a DAB (doesn't Isaac Newton in his Principia Mathematica on the differential and integral calculus calling the cheat of dividing by zero "the cypher"? Or was it John Napier doing logarithms? I forget which and most of my books are in store so can't check it from RS, and obviously Wikipedia is not in itself an RS so there's no point looking up what Wikipedia says about it. Si Trew (talk) 14:09, 1 March 2014 (UTC)

Catching up on accessibility issues/debate?

I have never edited or looked at a talk page of any Math article. I haven't even browsed the archives of this page yet. I am a naive and innocent passerby. A simple user who happens to have an editor account from other interests. I see the FAQ above and I know my questions and opinions are familiar and well-worn territory. However the FAQ doesn't sate my curiosity. Is there perhaps a famous thread or talk page or external blog post or something that really digs into the issue of accessibility of math articles?

My own feeling isn't about a specific article, but it can be summed up by my own behavior: if I'm searching on google for most topics and I see a result from wikipedia, I'm happy and always check it out, and often that is the end of the search. If I'm searching for something Math related and I see a wikipedia result, my first reaction is to avoid clicking on it, and if I click on it I'm _always_ disappointed by what I read. I _always_ have to keep digging for an alternate explanation. Why this is exactly is a bigger topic, but I wanted to just get some pointers first before I trot out the same old complaints. Silas Ropac (talk) 01:30, 25 February 2014 (UTC)

Here are some recent thoughts on this subject.

Wikipedia_talk:WikiProject_Mathematics/Archive/2013/Nov#A_couple_general_ideas

Wikipedia_talk:WikiProject_Mathematics/Archive/2013/Jun#Linear_function.2C_Linear_Equation.2C_Linear_Inequality_full_of_errors_and_inconsistencies_and_.22matheese.22

Wikipedia_talk:WikiProject_Mathematics/Archive/2013/Jun#A_wild_idea:_multi-tiered_maths_articles_to_match_the_target_audience.3F

Wikipedia_talk:WikiProject_Mathematics/Archive/2013/Feb#Linearly_ordering_the_mathematics_articles

I, too, have thoughts on why this is a perennial issue, but I'll save those for another time. Ozob (talk) 01:45, 25 February 2014 (UTC)

I think Wikipedia is more successful in its coverage of mathematics than in any other subject. (Nonetheless, I think there are vast areas of imperfection in Wikipedia's coverage of mathematics.) Michael Hardy (talk) 06:32, 25 February 2014 (UTC)

I think there is a middle territory between the elementary and the advanced that we don't generally do very well. In my own experience, areas like differential equations, special functions and to some extent linear algebra seem to be very incomplete and not well-done. S?awomir Bia?y (talk) 12:24, 25 February 2014 (UTC)

This has been said many times before, here and elsewhere, but the fundamental problem is that "math cannot be explained". In mathematics, you have to put real efforts to understand a concept you didn't know before. Wikipedia does not/is not meant to solve this. For example, I've always thought the definition of spectral sequence is very dry; the concept made sense "only after" doing concrete computations with simple and not so simple examples. Our spectral sequence is, not surprising, dry and didn't help much when I was learning the subject. (Coincidentally, if I were writing it, I would stress the exact couple of a filtered complex). -- Taku (talk) 14:03, 26 February 2014 (UTC)

"I think Wikipedia is more successful in its coverage of mathematics than in any other subject." Has there ever been an objective poll done by the wikimedia foundation or someone external? Comparing satisfaction on various subjects? I'm not asserting that I'm right or you're wrong, but just wondering if there is any objective data out there? Particularly that focuses on users and not editors.

However I guess I have to back pedal some. As I click through many dozen Math articles I see a much tamer situation than I had in my head. In my head based on math articles viewed over the last few years, and some recent clunkers, I was concluding that the math articles were allowing and encouraging the content to simply be pretty much all equations. That a pile of equations was seen as a reasonable explanation for any math concept.

While I feel there are various levels of domain knowledge required to understand articles throughout wikipedia, equations are a special case because they are essentially another language. It's as frustrating as if you looked up an article on Chinese literature, in the English wikipedia, and found a wall of Chinese characters. And then on the Talk page you read the editors insisting "only Chinese can adequately explain Chinese literature". That clearly would not fly.

However I'm not really seeing that as an endemic problem here. I do see tons of equations, but I'm assuming math people expect and require that. But I also see lots of attempts to explains things with words. I think when I see an article that I feel does not achieve a good split, I should just comment on that article's talk page. I was sort of jumping to the conclusion that it was a lost cause to address a specific article, that the whole math ship was going down, but perhaps not.

Here is a funny example though: Bayesian network. That article actually has plenty of explanations later on, but they make a concerted and heroic attempt to scare off the reader before they get to the prose.

Since I can't find the examples I was thinking of, here is a more obscure one: Volume of an n-ball. The lede is only 43-words but there are 50+ lines of equations. I read on the math style guide that you should realize people generally will skip over equations and write accordingly. But reading just the words here there is zero sense of flow or explanation of anything. It feels like a laundry list of facts. Perhaps that is what mathematicians expect in wikipedia articles? I can imagine volunteers cheerily typesetting all these equations for hours, then grumbling over spending 20-30 seconds on the lede. It wouldn't be a big deal except the article is B-class. I'm guessing "number of equations" is pretty high on the assessment criteria for math articles?

I do wonder if equations should be banned from the lede: Linear independence, Cross correlation, the style guide says "It is even more important here than in the rest of the article that the text be accessible".

Now of course the really advanced stuff is incomprehensible but that is it's own problem: Hopf fibration, Special unitary group. I highly wonder if it's possible to write anything interesting and accessible about really high level math, I have never seen it done.

I don't buy that "math cannot be explained", you have to truly work and understand it. I can read about Math without understanding it. I think that is a problem with a lot of the advanced math articles, they don't have enough about the thing. The history of its discovery and use, the importance, what concepts does it relate to. These are things any reader should be able to take away.

But I don't see the broad sweeping problem I thought. I see articles mostly attempting to be accessible, succeeding or failing to various degrees, but not a conspiracy by any means. Perhaps there are ways to steer the overall a little better, like requiring non-trivial and accessible ledes for C class and above. I think that would be a good gesture towards the average reader. 14:20, 26 February 2014 (UTC)

I don't think Volume of an n-ball is really that bad. It's not a great article, but it conveys the necessary information. In article like that, there are naturally going to be quite a few formulas, and this one is not even all that heavy. I don't think that all articles must be pitched at "any reader". We should pitch articles at likely readers. An article on the volume of an n-ball should not be targeted at readers who don't know what an n-ball is to begin with. I generally think that equations should not dominate the lead, although it would be a mistake to rule generally on that matter. For instance, obviously articles that are about an equation should be permitted to have that equation in the lead. I do think that generally equations in the lead, and to a lesser extent the text, should be minimized wherever that is reasonable. As to the history of the subject, it can be surprisingly difficult to find good accounts on the history of mathematics. Often one has to go so far as to track down and consult original articles, obscure papers in the history of mathematics, and so forth. Mathematics is unfortunately not a subject where it is common to refer to the original papers of Cauchy or Riemann or Poincare or whomeve, and unfortunately there is nothing Wikipedia can do about that. I can count on one hand the number of mainstream mathematical textbooks I have read that actually give a thorough and well-researched account of the history if their subjects. S?awomir Bia?y (talk) 15:25, 26 February 2014 (UTC)

I agree Volume of an n-ball is kind of an oddball case. I don't see how it's a B-class article, but it's not worth belaboring that example. I was really just using it to point out what I think are some less-good features which occur often in Math articles: inaccessible ledes and over-reliance on equations. However as I said above I was actually really impressed to see these problems are much less common than I thought, really I think there are tons of articles, I'd say definitely the majority, that do a good job on these points. However I think these are common pitfalls that should be actively warded off. It's like over-summarizing in book articles, it's just a common mis-step that is endemic to the topic.

I disagree that "likely audience" should be the goal.The FAQ above says the target is "the interested layman" except then it immediately punts and says "this is not always possible". That is way too vague. When is it not possible? How do we determine if it's not possible or the article is just not written well? Importantly: if it's not possible do we then give up completely and accessibility becomes a non-goal? Or is it still useful to strive for a somewhat accessible lede even if the article itself is super advanced?

WP:TECHNICAL says articles should be "understandable to the widest possible audience" which mostly means "understandable to a general audience". It talks about all they cases and ways most articles should be accessible to everyone. For the exceptions "like advanced mathematics" it still says "effort should still be made to make the article as understandable as possible, with particular emphasis on the lead section." It says "it is particularly important" for the lede "to be understandable to a broad readership. Readers need to be able to tell what an article is about, and whether they are reading the correct article, even if they don't already know the topic in detail". All of WP:EXPLAINLEAD is super relevant. I particularly note the request to include "the place the topic holds in its field of study" and "what (if anything) the topic is good for". I feel like that is blatantly and widely ignored.

I sympathize with the difficultly of doing any of these things for math articles, especially advanced ones. It's a really really hard problem. I just feel like the wikipedia math community has somewhat punted by saying "we are special, we just can't do it, it's impossible". I think that's a mistake, I think the goal should be to do much better, and that this can be done without removing the technical content for expert readers.

One way to improve things is just to tell people "try harder to make things accessible" but of course that will accomplish nothing. I think it would take systematic change and strong leadership to declare that accessibility is a huge goal for all articles, and to work towards that goal. It might take many years or a decade to really effect that kind of change. But I think future-wikipedia would be a much better thing if it were done well.

I'm not a math editor and not likely carry this flame. So really I don't expect much to change from my comments. But I just wanted to give my two cents since to me the problem is crystal clear. I suspect I represent a decent chunk of people who use math articles, but I'm sure math-intensive people are a bigger faction, and that is why the problem is not seen as a problem. Silas Ropac (talk) 19:53, 26 February 2014 (UTC)

I think you'll find us in agreement on the broad points. Quibbling over "general reader" versus "likely reader" isn't terribly constructive. The bigger picture is that there are many mathematics articles that need to be improved (both in terms of accessibility and otherwise). I don't mean to diminish the achievement of editors who have struggled to prove the many articles that are very good. Even the articles on special functions that I love to gripe about seem to have improved substantially in the last few years. I still think we have major weaknesses in core mathematical areas like linear algebra and differential equations. Progress in those areas hopefully comes in fits and starts. "Carry the flame" is an apt analogy. S?awomir Bia?y (talk) 22:15, 26 February 2014 (UTC)

I am broadly in agreement with both of you, but I have something specific to add. I wrote most of Volume of an n-ball, starting about a year and a half ago (here) and I have some insight into why it is the way it is.

I got interested in the subject because I decided that this formula was a basic computation that I should really understand; I wasn't satisfied anymore with nodding my head at every step of someone else's derivation. In a very strong sense, I wrote the article for myself. And it shows; I don't know anything about the history of the computation of these volumes, and I don't know who needs volumes of n-balls in their work (I don't), and since the article had neither of these before, it has neither of them now. I don't know much about volumes of n-balls. I just felt like learning about them. I did demand of myself, however, that I knew how and why the formulas worked, and in the process I converted the article from a pile of equations to something that, perhaps despite appearances, has exposition.

My feeling was that the primary reason why someone might read the article was because they would either want to know how the formula was derived or they would want to look up the formula. I realized that it would be easy for me to make the article useful reference, so I put quite a lot of formulas at the beginning. I added all the derivations I could find (I think the one using Gaussian integrals is really the "right" one in a sense). And I added a little other content, like the asymptotic formula in high dimensions. I don't think it's a stellar article, but I achieved my goals for it, and I'm pretty happy with how it turned out. But it's not, and never was, intended for a general audience. Ozob (talk) 03:29, 27 February 2014 (UTC)

I too write for people like me who want to know something about certain rather specialised topics in mathematics, the ones I happen to be interested in. It seems reasonable to assume that those readers already have some mathematical background. If other editors feel that articles need more explanation to make them easier to access by readers with less background than I'm assuming, then they are perfectly free to add that material. I'm not very interested in being told by other people that I should be doing what they themselves are free to do. Deltahedron (talk) 07:31, 27 February 2014 (UTC)

Well, I don't always write for myself, and I do believe that the "interested layperson" is the right audience to aim for. When I work on an article like Derivative or Chain rule, I try to aim for a less sophisticated reader; but I don't think I always succeed, and I certainly haven't written much, if any, brilliant prose. I don't know if I could ever produce an article of the quality of Homotopy groups of spheres, which I think is really outstanding. Good exposition is a very hard problem which I don't know how to solve. Ozob (talk) 15:15, 27 February 2014 (UTC)

Ozob and Deltahedron make excellent points. The fact that everyone is a volunteer with their own intentions and goals for adding content is a huge factor in all of wikipedia. As is the fact that articles get built over time. I imagine it's well documented that editors who participate at different stages of an article's development have different personalities and motives. Perhaps my criticism of Math articles is as simple as: wikipedia is not done yet. I'm having deja vu that I've come to that realization more than once, that incompleteness looks like bias. Maybe articles which are inaccessible and equation-heavy today will be fleshed out over time. Certainly the best Math articles on the most common subjects seem really good today, so maybe it's just a question of time and resources.

So long as people are additively contributing all is well. However if there are edit wars or turf battles where people trying to make articles more accessible are beaten down by those trying to keep them "pure" and expert-centered, then that is bad. I haven't edited Math articles or read many talk pages, so I can't say whether this is a problem or not. Like I said before my main take-away from this thread is if I wanted to help I should address a specific article not the whole project, which I think is a wikipedia-wide rule of thumb.

One Math-specific issue I didn't raise yet. Does WP:NOR apply to equations? I see sources cited in Math articles, but I rarely see citations on specific equations. Like in Volume of an n-ball do those 50+ equations appear verbatim in the one cited reference? Or, as seems more plausible, do Math editors take the liberty to derive or produce original content? Is there some kind of official exception to WP:NOR for Math, or is it sort of just understood that one wouldn't get very far writing about Math if one didn't do some Math in the process?

I don't really don't have a pre-conceived opinion on that one. My guess is the cat is so far out of the bag and the tide of new equations spewing forth from editors minds so torrential it would be impossible to ever enforce a strict citation policy.

However going back to my "wikipedia isn't done" comment it does lead to point. In most subjects common topics have copious references but as one narrows scope, the number of sources dwindles and the amount of content in those sources dwindles until there is simply nothing to write about. But if Math editors are allowed to more or less generate content then the natural taper goes away.

This is speculation, but it suggests the lifecycle of a Math article is just different from other types of articles and can be mis-interpreted. Rather then getting built a tiny bit a time, as cited facts are bolted on, Math articles can be quickly inflated with content, but then they have to be whittled down and framed with explanations. Again I'm making this all up, does this ever happen? Silas Ropac (talk) 15:04, 27 February 2014 (UTC)

Re WP:NOR: there is a provision WP:CALC for simple calculations and derivations, which was left deliberately vague to allow some leeway for mathematics editors to supply simple proofs. It has been extensively debated (see Wikipedia_talk:No_original_research#Counting_--_possible_addition_to_WP:CALC, Wikipedia_talk:No_original_research/Archive_58#Routine_calculations and possibly elsewhere (?)). I sort of recall it was a subject of a big hassle few years ago, about an editor who was supplying a ton of original proofs, but I don't recall the details (was it User:Mathsci perhaps?). Maybe it's worth pursuing for further refinement. No such user (talk) 15:59, 27 February 2014 (UTC)

Gosh they are talking about counting and arithmetic. My gut is people are doing major derivations and elaborations and enumerations and manipulations of formulas. But I don't know at all for real, I just get that impression looking at the articles, it looks like some of the people kind of say "well what else can I say about this" and just kind of come up with stuff which is mathematically true, but isn't sourced. But this could be "don't ask don't tell" in that 99% of editors are not going to be able to call anyone out on these transgressions. Or maybe there are no transgressions I'm one of the 99% here I really can't say. Silas Ropac (talk) 05:24, 28 February 2014 (UTC)

Why would it be necessary for all of the equations to appear verbatim in one single source? That's not even a reasonable standard for nonmathematical articles. There is of course some leeway in how things are presented, but this is the same leeway that is afforded to articles in any other subject. Regarding citations in mathematics articles, there has generally been resistance to over-use of inline citations (so you will seldom see references attached to every single equation) in favor if the recommendations of WP:SCICITE. While many mathematics article would certainly benefit from more citations or clearer attribution, it doesn't necessarily mean that original research is being committed. This is especially true of content that can be found in essentially any textbook in the relevant subject area, which actually covers quite a lot of our mathematics content. It's not unusual for a single textbook to serve as a general reference for an entire article. (The opposite situation, where a single textbook is referred to assiduously at every line if the article really looks quite amateurish and silly.) S?awomir Bia?y (talk) 16:29, 27 February 2014 (UTC)

Why would it be necessary for all of the equations to appear verbatim in one single source? It's not necessary in general, but in this case there were 50 equations and one source, therefore my own rudimentary math skills lead me to believe all the equations must be verbatim from that source. I mean that's the general idea, that facts are from a source and not the editor's fertile imagination? Now I can't really read any of this stuff, but my guess just from glancing at the squiggly lines, and the quantity of squiggly lines, is that there is rampant "don't ask don't tell" policy in play with Math articles. Forbidding Math editors to come up with their own equations would go over about as well as forbidding humming at a song-writers convention.

And the WP:NOR question was just out of curiosity anyway, my main concern was accessibility. I think I've more or less bottomed out on the issue by admitting there isn't a big anti-accessibility cabal which is going around obfuscating all the articles so beginners can't understand them. Instead I feel that math is hard, or at least advanced math is hard, and without a lot of effort no math article is going to be super friendly. And so a lot of the big and popular articles are in fact quite friendly, but a lot of the advanced and less common articles are not. That that's just the state of things in 2014, and maybe it will get better over time.

I pulled over thinking there was a big injustice being done and all I saw was a bunch of mathematicians working on a construction site, with one yelling "move on, nothing to see here". Silas Ropac (talk) 05:18, 28 February 2014 (UTC)

I wholeheartedly agree with this sentiment, especially that "without a lot of effort no math article is going to be super friendly". Speaking from personal experience, it is really hard (for me at least) to write articles that are both suitable for an encyclopedia and accessible to a wide audience. I don't even claim to be all that successful at it: there are some articles that I have worked on that I am quite happy with, and others less so. The latter have to be just good enough, unless and until someone makes a better attempt. It's comforting to know that Wikipedia is a work in progress. S?awomir Bia?y (talk) 18:30, 1 March 2014 (UTC)

In a way, you're right, there's no natural taper for mathematics. No matter what problem you're considering there is always more to say; Henri Poincare once said, "There are no solved problems in mathematics, only problems that are more or less solved." But there is a natural taper for mathematics articles. Not everything that you can say about a subject is interesting, and not everything is notable enough to be the subject of an article. Because we are supposed to be able to cite everything to a secondary source, the scope of Wikipedia is vastly more limited than that of mathematics itself.

Regarding Volume of an n-ball, no, at some point I looked at the one cited source and it didn't have all of those equations or even most of them. The article is sorely lacking references. However, it ought to be possible to find references for all the facts in the article (equations or otherwise; remember that equations are just a kind of fact). Ozob (talk) 03:21, 28 February 2014 (UTC)

Right I agree that WP:N saves us from a library of babel of Math articles. I was relieved when I realized that. So instead I think what you have is just the quirk that for Math articles one can fairly easily inject completely true but unsourced information. That's pretty hard to do in non-Math articles, unless you just happen to have the first-person knowledge. But I don't see that as a showstopper by any means. I can imagine debating WP:NOR and fighting against each and every non-sourced equation, but that doesn't interest me. I feel as long as more mature articles are more accessible and rely less on equations, I'm not sure there is anything to argue about, the bottom line seems to be just that having more mature articles is better for everyone, which is a milquetoast platform. Silas Ropac (talk) 05:38, 28 February 2014 (UTC)

WP:V is also important. Everyone makes mistakes, and I've certainly written things that I was convinced were true but in fact were false. Once you've seen yourself make enough mistakes (on Wikipedia or otherwise) the necessity of verifiability becomes clear.

Also, many (but not all) of the equations in Volume of an n-ball fall under WP:CALC. The very first one does not, and I think the next two probably do not either. But the three after that are manipulations that could be done by a high school student; I think they are covered by WP:CALC. While everything in the section "Recursions" can be derived in an elementary way from the previous section (and so I think WP:CALC might apply), I'm sure that citations for the first two formulas exist, and the article would benefit from them. I believe the two following formulas fall under WP:CALC; certainly the second equality in each does. The entire table in the "Low dimensions" section is covered by WP:CALC. The formulas in the "High dimensions" and "Relation with surface area" section need citations (but the last four in "Relation with surface area" go together; any source with one will have all four). Then we are in the proofs section. The proofs themselves need citations, but those citations will cover all the formulas that appear. The "Balls in L^p norms" section needs a citation for its first equation (though WP:CALC might cover it in light of the equation cited below), but then most of the rest counts as routine calculation. The last two displayed equations are both covered by the article's one reference. Altogether, I think that if the article were to have inline citations, it would need about fifteen more citations than it does presently to cover all the equations. Many of these would be citations to the same source or sources.

I've just added one citation to the article. Ozob (talk) 15:19, 28 February 2014 (UTC)

If an able editor makes a derivation in a math article to make it clearer to the "intended audience" it is usually not original research in any reasonable sense. It might be original, but there is typically nothing that warrants the research label, even if it is a derivation that is not to be found anywhere in the references. Straightforward application of everyday mathematics to obtain (even new) formulas just isn't research.

My 2c: Sourced equations (and derivations) are preferable to unsourced ones, but unsourced equations (and derivations) are better than no equations (and derivations). Errors (unavoidable whether the material is sourced or not) are quite likely to be caught. Now, Wikipedia has a different definition of original research, see WP:NOR. The term "research" is tied to that something isn't in print (or it is simply unknown where it is to be found) in "reliable sources". If editors just use their good judgement (they usually do that), I think they strike a fine balance. YohanN7 (talk) 17:56, 1 March 2014 (UTC)

Little orphan Annie

(No pun intended. Except that actually, I couldn't resist.)

Anne's theorem is currently an orphan: no other articles link to it. Michael Hardy (talk) 17:17, 2 March 2014 (UTC)

Insertion of Original research in several articles

Maimonid has recently edited several articles for inserting in them some texts supported by unpublished Bensimhoun's articles. I have reverted one of these edits. However some of these edits may be partially constructive, and some other eyes would be welcome. These edits include edits in

Galois theory (reverted by myself)
Fundamental theorem of Galois theory
Algebraic integer
Integral element
Conjugate element (field theory)
Minimal polynomial (field theory)

D.Lazard (talk) 09:36, 2 March 2014 (UTC)?

At least one consists of adding as a reference a link to a PDF file uploaded onto Commons. This is obviously not a reliable source. Deltahedron (talk) 09:54, 2 March 2014 (UTC)

These results are so elementary that they do not need "reliable sources". They can be recognized as exact in few seconds by any person sufficiently experienced in algebra. The links to the documents with the proofs are a "bonus" here. If you think that these links are irrelevant, you could at least keep the corresponding assertions in the Wikipedia pages without linking to their proofs. Michael Bensimhoun (talk) 21:58, 2 March 2014 (UTC)

An interesting view, and one I am not entirely unsympathetic with, but Wikipedia has a policy on verifiability from independent reliable sources for a number of reasons. Firstly, so that readers, and other editors, can have some reasonable degree of confidence that the results are correct. Secondly, so that there is some degree of confidence that the results are worth mentioning. Thirdly, to prevent debates among editors, that would generate more heat than light, over points one and two. Deltahedron (talk) 22:09, 2 March 2014 (UTC)

If I'm not wrong, the problem is in the fact that I mentioned an unreliable source. What about not mentioning nothing at all, and to insert the assertion? Please, consider this paradox : on one hand, no conventional (reliable) journal would accept to publish elementary results. But on the other hand, Wikipedia do not accept publishing things that are not "explicitly" mentioned elsewhere in peer reviewed journals or books; so, there are mathematical truths and interesting observations that will be ignored for ever. Is it what you call "expansion of the knowledge"? In my opinion, a more intelligent point of view would be to "give a chance" to these mathematical truths, and to require a vote in the case where it is thought the result is suspect. Surely, for such elementary assertions, the exactness or inexactness would emerge very quickly. Michael Bensimhoun (talk) 22:42, 2 March 2014 (UTC)

It's not thought entirely polite to mention it, but here's the real issue. We're forced to hold a fairly tight line on "original research" (this is a Wikipedia term of art; it doesn't imply that anything is particularly original or research-like), because otherwise we would be overwhelmed with submissions from cranks and crackpots. We're not supposed to give much (theoretically, we're not allowed to give any) weight to an editor's credentials, so if it weren't for the OR policy, it would be very hard to prove that crankish submissions ought to be removed.

Unfortunately, it does sometimes create an obstacle non-crank editors adding useful material. But once you've been around a while, you'll probably agree that that's a necessary tradeoff. --Trovatore (talk) 23:11, 2 March 2014 (UTC)

As you might have noticed, proof outlines and supporting arguments with "unreliable references" will be challenged. But nothing prevents you from being bold. Proof outlines and supporting arguments without references may be challenged, but will not be challenged with certainty. YohanN7 (talk) 23:31, 2 March 2014 (UTC)

Let me clarify. Other editors may know of a "reliable" reference, or they may accept the argument as it stands or endow it with a "citation needed tag" for future improvement. Best is to drop a note in the articles talk page when adding unsourced material. Finding acceptable references on your own for every claim is notoriously difficult (and potentially expensive). Use your judgement. YohanN7 (talk) 23:41, 2 March 2014 (UTC)

I agree, this requires a common sense approach rather than enforcing rules for rules' sake and remembering the policies exist as a tool to serve a goal and are not really (primary) goals in their own right (and we have WP:IAR for that reason). So if you come across some obviously true material (as in easily recognizable to be true for anybody with some domain knowledge), simply don't challenge it. Of course if it gets challenged nevertheless sources will need to be added or in exceptional cases proof reading/verification by people with domain knowledge (in particular regulars of this portal) might suffice. Note that the latter only applies to things being obviously true for people with domain knowledge and may be considered an application of WP:IAR. The latter however cannot serve as an excuse for editors making unsourced edits all over the place or to cite their own unpublished results.---Kmhkmh (talk) 09:03, 3 March 2014 (UTC)

I agree with Kmhkmh. This is for this reason that I have not reverted myself all Maimonid's edits: some of them did contain not only reference to his original research, but also some text which may be useful. I had not the time for checking if this text needed or not to be challenged. D.Lazard (talk) 09:29, 3 March 2014 (UTC)

AfC submission - 04/03

Wikipedia talk:Articles for creation/AMS Centennial Fellows. FoCuSandLeArN (talk) 14:17, 4 March 2014 (UTC)

Merger of Pick matrix

Should Pick matrix get merged into Nevanlinna-Pick interpolation? Michael Hardy (talk) 18:22, 6 March 2014 (UTC)

Doing a Gscholar search for "Pick matrix" shows that, of the hits on the first two pages, most of the uses of the matrix are in the context of Nevanlinna-Pick interpolation. A merge seems reasonable to me. --Mark viking (talk) 19:14, 6 March 2014 (UTC)

Rotations, their group, and related Lie groups

Conflict in Rotation group

Short history:

JohnBlackburne (talk · contribs · deleted contribs · logs · edit filter log · block user · block log) undid my edit; ensuing discussion led to a stalemate.
JohnBlackburne initiated a requested move where sophisticatedly hid the question of WP:PRIMARYTOPIC of the term "rotation group" in a nominal topic, what to do with a dab page.
Two persons threw their "Support per nom" votes without any supplementary arguments about the particular primary topic problem.
JohnBlackburne used these two votes to press for redirecting Rotation group (edit | talk | history | links | watch | logs) to orthogonal group, a confusing solution as a good mathematician should realize.

I hope local frequenters will demonstrate a more thoughtful approach than the WP:RM people and so. Incnis Mrsi (talk) 11:12, 15 February 2014 (UTC)

You are disputing the outcome of the move: Talk:Rotation group (disambiguation)#Requested move. But the outcome is clear. I proposed a move, with reasons and referring to previous discussions which prompted the move, so there had already been plenty of argument. It's understandable in such cases when editors don't feel they need to restate the arguments. Of the responses two supported my reasoning, so there is consensus for the move as described in the request.

You only disagree what the primary topic for rotation group should be. In addition to the reasons given in the RM I can give two more if it helps. First the orthogonal group is known as the rotation group. See the first line of that article - I added that with a source after looking for a suitable target, before proposing the RM. The other reason is rotation group used to refer to an orthogonal group, Rotation group SO(3). That was moved from rotation group two years ago. So for much of its existence "rotation group" referred to an orthogonal group, just a particular one not a general one. -- Preceding unsigned comment added by JohnBlackburne (talk o contribs) 12:45, 15 February 2014?

This conflict is based on a big mathematical error. Please, correct it ASAP: It is said at several places (at least at the first lines of orthogonal group and of rotation group (disambiguation)) that rotations and orthogonal transformations are same thing. This would imply that the symmetry with respect to a line in the Euclidean plane would be a rotation! The correct wording is that the orthogonal group is the group of the isometries of a Euclidean vector space (that is a real vector space equipped with a positive definite quadratic form, such as the dot product). In dimension 2 and 3, the rotation group is SO(2) and SO(3) (in higher dimension, I do not remember if the rotation group is SO(n) or if the rotations have a more restrictive definition). D.Lazard (talk) 13:25, 15 February 2014 (UTC)

I don't see the errors you refer to. It says in orthogonal group and in the disambiguation page that orthogonal group and rotation group (usually) refer to the same thing, which is the reason for the move, supported by the arguments in the RM and above. rotation group, not rotations, which are something different and much less formally defined. But if you think it could be improved go ahead, or describe what changes should be made here.--JohnBlackburne^words_deeds 14:15, 15 February 2014 (UTC)

It is wrong that "orthogonal group and rotation group (usually) refer to the same thing". "Rotation group" is the same thing as "special orthogonal group". D.Lazard (talk) 14:30, 15 February 2014 (UTC)

I see what you mean. The problem is that's the same article: special orthogonal group redirects to orthogonal group. I would say it's less clear cut which is the rotation group - the special orthogonal group is the group of all proper rotations, so the group of all (proper and improper) rotations is the orthogonal group. But the outcome of the move would be the same: rotation group would redirect to orthogonal group (if it's made to redirect to special orthogonal group a bot will quickly change it back as that's a double redirect). Any subsequent problems should be addressed by editing the article and disambiguation page.--JohnBlackburne^words_deeds 15:00, 15 February 2014 (UTC)

Will creation of the special orthogonal group article be an acceptable compromise? I am willing to settle on it, but John's abomination in the present form can't be tolerated. Incnis Mrsi (talk) 14:55, 15 February 2014 (UTC)

They were merged a long time ago. I don't think so old an article is a useful guide but it's hard to see how a separate article will help. There's almost no content in orthogonal group unique to the special orthogonal group, so you end up either with a stub with almost nothing in that's a disservice to readers, or largely duplicating orthogonal group with all the problems that involves of extra maintenance, articles getting out of sync.--JohnBlackburne^words_deeds 15:10, 15 February 2014 (UTC)

You are not right: there are some correspondences (see the table) that could be spelled separately for G- and S-cases; note that [~~each other two columns have~~ // my grammar mistake: should read "each of two other columns has" Incnis Mrsi (talk) 17:34, 15 February 2014 (UTC)] a pair of separate articles. Also, the orthogonal group virtually excludes the indefinite orthogonal group case, whereas the Special orthogonal group (edit | talk | history | links | watch | logs) should not do it and may consider all determinant-1 matrices/operators that are orthogonal with respect to certain quadratic form, including SO(3;1), as well as relevant subgroups such as SO(3;1)⁺. Incnis Mrsi (talk) 15:32, 15 February 2014 (UTC)

It should be obvious that SO(3) is the rotation group and that nobody thinks of O(77) as a group of rotations and that SO(n) is rotations in n dimensions. It is also obvious that SO(3) (whatever you call it) deserves an article of its own. YohanN7 (talk) 15:44, 15 February 2014 (UTC)

And it has one: Rotation group SO(3). As can be seen from that, and Rotations in 4-dimensional Euclidean space the interesting properties of SO(n) are most apparent from considering them for particular values of n. Circle group completes the set of low-index special orthogonal groups. The names could be more consistent but there's not an obvious right thing to call them.--JohnBlackburne^words_deeds 16:02, 15 February 2014 (UTC)

No big problem then, good. (I didn't read the above too carefully apparently.) I wouldn't oppose a split of Orthogonal group into O(n) and SO(n) (or whatever we choose to call them). I believe that there is enough "substance" in the two to make up two separate articles, at least in the long term. YohanN7 (talk) 16:58, 15 February 2014 (UTC)

@D.Lazard: stop to push your "SO(2), SO(3) and SO(4)" crap into the lead section of the orthogonal group: it reintroduced a confusion between real numbers and an arbitrary field that I once worked hard to eradicate. Re-join the discussion and express your opinion: would a new article be a solution, or ? Incnis Mrsi (talk) 16:52, 15 February 2014 (UTC)

@Incnis Mrsi: Undoubtfully, the primary meaning of orthogonal group refers to the reals. I have carefully rewrote the lead of orthogonal group for making this clear, by describing the generalizations (to other fields of other quadratic forms) after the main meaning. My so called "crap" has been introduced in a paragraph clearly (maybe not enough clearly) devoted to the real case, and these links, as well as the fact that these case have been widely studied, are important form an encyclopedic point of view. In my opinion, this is the confusion between the primary topic and its generalizations which is confusing. D.Lazard (talk) 17:18, 15 February 2014 (UTC)

@Incnis: This kind of pettifogging is unconstructive. Wikipedia articles often proceed from the specific, but common, to the general but uncommon. Even most professional mathematicians would consider the orthogonal group to be over the real numbers. When referring to groups over an arbitrary field, it is always either explicitly said, or is in the context of linear algebraic groups or similar. S?awomir Bia?y (talk) 17:21, 15 February 2014 (UTC)

I consider this as an implicit support for splitting. One hardly can substantiate such heavy emphasis on S groups in the lead section about a non-S group. Incnis Mrsi (talk) 17:34, 15 February 2014 (UTC)

If a split should occur, it should be by restricting Orthogonal group to the real case (related to Euclidean distance), and creating Orthogonal group over a field. Similarly, we have already Indefinite orthogonal group. D.Lazard (talk) 18:52, 15 February 2014 (UTC)

Which problem will be solved? The lead became bloated with the S-related stuff after your late edits, and it will remain bloated regardless of whether "non-standard" fields will be expunged or not. Incnis Mrsi (talk) 20:26, 15 February 2014 (UTC)

I don't have strong opinions about a split one way or another (implicitly or otherwise). I was merely responding to your apparent point that the case of the reals needs to be de-emphasized. S?awomir Bia?y (talk) 19:45, 15 February 2014 (UTC)

I meant primarily that Daniel's three links through redirects are self-contradicting: the article says there are O groups over any field, but sends the reader to articles about real groups via unspecific O(n) titles. I didn't say the real case has to be specially de-emphasized, but the lead section become bloated and a bit confusing after late D.Lazard's edits. Incnis Mrsi (talk) 20:26, 15 February 2014 (UTC)

We must not forget that the orthogonal group (over the reals) is not only a concept of pure group theory, but also an important geometrical concept, widely used in mathematics, physics and mechanics. On the other hand, as far as I know, the generalization over other fields is considered only in pure group theory. As the article must be accessible to a much wider audience than only group theorists, this must help to give a due weight to the primary topic (over the reals) and its generalizations. D.Lazard (talk) 23:06, 15 February 2014 (UTC)

The orthogonal group for a general quadratic form over a general field is certainly not "considered only in pure group theory", although it is indeed important there. It is important in, for example, number theory and field theory (see for example the books of O'Meara, or Lam, or Cassels). Deltahedron (talk) 07:24, 16 February 2014 (UTC)

Classical groups

Much of the content in the current lead in Orthogonal group should really be in Classical group. That article could well serve as an umbrella for articles on particular classical groups. See also Talk:Classical group#Not B-class. YohanN7 (talk) 22:02, 15 February 2014 (UTC)

It may be worth noting that the Encyclopaedia of Mathematics article Orthogonal group begins "An orthogonal group is a group of all linear transformations of an n-dimensional vector space V over a field k which preserve a fixed non-singular quadratic form Q on V" while Reflection group begins "A discrete group of transformations generated by reflections in hyperplanes". I personally prefer the more general definition of orthogonal group. Deltahedron (talk) 22:09, 15 February 2014 (UTC)

Will it help to solve the current problem, or it is an independent suggestion? Incnis Mrsi (talk) 20:26, 15 February 2014 (UTC)

It will not help solve the problem with the disambiguation page (if that is what is the current problem), but it can be taken into consideration if Orthogonal group is split. The stuff about bilinear forms need not be repeated in each classical group article, it is common to all of them except for SL(n, C) (and the exceptional ones if you count them as classical). By the way, I don't think we need to have such a broad interpretation of what a rotation is, SO(3) as the rotation group and SO(n) as a generalization would work. "Improper rotations", "rotations in spacetime" and the like serve no purpose really. YohanN7 (talk) 22:02, 15 February 2014 (UTC)

And by extension of my above reasoning, it would be strange to have "rotation group" redirect to "orthogonal group" or for it to have "orthogonal group" as the main dish. YohanN7 (talk) 22:14, 15 February 2014 (UTC)

The exceptional ones are not classical by definition. There is also a broad concept rotation (mathematics) article. @YohanN7: please, explain yet a time: which articles should, in your opinion, serve the O(n, F) and SO(n, F) topics? Incnis Mrsi (talk) 12:58, 16 February 2014 (UTC)

@Incnis Mrsi: I haven't explained even one time which articles should serve the general field topics. I'm thinking about the definition and classification of the classical groups in terms of bilinear (sesquilinear) forms. This should in my opinion go into Classical group in a more thorough way than today. I frankly have too little knowledge about groups over general fields to even have an opinion about where they should be treated. But I do feel that the fields R, C and H should be treated within the same article for each "abstract" group we treat separately. Probably then, the O(n, F), etc, should each have a section in the general O(n), etc, articles. Some people (the real connoisseurs) count the exceptional groups among the classical groups (but I don't). Yes, I have references supporting that statement, but this is not important. YohanN7 (talk) 16:00, 16 February 2014 (UTC)

Quaternions are a division ring, not a field. There is the GL_n (although with two incompatible natural representations), but there isn't neither SL_n nor O(n). You must reserve special clauses to define the determinant that isn't matrix multiplication-invariant at last, you must care about the order of factors everywhere (such as in bilinear forms), and you can't define orthogonality as a symmetric relation. One would be more successful in generalizing these groups to commutative rings than over structures where the multiplication does not commute. Incnis Mrsi (talk) 16:29, 16 February 2014 (UTC)

Division ring, non-commutative field, whatever. See Wulf Rossmanns Lie Groups - An introduction through linear groups for a thorough treatment of GL(n, H), SL(n, H), (S)U(p, q), Sp(p, q) and (S)O*(2n). These are groups over the quaternions, very successfully generalized to them. YohanN7 (talk) 17:42, 16 February 2014 (UTC)

See a follow-up at talk: Classical group #Matrix groups over non-commutative rings. Incnis Mrsi (talk) 12:20, 18 February 2014 (UTC)

But you are right about symmetric bilinear forms. They don't yield anything interesting (I think they are automatically degenerate, not sure, can check this out later) in the quaternionic case. I was thinking more generally in terms of all classical groups. YohanN7 (talk) 17:52, 16 February 2014 (UTC)

Rotation operator (vector space)

This title is problematical, not the article separated from its title. In absence of alternative suggestions I'll move the article to three-dimensional rotation operator, fix inbound links from other articles, redirect the former title to rotation operator, a dab page, and edit this dab with addition of the rotation (mathematics) choice. Incnis Mrsi (talk) 16:19, 5 March 2014 (UTC)

Let's not forget Rotation formalisms in three dimensions. Personally I think there should be one article on rotations in three dimensions, rather than several that treat basically the same topic with slightly different emphasis. S?awomir Bia?y (talk) 19:02, 5 March 2014 (UTC)

I never forget about "rotation formalisms...". But may I move the article in question, in the absence of an instant solution, before doing anything else? Otherwise one can forget to fix the erroneous Rotation operator (vector space) (edit | talk | history | links | watch | logs) title and such invalid links will pollute Wikipedia further. Incnis Mrsi (talk) 12:34, 9 March 2014 (UTC)

I think a merge would be a better solution than having two essentially identical articles, whatever their titles happen to be. S?awomir Bia?y (talk) 13:10, 9 March 2014 (UTC)

Mirror symmetry

Hello,

I just wanted to let everyone know that the article on mirror symmetry (string theory) is currently a featured article candidate. It would be great if some of the mathematicians on Wikipedia could review the article. If you're interested, you can leave a comment on this page. Instructions for reviewers can be found here. Thanks. Polytope24 (talk) 17:28, 9 March 2014 (UTC)

Request for help

Hey, WikiProject Math,
I just reverted some edits at Curve that didn't look constructive. But this article doesn't get a lot of views and I'd like it if someone who had more familiarity with geometry than me (i.e. my sophomore year in high school) could confirm that these deletions of text were not an improvement. Thanks! Liz ^{Read! Talk!} 22:58, 9 March 2014 (UTC)

An edit like [6] seems like an improvement to me. -- Taku (talk) 12:41, 10 March 2014 (UTC)

Cramér's conjecture

Marek Wolf (talk · contribs) and a set of anonymous editors (or one editor acting from multiple IP addresses) have been trying to add a 2014 paper published by Marek Wolf, and a conjecture named by Wolf after himself, to the Cramér's conjecture article. Deltahedron (talk · contribs) and I have reverted for now but more eyes would be helpful. There is also a discussion of this issue on the article talk page for which additional contributions would be welcome. --David Eppstein (talk) 23:14, 1 March 2014 (UTC)

I note that similar material appears in Prime gap. There is also a Marek Wolf-generated figure in each article. --Mark viking (talk) 23:32, 1 March 2014 (UTC)

And in Cousin prime. YohanN7 (talk) 01:38, 2 March 2014 (UTC)

There is also a mention of Wolf in Riesz_function, which someone who knows something about the subject should assess for relevance. --JBL (talk) 02:04, 2 March 2014 (UTC)

I am far from an expert in the subject but (without an error term) the equality asserted in this mention looks nonsensical. --David Eppstein (talk) 02:22, 2 March 2014 (UTC)

Indeed, and on reading the paper by Wolf it appears that the RHS is indeed the leading term in a series for the Riesz function, not the function itself. Deltahedron (talk) 07:41, 2 March 2014 (UTC)

I've reported the IP that has been the source of most of the recent edits for edit-warring. --JBL (talk) 01:49, 2 March 2014 (UTC)

In spite of all this, I do hope that it will be possible to explain the local customs to User:Marek Wolf: the best possible outcome would be to have him join as a constructive editor contributing content in his field of expertise. Deltahedron (talk) 09:57, 2 March 2014 (UTC)

New ip user around: 46.205.82.65 YohanN7 (talk) 14:36, 2 March 2014 (UTC)

User:Marek Wolf has now been blocked for a week. I do not think that was the best way of dealing with this situation. Deltahedron (talk) 17:44, 2 March 2014 (UTC)

An ip user is at it again. This time at Prime gap. YohanN7 (talk) 21:58, 4 March 2014 (UTC)

The changes at prime gap [7] are incorrect, as can be easily verified. I have not read the original Wolf paper (the link in the article is dead) to see if the formula given there is also incorrect. (Clearly, g(p) ~ log^2 p is too strong: g(p) < 7*10^7 infinitely often as Zhang proved.) The changes at Cramér's conjecture refer to the maximal gap G(p) and so look fine mathematically (it's just an issue of Wikipedia notability). CRGreathouse (t | c) 22:42, 10 March 2014 (UTC)

A draft at AfC needs help

Please take a look at WT:Articles for creation/Shreni Integration and help get it into shape - if it is a notable topic of course. Roger (Dodger67) (talk) 19:09, 10 March 2014 (UTC)

Google provides no evidence of this term ever being used for anything. --JBL (talk) 19:59, 10 March 2014 (UTC)

Looking at the content, it's just some sort of iterated integration by parts. I don't think there's any chance this is notable. --JBL (talk) 20:03, 10 March 2014 (UTC)

It seems like WP:OR to me. There is at least no indication that this is a notable series under the name "shreni series" or "shreni integration". S?awomir Bia?y (talk) 22:43, 10 March 2014 (UTC)

Invitation to Participate in a User Study - Final Reminder

Would you be interested in participating in a user study of a new tool to support editor involvement in WikiProjects? We are a team at the University of Washington studying methods for finding collaborators within WikiProjects, and we are looking for volunteers to evaluate a new visual exploration tool for Wikipedia. Given your interest in this Wikiproject, we would welcome your participation in our study. To participate, you will be given access to our new visualization tool and will interact with us via Google Hangout so that we can solicit your thoughts about the tool. To use Google Hangout, you will need a laptop/desktop, a web camera, and a speaker for video communication during the study. We will provide you with an Amazon gift card in appreciation of your time and participation. For more information about this study, please visit our wiki page (http://meta.wikimedia.org/wiki/Research:Finding_a_Collaborator). If you would like to participate in our user study, please send me a message at Wkmaster (talk) 15:32, 11 March 2014 (UTC).

I'd guess video communication would also require a microphone. I don't have a webcam; otherwise I might be curious about what this is. Michael Hardy (talk) 16:51, 11 March 2014 (UTC)

Distributive property of division

Since ${\frac {a+b}{c}}={\frac {a}{c}}+{\frac {b}{c}}$ ,

why isn't the property mentioned in the Division article? Hill Crest's WikiLaser! (BOOM!) 04:35, 13 March 2014 (UTC)

Never ask why something has not been done in Wikipedia! Just do it yourself! JRSpriggs (talk) 07:32, 13 March 2014 (UTC)

It probably wasn't done because it isn't explicitly the distributive property of division. It follows directly from the distributive property of multiplication. However, it can reasonably be mentioned in division. Robert McClenon (talk) 01:03, 16 March 2014 (UTC)

Indexes in sums

There is a discussion at talk:volume fraction about using or not using different indexes in a fraction where the numerator V_i is included in a sum that appears in the denominator. Some mathematical feedback would be useful.--188.26.22.131 (talk) 10:23, 17 March 2014 (UTC)

intersection of sin x and cos x in a graph

where do the intersection value of x and y cross each other ? I can see the value of x in radian is at $\pi /4$ but y is around ${\frac {1}{14}}$ 70.53.125.83 (talk) 21:17, 16 March 2014 (UTC) Never mind it's intersection is at ${\frac {1}{\sqrt {2}}}$ or $\sin {45}and\cos {45}$

Consider

\sin ^{2}(x)=1-\cos ^{2}(x)

. This will reduce to finding special values of sine or cosine. Some better places to ask these questions are on the talk page, Wikipedia:Reference desk/Mathematics, or a dedicated Q&A like math.stackexchange. ? LokiClock (talk) 01:46, 17 March 2014 (UTC)

Please: Write

\sin ^{2}(x)=1-\cos ^{2}(x)

, not

sin^{2}(x)=1-cos^{2}(x)

. TeX and stripped-down TeX such as that used here were designed well. Michael Hardy (talk) 17:44, 18 March 2014 (UTC)

I do in general. ? LokiClock (talk) 14:08, 19 March 2014 (UTC)

If you really want to annoy Michael Hardy,

{\mbox{do this}}

. :-D S?awomir Bia?y (talk) 22:18, 19 March 2014 (UTC)

@70.53.125.83 : The proper place for questions like this is Wikipedia:Reference_desk/Mathematics. This page is for discussion of the creation, maintenance, and improvement of Wikipedia's coverage of mathematics. Michael Hardy (talk) 17:46, 18 March 2014 (UTC)

Elliptic curve primality

I had merged Elliptic curve primality testing and Elliptic curve primality proving and after merging I moved the Elliptic curve primality proving to a new page called Elliptic curve primality. Had I done anything wrong.Please leave a message regarding this to my talk page.--Skr15081997 (talk) 14:14, 21 March 2014 (UTC)

No new articles on the current activity page

For several days there have been no new articles at Wikipedia:WikiProject_Mathematics/Current_activity. I've sent emails to Oleg Alexandrove and to Jitse's bot. Am I the only person who notices this? Michael Hardy (talk) 19:35, 21 March 2014 (UTC)

You're certainly not the only person who notices, and thanks for taking some action about it. --David Eppstein (talk) 19:59, 21 March 2014 (UTC)

Maybe wikipedia is finally finished? --Salix alba (talk): 21:59, 21 March 2014 (UTC)

Not even close. -- Taku (talk) 23:51, 21 March 2014 (UTC)

I can think of one mathematics article that's not there yet and should be. It will take some work . . . . . Michael Hardy (talk) 15:08, 22 March 2014 (UTC)

Rather more than one. Deltahedron (talk) 17:05, 22 March 2014 (UTC)

Oleg has told me the problem is now fixed.

We're hanging by a thread: Jitse Niesen runs the bot that updates the current activities page; Oleg Alexandrov runs the bot that maintains the list of mathematics articles, which Jitse's bot relies on for the information one new articles; and I am the only person who points out to them when one of the bots is not working. For more than five years I've been the only one who does that (unless there are some isolated excecptions). If the three of us were assassinated (or maybe any one of the three) the Universe would collapse. Michael Hardy (talk) 15:06, 22 March 2014 (UTC)

Semi-invariants of quivers

There is a new article called Semi-invariants of quivers. Should it be changed to Semi-invariant of a quiver or the like? Michael Hardy (talk) 18:22, 26 March 2014 (UTC)

I do not believe anymore that Wikimedia can ever discourage certain kind of new users from dumping their blurry waste to Commons. Incnis Mrsi (talk) 18:41, 26 March 2014 (UTC)

Issues of blurry waste aside, I agree that the article should be moved to Semi-invariant of a quiver in keeping with WP:SINGULAR. --Mark viking (talk) 19:21, 26 March 2014 (UTC)

AfC submission - 25/03

User:The tree stump/Fingerprint Database for Theorems. FoCuSandLeArN (talk) 11:45, 25 March 2014 (UTC)

This submission is based entirely on an AMS Notices article by Billey and Tenner (the article's first reference). The Billey and Tenner article is a primary source for the concept of a fingerprint database for theorems, because they define such databases and propose that the mathematics community make a systematic effort to construct them. The article linked above presents no evidence that this idea is notable. While Billey and Tenner present several examples of such databases (e.g., the OEIS), in that capacity they are serving as secondary sources for the notability of those examples. They can't be a secondary source for or establish notability of a concept that they introduce. Ozob (talk) 14:19, 25 March 2014 (UTC)

I like the idea of such a database very much, but at this point it seems to me premature to have an article on it given the lack of secondary sources. S?awomir Bia?y (talk) 14:02, 27 March 2014 (UTC)

Links to Erd?s-Nicolas number

Nothing currently links to Erd?s-Nicolas number except the List of things named after Paul Erd?s. Michael Hardy (talk) 17:43, 27 March 2014 (UTC)

Is this draft about a notable topic?

Wikipedia talk:Articles for creation/Benacerraf's identification problem - I have asked WikiProject Philosophy the same question. Roger (Dodger67) (talk) 13:27, 28 March 2014 (UTC)

It's about philosophical questions that most mathematicians pay little attention to, so I'm not sure anyone here will be able to help. I can say that at least the mathematical part is not nonsense (unlike some mathematical philosophy). Ozob (talk) 14:07, 28 March 2014 (UTC)

AfC submission - 26/03

Is there anything salvageable from Wikipedia talk:Articles for creation/Sieve of Nicholls? FoCuSandLeArN (talk) 02:29, 27 March 2014 (UTC)

No. This is clearly pure WP:OR, someone attempting to publish their own work on Wikipedia. Bill Cherowitzo (talk) 03:41, 27 March 2014 (UTC)

I agree -- this is exactly what I was about to write. --David Eppstein (talk) 03:47, 27 March 2014 (UTC)

The OR is miles deep. Anything worth salvaging would be too hard to find to make it worthwhile. S?awomir Bia?y (talk) 14:09, 27 March 2014 (UTC)

It appears to me that Wikipedia talk:Articles for creation/Sieve of Nicholls is _not_ an attempt to flout the policy against original research, but simply a result of unawareness of the existence of that policy. Michael Hardy (talk) 23:01, 29 March 2014 (UTC)

Cheers for that. What about Wikipedia talk:Articles for creation/Mean log deviation? FoCuSandLeArN (talk) 14:44, 27 March 2014 (UTC)

Who is a mathematician?

There appears to be a disagreement on Vi Hart over whether she should be categorized as a mathematician. Additional opinions welcome. --David Eppstein (talk) 05:48, 31 March 2014 (UTC)

This has now expanded to a debate on what an Amature mathematician is and to the creation of Category:Amateur mathematicians. Which is now listed at Wikipedia:Categories for discussion/Log/2014 March 31#Category:Amateur mathematicians. --Salix alba (talk): 09:56, 31 March 2014 (UTC)

I am working on many things in this WikiProject. Feedback and suggestions please?

Recently, I made my first big edit to Triangular number, in which I derive the entire formula to find the triangular roots of a number, and explain the form of the second triangular root.

I am asking for feedback and advice for editing these types of articles. Hill Crest's WikiLaser! (BOOM!) 22:59, 22 March 2014 (UTC)

Notice that Pairing function makes use of triangle numbers and triangular roots. JRSpriggs (talk) 00:40, 23 March 2014 (UTC)

Another big edit readied up at Heptagonal number. Hill Crest's WikiLaser! (BOOM!) 03:44, 23 March 2014 (UTC)

One hint: Indent equations using a colon. YohanN7 (talk) 09:59, 23 March 2014 (UTC)

Okay, one suggestion. If you are not a programmer, then forget about the asterisk (*) symbol until you learned about one of few things in higher mathematics that actually use it in the notation. Read the multiplication article to learn how to denote the multiplication. You can also consult a MoS. Incnis Mrsi (talk) 11:26, 23 March 2014 (UTC)

Correcting the symbols right now. Hill Crest's WikiLaser! (BOOM!) 14:09, 23 March 2014 (UTC)

Perhaps more importantly -- I assume you derived the formula entirely by yourself? If so, nice work, but unless you can point to an independent reliable source that can be used to verify your material, it is original research and we just cannot use that. Deltahedron (talk) 12:36, 23 March 2014 (UTC)

The derivation becomes trivial when one understands the quadratic formula. And also, where did all those tests on the polygonal number pages come from? Hill Crest's WikiLaser! (BOOM!) 14:08, 23 March 2014 (UTC)

Very detailed derivations are not generally included in articles. Because the formulae are trivial consequences of the quadratic formula, we should say just that. S?awomir Bia?y (talk) 14:13, 23 March 2014 (UTC)

~~If you don't like how I edited, go ahead and change them.~~ Hill Crest's WikiLaser! (BOOM!) 14:16, 23 March 2014 (UTC)

You asked for suggestions and feedback. You received some very good advice, so there is no need to feel or sound bitter. YohanN7 (talk) 15:17, 23 March 2014 (UTC)

Ok, striked out that comment.Hill Crest's WikiLaser! (BOOM!) 20:52, 31 March 2014 (UTC)

Not to forget, a gnome that appears in the article with a tiny correction amidst a series of major improvements by another editor can be an annoying factor because of edit conflicts. Of course, I could wipe out the asterisk heresy myself as I did hundreds of times. But after Hillcrest98 asked for suggestions, it seems that a direct editing of articles by other users is not warranted (sorry, my English is sometimes awkward). Incnis Mrsi (talk) 15:50, 23 March 2014 (UTC)

In sequences like Padovan sequence and Perrin number, should we put the index numbers of the sequence in parentheses or subscripts? Hill Crest's WikiLaser! (BOOM!) 20:52, 31 March 2014 (UTC)

Apr 2014

More female math editors?

At a math conference this weekend I was talking to a past president of the Association for Women in Mathematics about a recent NPR report on the Smithsonian's Edit-A-Thon that was intended to increase the number of female editors in Wikipedia. I told her that I would broach the more specific problem of the lack of female math editors here.

The general problem of the lack of female editors is compounded for us because there are relatively fewer females who feel confident enough to tackle math articles. I think that it is important for this project to try to improve the picture. Due to anonymous editing, we really can't "target" female editors, but we can, with a little practice, make ourselves more inviting to newer editors in the hope that female editors would be more attracted to a less hostile environment.

Here are a couple of suggestions:

When you have made changes (or reverts) to the edits of a "new-ish" editor, instead of packing the reason into a curt edit summary, try being a little more expressive on a talk page (the user's or the article's, depending on circumstances), indicating why you felt that the changes were necessary.
Make sure that you add the reasons for putting up a maintenance tag on the article's talk page.
Give a more personalized welcome on a new editor's talk page. Something a bit friendlier than the standard <<Hello - Welcome - Here are the Rules>> templates that are available.
Perhaps someone could develop a template that would invite a new editor to consider joining this WikiProject, to be used when we see someone editing math articles.

I am sure that there are other things that we can do, both individually and collectively, to encourage and foster good editing in a non-threatening environment. Bill Cherowitzo (talk) 19:02, 31 March 2014 (UTC)

Reminding folks to be kind to new editors is good advice for any gender. We have the invitation template {{MathInvitation}}, but I do not know if it is used much. --Mark viking (talk) 21:07, 31 March 2014 (UTC)

I wasn't aware of the existence of that template, but will start using it. Deltahedron (talk) 06:28, 1 April 2014 (UTC)

Thanks, I also wasn't aware of that template. It is a bit cut and dry, I was hoping for something a little more inviting. I won't mess with this template since it is transcluded in the {{MathWelcome}} templates, but I'll think about some alternate wording. Bill Cherowitzo (talk) 16:31, 1 April 2014 (UTC)

I think that the approach of making the initial experience for new editors more encouraging is sensible, as a lot of value is added by editors across the spectrum. Even though I'm no longer entirely a novice editor, I occasionally find I need a thick skin, and also still occasionally regret my own abruptness. WP is a nice context for limiting the bias/polarization on any categorization, and would not like to see this becoming a focus here, as it would subtly undermine the principles. One should also take care not to address symptoms rather than a problem. For example, if relatively few women have mathematical interest and involvement, we should expect only a roughly proportionate representation in endeavors such as editing of math articles. If there are factors acting to discourage a group more than their natural inclination, these factors should be identified and addressed directly, rather than compensatory measures being adopted to "fix the statistics". On friendly templates, would it make sense to highlight that contributions according to ability and skill have value here, regardless of the degree of skill? --Quondum 18:15, 1 April 2014 (UTC)

The meta-wiki page, Proposals for more female editors, might also have suggestions that will help this project. RockMagnetist (talk) 18:40, 1 April 2014 (UTC)

WP:NPOV suggestion.

Does anyone have a suggestion for an article that would be better as an example of "Some articles don't necessarily have NPOV disputes" than Heptagonal antiprismatic prism? Naraht (talk) 14:31, 1 April 2014? (UTC)

Gamma function? -- Taku (talk) 16:59, 1 April 2014 (UTC)

Most articles don't have NPOV disputes. What are you hoping to do with the example? RockMagnetist (talk) 17:17, 1 April 2014 (UTC)

I've seen arguments on some articles that there is a POV on everything and as such writing an article from an NPOV is actually impossible. I thought that an article on a mathematical polytope, while people something that people couldn't touch, would qualify.Naraht (talk) 10:12, 2 April 2014 (UTC)

Sometimes mathematics articles do have POV disputes, though it's not common. I like the suggestion of gamma function, because it's a very well-developed article on an important topic and doesn't have any POV disputes that I'm aware of. If you want a non-mathematical example, you might try an asteroid like 3753 Cruithne; it's hard to get worked up over a chunk of rock. Ozob (talk) 14:16, 2 April 2014 (UTC)

(edit conflict) I agree that the description of a mathematical object, in the framework of a fixed mathematical theory is generally not really subject to POV. However, to be encyclopedic a mathematical article must not be restricted to the description of an object or a theory. It should explain why this object or theory has been introduced and what are its usage and applications. In Heptagonal antiprismatic prism for example, the description of this polytope is not subject to POV, even if it could be done with a more accessible formulation. But its notability is questionable, and the number of mathematicians that have encountered it and know its name is certainly very low. My POV, is that it does not deserve a specific article, and that its description would better placed in an article Polytopes that have received a name. This is a point of view. On the other hand, Gamma function is much closer to a NPOV article: The gamma function is known by all mathematicians and is used by many of them. Thus its importance may not been disputed, nor the description of its properties. However, there are several equivalent ways to define it (definite integral and analytic continuation, functional equation, differential equation, ...). The POV of the editors of this article was to choose the first definition, and to describe the other ones as properties. Other choices would be also valuable. D.Lazard (talk) 14:22, 2 April 2014 (UTC)

I presume that the statement "there is a POV on everything" was made after an article has been tagged for having a POV. That's just a cop-out. You should make sure that the tag is associated with a discussion of some specific concerns on the talk page (see the usage notes at Template:POV). If they do, those concerns have to be addressed. If not, the tag can be removed. Either way, the status of Heptagonal antiprismatic prism or Gamma function is irrelevant. Unless the dispute is over a math article, this isn't the place to discuss it. RockMagnetist (talk) 15:24, 2 April 2014 (UTC)

AfC submission - 02/04

Draft:István Fenyó. FoCuSandLeArN (talk) 15:59, 2 April 2014 (UTC)

Multivariate holomorphic functions

The definition seems natural, but what are the multivariate Cauchy-Riemann equations? Also, the requirement of square integrability seems very unnatural to me because it's not a requirement of the univariate case. Just for example, the holomorphic function from $f:\mathbf {C} \to \mathbf {C} f(z)=z$ does not meet that condition in the univariate case (integrals of its square over the entire complex plane and the entire real line are both infinite).--Jasper Deng (talk) 02:52, 3 April 2014 (UTC)

It says "locally square-integrable" (underscore added). So the integral is not over the entire complex plane. JRSpriggs (talk) 04:05, 3 April 2014 (UTC)

One could assume that it's a sufficient condition for holomorphicness, but I can't see why it should be a necessary' condition.--Jasper Deng (talk) 04:32, 3 April 2014 (UTC)

I do not know. JRSpriggs (talk) 08:17, 3 April 2014 (UTC)

I think I have a partial answer to this quandary. Ohsawa's Analysis of Several Complex Variables opens with a proof that holomorphic functions are weak solutions to the Cauchy-Riemann equations; but, he says, "to keep our argument as simple as possible" he restricts to locally square integrable functions. I'm guessing Ohsawa was the original source for this claim and that this hypothesis isn't necessary. The question is what the right hypothesis should be. Probably the theorem holds for any distributional solution whatsoever, but I don't know enough about regularity of solutions to elliptic PDEs to say that with confidence. Ozob (talk) 15:09, 3 April 2014 (UTC)

Hörmander does the L^2 theory, but I don't have a copy on hand to check. S?awomir Bia?y (talk) 15:21, 3 April 2014 (UTC)

(Top of my head). Let f be a (Schwarz) distribution on an open subset

U\subset \mathbb {C} ^{n}

. Suppose f satisfies multivariable CR equations; that is,

\partial f/\partial {\overline {z}}_{j}=0,j=1,\dots ,n.

(A fancier way is to say,

{\overline {\partial }}f=0.

) Then f also satisfies the Laplace equation; thus, by elliptic regularity, it is smooth (and everything reduces to the classical setting.) Of course, f is uniquely defined up to measure-zero set. -- Taku (talk) 18:17, 3 April 2014 (UTC)

Hilbert spaces in quantum mechanics

Hi!

I'd appreciate if a mathematician could have a look at Talk:Wave function#Inner product (again). I have had a content dispute with myself. The thing is that I'd like to see the inner product defined on solution spaces of the Schrödinger equation be the right one to yield a Hilbert space. Alternatively, given an inner product, find the "right space" of functions (if it exists) to apply it to to yield a Hilbert space.

In particular, does my last post there (as of now) have an element of truth? YohanN7 (talk) 14:10, 4 April 2014 (UTC)

Should display equations be centered?

Temporary local fix

As a temporary measure, until the extension if fixed, a single line of CSS in Common.css will force MathJax to left-align display fomulae. Any objections? -- Edokter (talk) -- 17:25, 5 April 2014 (UTC)

Since there's an outstanding patch to fix the problem, I think it's more important to get the patch reviewed and deployed than to make a temporary fix. But I'm not going to object to a temporary fix, either. Ozob (talk) 00:13, 6 April 2014 (UTC)

There is a big problem get code review for anything maths related and this fix in particular so it may take a while. A local fix seems a sensible option.--Salix alba (talk): 00:35, 6 April 2014 (UTC)

That is a massive patch which does not just deal with just centering. Something that needs to be tested on test.wikipedia.org first. I'll place the fix in the mean time. -- Edokter (talk) -- 01:12, 6 April 2014 (UTC)

Changes to Math extension

We landed fixes for bugzilla:63016, bugzilla:63574 and bugzilla:61051 this weekend and bugzilla:36060 should hopefully all be merged before tuesday. That means that these these changes will be live on english wikipedia in about 1,5 to 2 weeks. It will be appreciated if you can do some more testing on beta labs. Note that this site is considered not secure, so use a different password if you want to test MathJax. --TheDJ (talk o contribs) 22:14, 6 April 2014 (UTC)

Thanks for the update. The fix to use local fonts instead of having to download them is especially good news as it should significantly speed rendering. I see that these fixes also include removing centering for displayed equations, discussed above, and something about color within equations. --David Eppstein (talk) 22:35, 6 April 2014 (UTC)

AfC submission - 08/04

I've posted this in the computer science WikiProject, but it looks defunct. Wikipedia talk:Articles for creation/Microscale and Macroscale Models. FoCuSandLeArN (talk) 19:29, 8 April 2014 (UTC)

Hsu-Robbins-Erd?s theorem

Only one page links to the new article Hsu-Robbins-Erd?s theorem. Michael Hardy (talk) 03:39, 9 April 2014 (UTC)

Mathematics defaulters

In mathemics, how would the defaulters be retrieved, example when the wikipedia's edits in English is: 4,488,884. We have many attempt and many deleted, all of them are wikipedians, yet, not recorded among the 4,488,884, then, how would these defaulters be retrieved, these defaulters are wikipedians regardless of trivial, it generally mean that wikipedians are miscalculated in the world of mathematics, if it's only, as example: 4,488,884 are the English edits? am Jesmion 41.206.11.63 (talk) 10:10, 9 April 2014 (UTC)

Don't think I understand two consecutive words of this. YohanN7 (talk) 11:55, 9 April 2014 (UTC)

Main Page currently says "4,489,960 articles in English". It was probably 4,488,884 when you posted. I don't know what you mean by defaulters but I suspect your question is about what is included in the count. See Wikipedia:What is an article?#Lists of articles and statistics. Redirects and deleted pages don't count. Disambiguation pages do count. The count is for the English Wikipedia, i.e. the website at http://en.wikipedia.org where "en" is the language code for English. The count is made automatically and it's not checked whether the pages are actually in English. PrimeHunter (talk) 23:54, 10 April 2014 (UTC)

This User:Jesmion? WhatamIdoing (talk) 16:12, 11 April 2014 (UTC)

Style

There is a discussion on the perennial topic of the level of mathematical sophistication appropriate for mathematics articles at Wikipedia_talk:Manual_of_Style/Mathematics#Rewrite, arising out of a discussion at Talk:Waring's_problem#Copy_Editing. Deltahedron (talk) 06:37, 11 April 2014 (UTC)

Related drama now at Wikipedia:Administrators'_noticeboard/Incidents#Please_Temp-Block_Dicklyon_for_Disruptive_Reversions. Deltahedron (talk) 15:58, 12 April 2014 (UTC)

Ramanujan-Sato series

This new article could use some 'cats'. Bearian (talk) 21:57, 10 April 2014 (UTC)

meow? YohanN7 (talk) 22:02, 10 April 2014 (UTC)

Category:mathematical series? -- Taku (talk) 22:05, 10 April 2014 (UTC)

Added. --Mark viking (talk) 16:01, 12 April 2014 (UTC)

Category for discussion

Please see Category:0 hyperbolic volume knots and links and Wikipedia:Categories for discussion/Log/2014 April 17#Category:0 hyperbolic volume knots and links. The discussion is about how to name the category, not whether it should be kept as a category. --David Eppstein (talk) 21:18, 17 April 2014 (UTC)

Additive polynomial and Linearised polynomial

These articles seem to overlap sufficiently that a merger could be appropriate? Deltahedron (talk) 21:15, 18 April 2014 (UTC)

User:Frivolous Consultant/sandbox

Dear mathematicians: This old Afc submission about something called "Tessellation conglomerate" will soon be deleted as a stale draft. Is there anything here that should be saved? --Anne Delong (talk) 02:19, 20 April 2014 (UTC)

There is probably room for an article on the same general topic (counting the number of copies of some shape within a larger pattern) but that draft looks pretty hopeless to me. --David Eppstein (talk) 02:33, 20 April 2014 (UTC)

Okay, thanks. I will let it go. --Anne Delong (talk) 02:57, 20 April 2014 (UTC)

AfC submission - 17/04

This is another one that doesn't completely fall under the Mathematical domain, but it's been lingering in the queue for too long. Wikipedia talk:Articles for creation/Exponential Search. Thanks, FoCuSandLeArN (talk) 21:08, 17 April 2014 (UTC)

I'd say this one looks credible (though I didn't read it thoroughly). Is there no Wikiproject for Computer Science? They'd be able to tell (at least if it exists). YohanN7 (talk) 05:39, 21 April 2014 (UTC)

There is such a project: Wikipedia talk:WikiProject Computer science. I have it watchlisted, but it's not very active compared to this one. --David Eppstein (talk) 05:54, 21 April 2014 (UTC)

Also Draft:Cell-probe model. FoCuSandLeArN (talk) 23:48, 20 April 2014 (UTC)

J-structure

J-structures are an alternative approach to developing Jordan algebras proposed by T. A. Springer in a 1973 book. There is a page J-structure which currently redirects to Jordan algebra, but the latter article does not mention J-structures at all. Curiously, there is an article hidden underneath the redirect [11] which was overwritten by Mathsci on the grounds that it had been written by a banned user [12]. The article itself seems tolerable but I prefer to get consensus before restoring anything by a banned user per Wikipedia:Banning policy. Deltahedron (talk) 21:08, 18 April 2014 (UTC)

Even banned editors can make good edits. Given the ban, Mathsci was right to revert the edit. But if you have independently reviewed the material and it looks sensible and the source holds up (I'll note the book is online at Google books [13]) then I don't see why the prose could not be used to start an article on the subject. --Mark viking (talk) 21:40, 18 April 2014 (UTC)

How funny, the "banner" of the banned editor edits is himself banned. Therefore, per WP:ZAUFOIHWCNA, the overwrite must be reverted. YohanN7 (talk) 21:52, 18 April 2014 (UTC)

It's just a typo. The correct link is Wikipedia:Sockpuppet investigations/Echigo mole. --David Eppstein (talk) 22:43, 18 April 2014 (UTC)

What typo? The article was turned into a redirect by Mathsci, and Mathsci is now banned. But I'm with Mark Viking: if the material by itself is found worthy to return, no matter who wrote or removed it, then it should. -- HHHIPPO 09:08, 19 April 2014 (UTC)

Sorry, I misinterpreted an earlier comment. The edit summary linked to by Deltahedron contains a typo in its wikilink, making it hard to find the details of the banned user. --David Eppstein (talk) 20:22, 19 April 2014 (UTC)

I would be rather wary of restoring anything by this banned user. There was a rather bizarre case a few years ago: I cannot remember the exact details, but it involved him harassing another editor for several years by creating poor but plausible cut-and-paste articles in areas the other editor was working on, for which he was eventually banned. I had a quick look at the deleted article, and it is part of a similar pattern: it is a jumble of close paraphrases of assorted sentences from Springer's book (so in any case may be a copyright infringement). My advice is that it will probably be less trouble in the long run to rewrite the article from scratch. r.e.b. (talk) 18:50, 19 April 2014 (UTC)

Thanks for that -- I'll work on a copy to eliminate those problems. Deltahedron (talk) 21:30, 21 April 2014 (UTC)

Is this real or a hoax?

At the risk of advertising my mathematical illiteracy, could someone take a glance at Redundant proof just be sure that it is not someone's idea of a joke? It popped up on my NPP queue and frankly if it were written in ancient Aramaic I'd have had a better shot at grasping it. Thanks... -Ad Orientem (talk) 22:23, 7 April 2014 (UTC)

I don't know anything about it so I can't be sure, but it doesn't push my "hoax" button. I suspect it's the work of a new editor adding stuff on proof compression, whatever that is exactly, and scattering it over several articles without giving sufficient context. Will need cleanup. --Trovatore (talk) 22:46, 7 April 2014 (UTC)

The sole WP:RS listed in the article has only been cited 8 times (fide google scholar). Not sure this clears the notability hurdle. Lesser Cartographies (talk) 23:08, 7 April 2014 (UTC)

Well, that could likely be addressed by consolidating the articles. I think eight cites on a highly technical topic is at least borderline, at least if they're high-quality cites, but probably better if the content isn't scattered all over the place. --Trovatore (talk) 23:41, 7 April 2014 (UTC)

Ah, good to know. In compsci systems work, my rule of thumb is >100 cites before we can hang an article on a publication. That's highly domain-specific, of course; thanks for the reminder. Lesser Cartographies (talk) 01:37, 8 April 2014 (UTC)

Redundant proof is not a joke; automated theorem provers can generate sub-proofs that are redundant with the main proof or with other sub-proofs and elimination of redundancies can be important in applications like proof-carrying code. But the editor, in addition to creating a number of articles, (Redundant proof, LowerUnits, and Resolution inference), seems to be refspamming the Fontaine, et. al. ref, or at least it seems unlikely that this one ref is the best one for several different articles. --Mark viking (talk) 00:33, 8 April 2014 (UTC)

OK it looks at least somewhat legit. As for the other details, I will leave that to the experts on this forum. Thanks for the help! -Ad Orientem (talk) 00:46, 8 April 2014 (UTC)

It looks to me more like it should be a term within some other topic rather than a topic in itself and only split out if there was more on it. Wikipedia isn't a dictionary, though we can use redirects for terms within a topic so it does actually have a dictionary aspect. Dmcq (talk) 08:24, 8 April 2014 (UTC)

As far as I understand, this article is about a specific (among several) notion of formal proofs (which one?). It uses, without any definition, a non-standard notation (

\odot

), and does not explain it relationship with the standard (in operational semantics) notation of the example (I have not found where this notation is defined in WP. On the other hand, removing redundancies in proofs is a specific instance of rewriting. All this being considered, the special case considered here is particularly minor and non-notable, and I strongly support the deletion of this article. D.Lazard (talk) 11:35, 8 April 2014 (UTC)

[Sorry about the delay]. Doesn't appear to be a hoax (although I could be wrong), but none of the articles mentioned above are standard usage. LowerUnits should be deleted entirely; redundant proof redirected to a paragraph in proof compression, if an actual use can be found; and resolution inference be redirected to resolution (logic) (with the identical section removed as being too detailed. If I have time, I'll replace the Proof compression article with something actually referenced to usable references. -- Arthur Rubin (talk) 20:22, 21 April 2014 (UTC)

The notability would not be as a concept (a special case of string rewriting) but a problem or research area. It might be placed under proof compression, but that can suggest a focus on efficiency of the proof, making it as small as possible, whereas finding or eliminating the generation of redundant subproofs is a relevant concern in producing human-readable proofs. As with any other program, an automated proof's lucidity can be compromised by optimization. ? LokiClock (talk) 00:17, 23 April 2014 (UTC)

Capitalization of theorem titles

I started a conversation at Wikipedia Village Pump (misc):Capitalization of theorem titles before it occurred to me it would probably be more appropriate here. I'd appreciate input. --Yoda of Borg (?) 04:00, 24 April 2014 (UTC)

TeX not rendered

Is TeX code failing to get rendered on Wikipedia today, or is it just me? Michael Hardy (talk) 18:39, 17 April 2014 (UTC)

You do not appear to be alone. Bill Cherowitzo (talk) 19:27, 17 April 2014 (UTC)

Yes, I'm seeing the source code in all its glory. RockMagnetist (talk) 19:57, 17 April 2014 (UTC)

I found them rendered, but as PNG, even though I used to have MathJax enabled. So I checked my preferences and found them set to "PNG" rather than "leave as TeX" and "MathJax" unchecked. The combination of "leave as TeX" and "MathJax" checked seems to give the status ante for me. -- HHHIPPO 20:23, 17 April 2014 (UTC)

This is due to bugzilla:63915. All users who used to have mathjax enabled, need to enable it again manually atm. --TheDJ (talk o contribs) 20:59, 17 April 2014 (UTC)

@TheDJ: I am getting inconsistent results with MathJax enabled. Gamma function looks fine, but most others (e.g., Calculus) are full of [Math processing error]). RockMagnetist (talk) 21:39, 17 April 2014 (UTC)

Do you have more information ? browser, os, nageh version/core version, other installed extensions ? --TheDJ (talk o contribs) 06:25, 18 April 2014 (UTC)

@TheDJ: Mac OS 10.9.2, latest versions of Chrome, Safari and Firefox. I can't make the javascript javascript:alert(mathJax.version) work on any of them. As for extensions, do you mean Wikipedia gadgets or something else? RockMagnetist (talk) 16:37, 18 April 2014 (UTC)

I advise everyone to check: "Leave it as TeX" and the "MathJax" option. The "PNG" + "MathJax" option will take some time before it is fully working. --TheDJ (talk o contribs) 06:33, 18 April 2014 (UTC)

Isn't it a bit complex having a radio button and a checkbox in the preferences. When I reset my preferences in a rush, I didn't initially notice the subtle difference. Wouldn't it be simpler just to have a three-way radio button PNG/tex/MathJax. --Salix alba (talk): 07:21, 18 April 2014 (UTC)

The way the options are displayd is a logical fallacy; only one should be enabled. PNG + MathJax result in images loaded first before MathJax kicks in... what a waste of bandwidth! -- Edokter (talk) -- 12:27, 18 April 2014 (UTC)

No, it's on purpose, it will allow us to come closer to the point where mathjax is independent from how we serve the content. It's all with the long term vision of png reliable rendering, searchable svg math, mathjax/mathoid rendering for the pdf renderer etc etc. --TheDJ (talk o contribs) 14:00, 18 April 2014 (UTC)

I appreciate that the long term view is an important one, but I think there is a lesson to be learned from the fiasco of the broken align environment that the short term view cannot be ignored. If in the short run readers see something they don't expect, then there's a good chance that they will change the article to something that is actually worse when everything is finally working properly. S?awomir Bia?y (talk) 14:44, 18 April 2014 (UTC)

As a matter of interest, where do we go to see the official long-term view? Deltahedron (talk) 16:11, 18 April 2014 (UTC)
- Since support for Math is a pure volunteer driven effort, there is nothing that you could call official. And there are discussions on the wikitech-l mailing list every now and then. --TheDJ (talk o contribs) 19:02, 18 April 2014 (UTC)

I think I knew that already to be honest. Isn't it pretty disgraceful that with an income in the tens of millions, the WMF can't find any resources to allocate to support for mathematics? Deltahedron (talk) 19:11, 18 April 2014 (UTC)

That's my point. It's really not a very pleasant work to break down everything into atomic changes. With the new version of the Math extension that Gabriel Wicke and me developed in September last year MathJax is executed on the server side, which solves the performance problems. The problem with this development was that it changed from the old version to the new one in one step. I turned out that nobody from the foundation would ever find time to do a code review for such a large change. Therefore I had to break down this change into a number of small commits. This is really a lot of useless work and causes some unfortunate side effects. I'd really appreciate if the Foundation could allocate some paid developers to review the changes in the Math extension at once. But it seems that there is no money for the math extension so everything has to be developed and reviewed for free.--Physikerwelt (talk) 11:43, 19 April 2014 (UTC)

Is there a test wiki we can see this in action? I tried doing all the vagrant stuff but got lost git problems. It would be nice to see what then end results of your hard work are going to be.

I've started a thread at User talk:Jimbo Wales/Archive 161#The problem with developing maths rendering. Maybe that can help bring some foundation attention.--Salix alba (talk): 14:02, 19 April 2014 (UTC)

What are the long-term plans anyway? I use "render as PNG" since it usually works and is at least ten times faster than MathJax. Please don't tell me it's going to be MathJax only. YohanN7 (talk) 19:22, 18 April 2014 (UTC)

No. See the demo (based on the Math2.0 code from Oct. 2013) http://math2.beta.wmflabs.org/wiki/Dedekind_sum. With Firefox you see MathML and with Chrome the SVG output of clientside MathJaX rendering.

The checkbox option for the orthogonal client-side mathjax rendering option is availible for registed users in addition. --Physikerwelt (talk) 11:57, 19 April 2014 (UTC)

On this page I'm seeing nothing - lots of empty formulae - but for one error (the second of the two formulae here):

Failed to parse(MathML (with SVG fallback): Invalid response ('There was a problem during the HTTP request: 500 Internal Server Error') from server 'http://mathoid.eqiad.wmflabs:10042':): s(b,c)={\frac {1}{4c}}\sum _{{n=1}}^{{c-1}}\cot \left({\frac {\pi n}{c}}\right)\cot \left({\frac {\pi nb}{c}}\right).

This is with Safari 5.1.10 on Mac OS 10.6.8. On first reading 'That's my point...' my thought was something like this, i.e. hosting it on a separate server. That's how Lua was tested on test2. Then promote the heck out of it on here, at the Village Pump, any other math rendering related pages, and any discussion that math rendering's raised. That should given time let it be thoroughly tested and demonstrated to convince people to accept it in one go. --JohnBlackburne^words_deeds 18:27, 19 April 2014 (UTC)

And I'm seeing a mass of LaTeX source code and the same red error message (Fedora/3.6.24-1.fc14 Firefox/3.6.24). Deltahedron (talk) 18:41, 19 April 2014 (UTC)

I'm getting problems with Help:Formula not rendering with MathJax switched on. I'm getting

  GET http://en.wikipedia.org/extensions/MathMenu.js 404 (Not Found)  GET http://en.wikipedia.org/extensions/MathZoom.js 404 (Not Found)

which is odd as they are the wrong urls. I'm not sure if its some problem with my set up or a cache bug. I've narrowed down the problem a bit my sandbox does not render correctly. It would be good if someone else to verify if its a bug. --Salix alba (talk): 06:52, 21 April 2014 (UTC)

Seemed to be a problem with using MathJax as a section title. Fixed now.--Salix alba (talk): 07:51, 21 April 2014 (UTC)

See https://en.wikipedia.org/wiki/User_talk:Salix_alba#Math_demo --Physikerwelt (talk) 11:21, 21 April 2014 (UTC)

Perhaps meta.wikimedia.org/wiki/Grants_talk:APG/Proposals/2013-2014_round2/Wikimedia_Foundation/Proposal_form might be a good place to ask WMF about their future plans. Deltahedron (talk) 18:43, 21 April 2014 (UTC)

Gabriel and me wrote a paper about the future of the Math extension. The preview is availible at arxiv. For the reference I'd like to add a link to the gerrit code review web interface and the development branch of the Math extension that already uses MathML and SVG. Physikerwelt (talk) 10:14, 25 April 2014 (UTC)

AfC submission - 25/04

Wikipedia talk:Articles for creation/Chain Decomposition. FoCuSandLeArN (talk) 15:21, 25 April 2014 (UTC)

Wikipedia talk:Articles for creation/James Maynard. FoCuSandLeArN (talk) 20:12, 25 April 2014 (UTC)

Arthur Engel (mathematician)

I created this article recently, but am really struggling with sources. I'm hoping someone here may be able to help? Thanks, Boleyn (talk) 08:01, 26 April 2014 (UTC)

It has now been referred to Wikipedia:Articles for deletion/Arthur Engel (mathematician), so any help would be appreciated. Best wishes, Boleyn (talk) 13:54, 26 April 2014 (UTC)

Merger help request

Transclusion from Requested Merger Noticeboard involving B-Class article:

Merge Calculus and Infinitesimal calculus. Discussion >>>HERE<<<. Unsigned request -68.145.242.176 Talk 18:01, March 28, 2014? (UTC)

Tagged and awaiting consensus. GenQuest ^{"Talk to Me"} 00:05, 30 March 2014 (UTC)

Overwhelming early support for merge indicates that proposer or someone familiar with the subject(s) can proceed boldly. GenQuest ^{"Talk to Me"} 03:50, 4 April 2014 (UTC)

Working Consensus is for merger to proceed by interested editor or proposer. GenQuest ^{"Talk to Me"} 05:19, 16 April 2014 (UTC)

=> Can someone here help with this? Regards, GenQuest ^{"Talk to Me"} 19:37, 26 April 2014 (UTC)

Wikipedia talk:Articles for creation/Adaptive Filtering by Optimal Projection

Dear mathematicians: I'm not sure if this is the right place to report this, or if it is more physics or engineering. In any case, should this old Afc submission be kept and improved, or is there content that should be added to Adaptive filtering? --Anne Delong (talk) 02:37, 27 April 2014 (UTC)

Royal Society journals - subscription offer for one year

I'm delighted to say that the Royal Society, the UK's National Academy for science, is offering 24 Wikipedians free access for one year to its prestigious range of scientific journals. Please note that much of the content of these journals is already freely available online, the details varying slightly between the journals - see the Royal Society Publishing webpages. For the purposes of this offer the Royal Society's journals are divided into 3 groups: Biological sciences, Physical sciences and history of science. For full details and signing-up, please see the applications page. Initial applications will close on 25 May 2014, but later applications will go on the waiting list. Wiki at Royal Society John (talk) 02:51, 29 April 2014 (UTC)

May 2014

Zorn's lemma

The article on Zorn's lemma reads like a textbook, giving an example application in great detail and sketching a proof. I would like to remove these two sections to make the article more encyclopedic, but I wanted to get feedback before going forward. Brirush (talk) 16:15, 1 May 2014 (UTC)

No examples and no proof outlines doesn't automatically make anything more encyclopedic. But it might make something decidedly worse. Zorn's lemma is important enough to warrant both a proof outline and a sample application in my opinion. But the present proof and example are admittedly horribly textbooky, so I wouldn't scream out loud if you removed them. But better is to rewrite them. YohanN7 (talk) 16:34, 1 May 2014 (UTC)

I think the problem isn't so much with the content as with the writing style, which is too informal for an encyclopedia. I don't think any content should be removed, but the article should be cleaned up stylistically. S?awomir Bia?y (talk) 14:52, 2 May 2014 (UTC)

Just since it's so irrelevant, Wikipedia's cofounder Jimmy Wales once had a chance encounter with Max Zorn. I suspect one could find some of his comments about it via Google. Michael Hardy (talk) 14:24, 2 May 2014 (UTC)

Disambiguation help needed for Completeness

Greetings! The disambiguation page Completeness has many incoming links, putting it near the top of our list of most-linked disambiguation pages. It turns out that a lot of these links refer to one of the many mathematical senses of the word, so the expertise of this project in fixing those links would be greatly appreciated. Cheers! bd2412 T 16:32, 2 May 2014 (UTC)

VisualEditor math formulae

Hi everyone,

I wanted to let you know that James F is hoping to move VisualEditor's TeX-based math formula editor out of its opt-in-separately status next week. They just fixed the last batch of bugs, so it should be relatively stable at this point. This won't change the status of VisualEditor on the English Wikipedia; however, to edit math formulas, you won't have to separately opt-in to the math editor in addition to the main VisualEditor editing environment. At most other Wikipedias, it will be available to everyone.

If you haven't tried it out yet, please go to Special:Preferences#mw-prefsection-betafeatures and opt-in. If you know of (or find) any big bugs, or if there's some reason why you believe that letting everyone use this tool is a bad idea, then please let me know by the end of Wednesday (if possible). Bugs can be reported to Wikipedia:VisualEditor/Feedback if you want. Thanks, Whatamidoing (WMF) (talk) 01:44, 26 April 2014 (UTC)

Some great big bugs.

When using MathJax editing a simple formula will severely mess up how its displayed. bug 61497http://bugzilla.wikimedia.org/show_bug.cgi?id=61497
After an editing session (i.e. clicking save) the mathjax will not be reloaded as VE does not do a full page reload. bug 51565http://bugzilla.wikimedia.org/show_bug.cgi?id=51565bug 36060http://bugzilla.wikimedia.org/show_bug.cgi?id=36060
The popup box is way to small, and can obscure the text of the equation. Could be solved by making it movable and resizable.bug 57437http://bugzilla.wikimedia.org/show_bug.cgi?id=57437

These are the show stoppers for me.

The VE team should also coordinate with @Gwicke: on this issue. There are plans to completely change the maths backend. Moving away from the outdated png maths renderer to a mathml/mathjax based one with cached images. [14]--Salix alba (talk): 08:16, 26 April 2014 (UTC)

How long has it been since you looked at the display bug? That equation displays correctly for me in Firefox and in Safari. If it's not working for you, then please tell me your browser/skin/OS information again.
The page updated the formula upon save for me (and also while the math formula editor was open, after a delay of about a second or so). Whatamidoing (WMF) (talk) 00:09, 27 April 2014 (UTC)

Display bug happened just now. I even turned off all my extensions. I'm using the latest chrome on mac 10.9. I get the same with firefox. The problem with refreshing after save seems to be ok now.

BTW it does not give me a Edit Beta tab in firefox. I need to manually type the url to get to use VE in firefox. --Salix alba (talk): 06:48, 27 April 2014 (UTC)

Salix alba,

How long has this been going on? Do other things (like Twinkle) load for you? Is your screen somewhat narrow? Is the History tab displaying? Does it only happen when Wikipedia seems to be slow? If you've opted in, it should be there. Whatamidoing (WMF) (talk) 20:41, 27 April 2014 (UTC)

Also with a large formula the selection region you need to hover over to get the ? to appear is very small. Ideally it should be the full size of the equation. --Salix alba (talk): 11:16, 26 April 2014 (UTC)

I agree. As a workaround, you can use cursor keys to select it. Just press the arrow key until you're on top of the formula. Whatamidoing (WMF) (talk) 00:09, 27 April 2014 (UTC)

Wow, I hope that removing the TeX renderer never comes to pass. I have tried converting over to MathJax, but the MathJax typography is buggy to the point that I cannot bear to stick with it. The TeX renderer just works. --Mark viking (talk) 16:07, 26 April 2014 (UTC)

The formula editor isn't invoked for numbered equations (using template NumBlk). Also, the whole package is so slow that it tends to be confusing. It takes forever to load a big article for editing (even when you want to edit a tiny section), once you are done, it takes forever again to see the actual effects of the edits. Imo, the VE stuff should stay as beta for the foreseeable future. YohanN7 (talk) 20:23, 26 April 2014 (UTC)

The proposed change here only affects people who are already using VisualEditor. At the English Wikipedia, you would still have to opt-in to VisualEditor. Whatamidoing (WMF) (talk) 00:09, 27 April 2014 (UTC)

@Salix alba: Thanks for your thoughts - some notes and queries:

bug 51565http://bugzilla.wikimedia.org/show_bug.cgi?id=51565 was fixed six months ago; are you still having issues with this?
bug 36060http://bugzilla.wikimedia.org/show_bug.cgi?id=36060 is a bug in the MathJax system, and does not affect VisualEditor AFAICS.
bug 57437http://bugzilla.wikimedia.org/show_bug.cgi?id=57437 is a blocked on a long-term request for improving the flexibility in the OOjs UI system on which VisualEditor is built, and won't be fixed soon.
bug 61497http://bugzilla.wikimedia.org/show_bug.cgi?id=61497 is a bug that only affects people editing multi-line formulæ who have the MathJax preference (which is marked "experimental" for a reason) switched on.
The region being the wrong size is something we need to fix, but shouldn't be too hard.

Based on these, I think it will be OK to go ahead, and we will try to get these fixed quickly.

Jdforrester (WMF) (talk) 20:04, 29 April 2014 (UTC)

@Jdforrester (WMF): 51565 works for me now, 36060 was just for reference.

57437 has two part, movable and resizable. If you look at the above screen shot you see for a large formula the dialog window obscures what you are trying edit. If you can see the result of what your trying edit it makes for a bad ui experience.

bug 61497http://bugzilla.wikimedia.org/show_bug.cgi?id=61497 is a consequence of bug 52499http://bugzilla.wikimedia.org/show_bug.cgi?id=52499 which breaks any content using css-positioning. Most guides to CSS say !important is something to be avoided. For me if its a choice between having to use MathJax and the wikitext editor or VE and png/texvc thens its MathJax every time. Another minor annoyance is that with a large formula the region you need to click the mouse on is quite small, I'm having to spend time trying to find the region to click on. bug 64625http://bugzilla.wikimedia.org/show_bug.cgi?id=64625 --Salix alba (talk): 21:44, 29 April 2014 (UTC)

Also bugzilla:36060 should be fixed for VE now. MathJax hooks on wikipage.content now and should redraw. The bug isn't fully fixed (because it's actually about LivePreview), where it still has a small dependency on another bug, but that should not affect VE I think. --TheDJ (talk o contribs) 22:02, 29 April 2014 (UTC)

@Salix alba and TheDJ: Yeah, the bit in 57437 about the window opening in the wrong place is actually a totally different bug ("The [selection] region being the wrong size") which we'll fix anyway. Jdforrester (WMF) (talk) 23:49, 29 April 2014 (UTC)

I think that if the problem with the too-small selection region is fixed, then the tool will automatically quit covering up the formula. Whatamidoing (WMF) (talk) 15:25, 30 April 2014 (UTC)

Is the poor performance of MathJax due to MtheJax iteslf (being a Java Script), or is it due to poor utilization of it? I am curious to know, since with modern day computers, and with today's internet technology, it's practically impossible to get something as slow as this, at least it is so if you put your minds to it. YohanN7 (talk) 22:18, 29 April 2014 (UTC)

There are multiple reasons.

It's not the most optimized script that has ever been written. I'm not calling it bad code or anything, but if you put a JS wizard king on it you probably can still optimize it considerably.
The default mode is HTML-CSS, which is the best supported cross browser. This is also it's slowest mode, but the most consistent, with the best final results (because it has the least dependencies on browser features). Note that you can choose different render modes (SVG and MathML) by right clicking a formula. MathML is suboptimal for some browsers, SVG might give very good results and is faster, if you have the proper fonts.
Keeping track of what works how well in which browser version is a problem in itself. MathJax for instance by default was using MathML in FF for quite a while and then disabled it again. It was a lot faster, but there were simply too many imperfections. If browser support was further along, or more consistent, MathJax could work a LOT faster.
Wikipedia pages are BIG. Really, our website has a lot of content, and a lot of features. It's optimized to death, but compared to more focused websites, it probably is still big. That makes something like mathjax inherently slow right now. Part of why Mathjax is so slow simply has to do with the fact that we are not able to treat every single page in the encyclopedia as a math page.

A lot of improvements can be made, for sure. The problem is that it is all dependent on a very small group of developers. I would encourage everyone to support and encourage the developers of MathJax.org. They really are doing a great job, considering the browser and operating system madness that they have to work with. Of course it is idiotic that we need MathJax to begin with, but building and proofing that MathJax CAN do it, is the best way to get this fixed in OS'es and browsers I think. Also the steps of physikerwelt and GabrielWicke referred to by Salix alba, actually prepare our 'content' for exactly these better times, while at the same time allowing us to continue to support png rendering, but adding svg rendering, semantic math (helpful for search engines) and pdf/book rendering (all problem areas right now). All enhanced with MathJax for those that desire it, or for who it makes sense. It's a long path, but at least we are seeing progress now, for the first time since 2004'ish. --TheDJ (talk o contribs) 14:37, 30 April 2014 (UTC)

Thank you @TheDJ: for the informative answer. I didn't see this until now, which explains, to some extent, my sort of (too) negative comments below. I'm all for getting MathJax rendering into good shape because of its visual appeal and the future potential of having inline math using it as well. (This is a big big no-no with the PNG rendering.) Keep up the good work! YohanN7 (talk) 09:48, 2 May 2014 (UTC)

My advice would be to try to keep down the conversation between client and server to a minimum. As I said, it is impossible to get something as slow as MathJax when running on a single machine (well, unless you use dot net of course, then everything is possible). The explanation must be that the client and server is talking to much. YohanN7 (talk)¨

the MathJax preference (which is marked "experimental" for a reason) -- really: and what reason would that be? More precisely, what are the plans for development of MathJax and its integration into VE? Just saying it's "experimental" tells us rather little. Deltahedron (talk) 06:10, 30 April 2014 (UTC)

@Deltahedron: Bugs, missing features, slowness, ... - take your pick. There's been a huge amount of work by Mauritz to make MathJax a beautiful, simple, fast experience for all our users, and Jaibao, the GSoC student who worked on the initial VisualEditor plugin for formula editing last year was looking at the next step of using MathJax not only to render but also to write formulæ, as an alternative to LaTeX. I don't know if that has gone any further. Jdforrester (WMF) (talk) 17:42, 30 April 2014 (UTC)

That really is not an adequate answer to a perfectly serious question. Firstly, I don't know whether MathJax, as currently instantiated on English Wikipedia, is buggy, slow or whatever, and if I did I probably would not have asked the question. Is it any or all of those things -- I don't know and so can hardly take my pick. Secondly, "experimental" does not mean, or imply, any or all of those things. Software can be buggy or slow without being experimental, and can be experimental without being buggy, slow or deficient in features. "Experimental" implies that it is being tried out for a reason, usually with a definite set of criteria against which it will be judged, by a definite group of people and on a definite timescale. What are those in this case, please? Thirdly, I find it surprising to say the least that the Product Manager, VisualEditor team is unwilling or unable to say what the plans for mathematics rendering are or what progress has been made against those plans. Please involve the community in your thinking and I am sure we will be able to help. Give us this unserious sort of brush-off and we can not. Deltahedron (talk) 21:22, 1 May 2014 (UTC)

@Deltahedron: You seem to be confused; I have no product management relationship with the formula editor, I'm just speculating as to why it's still listed as "experimental" after several years. If you want answers, you should ask the volunteers who maintain that extension what their plans are. I don't know what they are. Jdforrester (WMF) (talk) 21:52, 2 May 2014 (UTC)

James F appears to be offline at the moment, so let me attempt a clarification on his behalf: When he says, "I have no product management relationship with the formula editor", I believe that he means "I have no product management relationship with MathJax's formula editor", not VisualEditor's formula editor. Whatamidoing (WMF) (talk) 23:01, 2 May 2014 (UTC)

Thank you for clarifying that. User:Jdforrester (WMF)'s answer seems illogical. I posted an open question on this discussion group and he answered it. He admits that his answer was merely speculation, but astonishingly tells me that it's my fault I did not get a proper answer because I should not have asked him. He then proceeds to ignore the part of the question he really ought to know the answer to ("what are the plans for [MathJax] integration into VE"). However the point of my question is:

What plans does WMF have for mathematics rendering on en.wikipedia?
Specifically, what are the plans for development of MathJax within WMF products and its integration into VE?

Please could we have a clear answer to those questions? As I have said before, the mathematics community here is capable of helping if only WMF would engage with us in a sensible way. Deltahedron (talk) 06:34, 3 May 2014 (UTC)

@Deltahedron: "volunteer driven".... As far as I'm aware, WMF has 0 and no plans on Math. Just as they have no plans on SVG, on 3D models, on WebP, on Timelines and graphs, on document proofreading, dictionary functionality, book writing, news writing, etc etc etc. --TheDJ (talk o contribs) 20:12, 3 May 2014 (UTC)

That may well be so. But I would like to hear a clear statement from someone at WMF in a position to make a pronouncement on this subject. It is proving surprisingly difficult to get such a thing. Deltahedron (talk) 20:20, 3 May 2014 (UTC)

@Deltahedron and TheDJ: I'm sorry for the confusion; I assumed denizens of WikiProject Mathematics, if no-where else, would be aware of the nature of engineering support in place for the mathematical functions in MediaWiki and had made a decision that they weren't going to help out those few volunteer developers working on it. Certainly it's a frequent topic of discussion when I talk to hard-science-related topic editors how the tools at the editing communities' disposal could be better supported. (TheDJ is entirely correct, as always.) Jdforrester (WMF) (talk) 05:12, 4 May 2014 (UTC)

Thank you for that reply. I do not know why you would make that assumption, and as far as I personally am concerned it is quite incorrect. I have no idea what the nature of engineering support is for mathematics functions, because I have never seen any such description, I do not know where to go to find it, and my repeated questions on the subject here and elsewhere have not been answered. It is therefore impossible for me to have made any kind of decision of the sort you suggest.

However we are at least one step further on. As I understand it, User:Jdforrester (WMF), using his official WMF account has stated that the following is an entirely correct description of the WMF plans for mathematics rendering and specifically the plans for development of MathJax within WMF products and its integration into VE:

WMF has 0 and no plans on Math.

Am I the only person who thinks that the WMF's position here is lamentable? Anyway, I have (again) asked Jimbo Wales to pursue the matter with WMF [15]. Deltahedron (talk) 08:37, 4 May 2014 (UTC)

Depends, like I stated, there are a quite a few more niche areas that get 0 support. I would say undesirable, but then again, WMF can only keep in the air as many balls as it is able to juggle at that time and thus it needs to prioritize. Also remember that almost EVERYTHING we EVER did up to 2010 was volunteer driven. So why do we think everything needs to be done by WMF these days ? --TheDJ (talk o contribs) 09:49, 4 May 2014 (UTC)

Because someone has to plan and coordinate what's going on, otherwise that volunteer effort is likely to be largely wasted; because we already have complaints that the way the substantial amount of paid development work is organised is making it hard for volunteers to get their work done; because WMF is already spending a lot of time and money on radical changes such as Visual Editor and Flow which means that mathematics markup, rendering and editing is going to have to change, like it or not, and a lot of work will have to be done by someone just to sustain existing capabilities; and because WMF has raised an income of some $30M and over 100 staff precisely in order to do this sort of work. Deltahedron (talk) 10:23, 4 May 2014 (UTC)

Everyone is appreciating that good work goes into this. But this is not the problem. One problem is that performance issues must be dealt with. If not, the whole discussion will be like that when Java was entirely new. The Java enthusiasts argued that Java was bleedingly fast, when, in practice, it is was acceptably fast only if you had a super-computer able to haul the thing. I'm afraid that MathJax might turn out to be fast only if you have a 10 Giga-bit internet connection and/or a less-than-two-years-old machine. This would be ridiculous, considering that we are really only displaying text on a screen, something acceptably fast since the Windows 3.1 days. I'm still curious about why MathJax is so much slower than sever-generated PNG. Does it fetch fonts every time it runs if I don't have them locally? YohanN7 (talk) 16:53, 1 May 2014 (UTC)

Personally I don't find the performance issues with MathJax very problematic, even a heavy page like Help:Formula can be completely rendered in about 20s. I find the time of rendering roughly comparable with the time it takes to download all the png images. I do have all the MathJax fonts and the STIX fonts installed locally which make things quicker and look better. In fact the download time is always quicker with mathjax (if you have local fonts) than png. --Salix alba (talk): 23:08, 1 May 2014 (UTC)

Hmmm. Just like the old days Java arguments. It is fast (even though it is very very slow). I see the 20s or so for Help:Formula too. I have MathJax fonts installed, but not the STIX. It should take less time than a human would notice as a delay to render even that page if it was properly implemented. Granted, this is more annoying than very problematic. I tend to switch back and forth between MathJax and PNG. MathJax is much prettier, but sooner or later, I switch back because of the poor performance. YohanN7 (talk) 08:04, 2 May 2014 (UTC)

Gini coefficient discussion

Project members are invited to look at Talk:Gini coefficient#Gini in Template:infobox country and to provide input. - S. Rich (talk) 04:24, 6 May 2014 (UTC)

And , if they can cope with it, Kakwani index. All the best: Rich Farmbrough, 18:22, 6 May 2014 (UTC).

Elementary symmetric polynomial

Hi!

I am usually a proponent of having (even detailed) proof outlines in the articles, but here, there is a proof outline, an alternative proof and a self-contained algorithmic proof of the same theorem. All of them are fat, and none of them have references. I don't want to just remove (some of) them without some form of consensus. There are probably few watchers on that page, therefore I raise the issue here. YohanN7 (talk) 21:01, 18 April 2014 (UTC)

If they are unreferenced then I would remove them as such per WP:BRD. Deltahedron (talk) 21:18, 18 April 2014 (UTC)

I've removed the third proof; it was observed redundant already when it was first added, so I don't know why it survived this long. I personally am inclined to also remove the first proof and leave only the second one (which is the version that one can find e.g. in Stanley's EC2, as Thm. 7.4.4), but I will leave that for someone else to decide. I would not remove all three proofs.--JBL (talk) 15:49, 6 May 2014 (UTC)

Yes, retaining one of them is probably the right thing to do, with references, if possible, so I support your suggestion. YohanN7 (talk) 16:05, 6 May 2014 (UTC)

Input requested about possible hoax

Hi all, if I could get some input at this thread, it'd be much appreciated. Regards, Daniel (talk) 13:42, 28 April 2014 (UTC)

It was a made up name with fake references now deleted Chihiro number. It is a real sequence with OEIS reference [16]. The hoax has spread to that page so if anyone has an OEIS login it would be good to fix that.--Salix alba (talk): 14:42, 28 April 2014 (UTC)

I've deleted this but the hoaxer achieved his goal of making it a DYK. It very much looks as though it was someone who knows about mathematics - changed the section heading as it would be nice to identify the hoaxer although I don't expect we will. Dougweller (talk) 14:57, 28 April 2014 (UTC)

OEIS is already on the case although it seems that their removal of the hoax link has not yet been finalized. --David Eppstein (talk) 18:04, 28 April 2014 (UTC)

I love a good hoax--and this was a good one. But I never ever said this! YohanN7 (talk) 15:18, 29 April 2014 (UTC)

Sorry I didn't do anything about this: I noticed it before it went on the front page via my occasional visits to Tomorrow's Main Page, thought it looked dubious but with my poor track record of nominating stuff for deletion which gets kept I left it alone. Should have at least posted here for more expert opinions.

I've done (created + reviewed) DYKs in the past and can easily see how this would get through. The reviewer is meant to check refs but they have to AGF for offline refs which for many articles are the only sort. There's no requirement or even recommendation the reviewer is an expert or should seek one, as long as they can understand the article enough. You can see how this was crafted to be obscure enough that it wouldn't be obviously dubious but also not so technical that it needed an expert who would be more likely to question it.--JohnBlackburne^words_deeds 18:05, 29 April 2014 (UTC)

"no requirement or even recommendation the reviewer is an expert"? Perhaps there should be? Deltahedron (talk) 18:22, 29 April 2014 (UTC)

Another reason for mathematicians to watch the front page and DYK queues. This slipped through:

... that even though the range of the Beautiful Nuthatch (pictured) is very large, approaching 376,000 km² (234,000 mi²), the species is nevertheless rare, being highly localized in its distribution?

D'oh. It doesn't especially require a mathematician, just someone with some arithmetic ability, but it got as far as the front page. I spotted it too late, just before it was replaced.--JohnBlackburne^words_deeds 18:34, 6 May 2014 (UTC)

Current activity

No new articles in Wikipedia:WikiProject Mathematics/Current activity for the last couple of days. Do we really have no new articles or does one of the bots need kicking again? --David Eppstein (talk) 02:22, 4 May 2014 (UTC)

Option B I think. Just one day without new articles is exceptionally unlikely. Three and something's up.--JohnBlackburne^words_deeds 02:30, 4 May 2014 (UTC)

I wrote to Jitse Niesen about this before David Eppstein's comment appeared above. Today I wrote to Oleg Alexandrov about it. Oleg runs the other bot involved. Jitse's bot edits the current activities page daily; Oleg's bot edits the list of mathematics articles daily. Jitse's bot gets its information on new articles from the edits done by Oleg's bot. Jitse's bot is still doing daily edits; Oleg's bot hasn't done its daily edits since the end of April. Michael Hardy (talk) 12:21, 5 May 2014 (UTC)

Oleg has now replied and he says he's fixed the bot. I expect all new articles created in May will appear soon. Michael Hardy (talk) 16:26, 7 May 2014 (UTC)

Probable trolling over at Naive set theory

Don't think this one is doing "good faith" edits. Seems to be just a bit too smart not to have gotten the message by now - and just about smart enough to intentionally misinterpret your attempts to reason with it in such a way as to make you the idiot.

If I revert more myself, I'll surely be banned for a century. If I post more, I'll just be feeding it. YohanN7 (talk) 11:37, 5 May 2014 (UTC)

I don't think he's a troll; I think he's a crank. Cranks inhabit a world of their own; not only can we not contact that world, more importantly, they can't contact ours. To them our logic appears to be a sequence of non-sequiturs, so there's no hope arguing with such a person. It's best to leave them alone, if possible. Since our set-theoretic friend seems intent on adding his ideas to the naive set theory page, some others of us may need to assist you in reverting him. Ozob (talk) 14:23, 5 May 2014 (UTC)

He has shown tendencies of being both a little bit of a troll and a little bit of a crank. He does understand new things (perhaps only after being allowed to figure them out for himself, making it his conclusions). The whole thing is now over at the reference desk, and is harmless. YohanN7 (talk) 14:47, 5 May 2014 (UTC)

It may be helpful to ask for page protection if an IP user persists in edit warring on an article. Deltahedron (talk) 15:31, 5 May 2014 (UTC)

Might be an idea. His last conclusion over at the reference desk was that now he had answered all the questions about why his set theory is guaranteed to be without paradoxes, and the only remaining thing was to revert the reverts of his edits in the article. If he begins, I'll ask for page protection.

Sort of funny, when you are in the age when you begin to actually learn something, but before the age when you learn more and find out that you actually know close to nothing, then you may come close to think that you know it all, almost at least. I recognize these tendencies in people, including myself in the undergraduate days. But this guy is extreme. YohanN7 (talk) 17:26, 5 May 2014 (UTC)

In light of this discussion I've semiprotected Naive set theory. If the protection turns out not to be necessary it can be lifted. EdJohnston (talk) 18:04, 5 May 2014 (UTC)

I have lifted the semi-protection since the ip-user now has a real user account. He doesn't seem prone at all to be doing pure vandalism (while not being logged in). YohanN7 (talk) 16:11, 8 May 2014 (UTC)

Where can I find the proper procedure to propose a change of the name of an article? Is it to be found in Wikipedia:WikiProposed WikiMoves or, if not, where? I am aware of the "move" tab in the article itself. The article's title is questionable, and I could see it as instead being "Informal set theory" for a few good and a few bad reasons. I'm neutral in this respect myself, and I would like to see your opinions on whether a move is a good idea. YohanN7 (talk) 17:51, 6 May 2014 (UTC)

Try Wikipedia:Requested moves. Deltahedron (talk) 18:03, 6 May 2014 (UTC)

"Naive set theory" is a term in common use within mathematics for this sort of set theory, so I think a move would be inappropriate in this case. S?awomir Bia?y (talk) 18:17, 6 May 2014 (UTC)

Well, except I'm not sure it's a neutral term. See the talk page of that article. I think it's at least worth entertaining the idea that a neutral article would be easier to write under a different title (for example, informal set theory). --Trovatore (talk) 22:14, 6 May 2014 (UTC)

I've added the {{Requested move}} template to the top of the existing thread at Talk:Naive set theory#Proposed move. This converts it into an official move discussion that will be listed in WP:RM and will be closed after seven days. EdJohnston (talk) 01:06, 8 May 2014 (UTC)

Leaflet For Mathematics At Wikimania 2014

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Adikhajuria (talk) 10:32, 9 May 2014 (UTC)

Predicate calculus

Should it redirect to Predicate logic or First-order logic? All the best: Rich Farmbrough, 18:22, 6 May 2014 (UTC).

Predicate logic, at least according to the article Predicate logic. Predicate logic includes first-order logic, but also second-order logic, etc, as well as predicate calculus (according to some), on which we don't have a separate article.

Of course, I'm just guessing, but it would make more sense to direct it to a parent than directing it to its cousin first-order logic. YohanN7 (talk) 15:40, 12 May 2014 (UTC)

Also, Predicate logic is short enough to be a disambiguation page (of sorts). The user will soon enough find a link to what he's looking for. YohanN7 (talk) 15:43, 12 May 2014 (UTC)

Cameron-Martin_theorem#Motivation

This is the most extreme case I've seen of overly abstract writing in a Wikipedia article. Everyone including most non-mathematicians has some idea how the the standard n-dimensional normal distribution behaves, but the first sentence in that section is phrased so as to be comprehensible only to analysts. I may try to rewrite it if no one beats me to it. Michael Hardy (talk) 17:47, 12 May 2014 (UTC)

Interestingly, it is so formulated from the very first version, of 2006. Boris Tsirelson (talk) 18:00, 12 May 2014 (UTC)

I think you're being a little unfair in your characterization of it. I think it could benefit from an explanation of what is meant in less abstract terms, but I don't think the statement via the Radon-Nikodym derivative is overly abstract for a topic of this sort. S?awomir Bia?y (talk) 18:32, 12 May 2014 (UTC)

OK, maybe I was a bit extreme, but certainly the Radon-Nikodym derivative can be written in a style that's not so notation-intensive. Michael Hardy (talk) 23:07, 12 May 2014 (UTC)

AfC submission - 13/05

Wikipedia talk:Articles for creation/A Proof of the Reconstruction of Disconnected Graphs. Is there anything salvageable there? Thanks, FoCuSandLeArN (talk) 14:44, 13 May 2014 (UTC)

No, pure OR, no encyclopedic content. --JBL (talk) 15:24, 13 May 2014 (UTC)

I agree. --David Eppstein (talk) 15:42, 13 May 2014 (UTC)

Wikidata

Just going to announce that there is now a related project on Wikidata: d:Wikidata:WikiProject Mathematics. Any help or a visit is much appreciated (signing your name and adding the page to your watchlist is even better). You may also ask questions about Wikidata's activities on the talk page. Especially input about new properties, desired data, or problems with inter-language links can be organized on that page. - And to give you an impression of what we are doing you can look at some of the data we can provide for the dodecahedron: http://tools.wmflabs.org/reasonator/?&q=178296 - Currently we can only learn that its facet is a pentagon, but hopefully much more will be available soon. --Tobias1984 (talk) 21:28, 15 May 2014 (UTC)

Firoozbakht's conjecture

Further opinions would be welcome at the article talk page. Deltahedron (talk) 09:21, 18 May 2014 (UTC)

COTM

{{Current-Math-COTM}} has been nominated for deletion -- 65.94.171.126 (talk) 07:03, 19 May 2014 (UTC)

AfC submission - 19/05

Draft:General Purpose Analog Computer
Draft:FlowSort. FoCuSandLeArN (talk) 22:38, 19 May 2014 (UTC)
- The GPAC is clearly a notable topic (papers by people other than the original creator of this model hundreds of citations in Google scholar) and the article on it looks in acceptable shape. FlowSort does not appear to be notable (Google scholar finds papers mainly by the originators of the topic, not counting unrelated papers using the same name for something else, and these papers have from zero to two citations each) and the writing in the draft article is so unreadable that I think some of it must have been generated by machine translation. My suggestion would be to accept GPAC and reject FlowSort. --David Eppstein (talk) 23:00, 19 May 2014 (UTC)
  - I agree that GPAC is notable and that the article looks acceptable. I also agree that FlowSort should be rejected; and while it's a minor point, I don't think the article is the result of machine translation but is instead written in the obfuscated style of someone who has accomplished nothing but wants to appear productive. Ozob (talk) 03:37, 20 May 2014 (UTC)
    - The wonderful English phrase "mumbo jumbo" is an apt description of the latter article, in my opinion. S?awomir Bia?y (talk) 22:35, 20 May 2014 (UTC)
      - The creator of the second article evidently became impatient: FlowSort. --JBL (talk) 23:05, 20 May 2014 (UTC)
        I have prodded the FlowSort article. Ozob (talk) 02:14, 21 May 2014 (UTC)

Spherical law of tangents

At Law of tangents we find this:

The law of tangents for spherical triangles was described in the 13th century by Persian mathematician Nasir al-Din al-Tusi (1201-74)

But it doesn't go on to state that law. Does anyone know it? Michael Hardy (talk) 19:28, 18 May 2014 (UTC)

Seems to be this. Deltahedron (talk) 19:33, 18 May 2014 (UTC)

The attribution may also be unclear: [17]. --Quondum 19:44, 18 May 2014 (UTC)

I've added a short new section to the article, citing the CRC book cited by Deltahedron: Law_of_tangents#Spherical_version. Michael Hardy (talk) 19:39, 22 May 2014 (UTC)

Execrable "help" with TeX offerred by web sites

There are web sites that purport to assist people in setting mathematical notation into TeX or MathJax code. So I am told by people who use them, but I have no URLs to cite. They write things like this:

{ {f} \left({ {{{x}}} + {{{ y }}} }\right)^{{ {2} }} } + { \frac { expression } { { { expression } } } } - { \sum_i { {a}_{i} } }

It would suffice to write this:

f(x+y)^2 + \frac{expression}{expression} - \sum_i a_i

Obviously this can make editing difficult and one failure to count superfluous left and right curly braces while editing can destroy a line, and the error can be hard to find.

I've seen this a number of times in the past few months, and I just did this edit. My purpose in doing that edit was only to break a line into two lines using "align", but I cleaned up some of this sort of crap while doing it.

Is there some way to avoid having this pestilence infect all Wikipedia articles? Michael Hardy (talk) 20:18, 22 May 2014 (UTC)

For what it's worth, in many cases probably the actual source of things like this is machine-generated LaTeX code. --JBL (talk) 20:25, 22 May 2014 (UTC)

Ask the people who are in charge of the programs that generate that to fix them. Getting rid of superfluous brackets from expressions has been a reasonably popular task for undergraduates in computing since year dot. Dmcq (talk) 09:24, 23 May 2014 (UTC)

Half-exponential

The new article titled Half-exponential function has just two articles linking to it: a "see also" link from Exponential function and an appearance in the list of exponential topics. The article is about compositional square roots ? of exponential functions, i.e.

f(f(x))=e^{x}.\,

The article mentions growth rates, so maybe some growth-rate- and Landau notation-related articles should link to it.

So:

Which other things should link to it?
What else should be done with it?

And should we have an article titled compositional square root? Michael Hardy (talk) 19:02, 22 May 2014 (UTC)

There is Functional square root, partially in answer to all three questions. S?awomir Bia?y (talk) 19:32, 22 May 2014 (UTC)

OK, now I've redirected compositional square root to functional square root. Michael Hardy (talk) 19:40, 22 May 2014 (UTC)

How do we know that such a function even exists? If we do not, then perhaps this article should be deleted. Or changed to say that such a function cannot exist. JRSpriggs (talk) 05:56, 23 May 2014 (UTC)

The article functional square root refers to a paper by Kneser in which the functional square root of the exponential function is constructed. That source should obviously be consulted before we entertain the idea of deletion. S?awomir Bia?y (talk) 10:33, 23 May 2014 (UTC)

It's been known for some time that the functional square root of any increasing function f satisfying x < f(x) or x > f(x) exists, and it can be taken to be C^k or C^? if the original function is. Supposedly, there is an real analytic solution, but I haven't verified that. -- Arthur Rubin (talk) 19:51, 23 May 2014 (UTC)

These comments about C^k functions should be in the functional square root article. -- Arthur Rubin (talk) 20:06, 23 May 2014 (UTC)

Leaflet For Wikiproject Mathematics At Wikimania 2014

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Adikhajuria (talk) 13:46, 25 May 2014 (UTC)

Is anyone interested in taking this up? We would need to provide the following:

Does this project have a logo? Is File:Glass tesseract still.png usable? What about the social media? Deltahedron (talk) 19:41, 26 May 2014 (UTC)

I'm not wild about the glass tesseract image. My preference would be for something having more of a fractal flair, like File:3-adic integers with dual colorings.svg. S?awomir Bia?y (talk) 22:37, 26 May 2014 (UTC)

More general definition of line and surface integrals?

The articles line integral and surface integral base their definitions on a (smooth) parametrization of the curve and surface respectively. But my textbook defines the following instead:

Let f be a scalar function of three variables. The surface integral $\iint _{S}f\ dS$ over a surface S is defined by $\lim _{\lVert P\rVert \to 0}\sum f\Delta S$ .
Let g be a scalar function of two or three variables. The line integral $\int _{C}g\ ds$ along a curve C with respect to arc length is defined by $\lim _{\lVert P\rVert \to 0}\sum g\Delta s$ where s is the arc length of C.
Let h be a scalar function of two or three variables. The line integral $\int _{C}h\ dx$ along a curve C with respect to x is defined by $\lim _{\lVert P\rVert \to 0}\sum h\Delta x$ . Likewise with the other spatial variables.

In all cases, the definition includes "provided the limit exists", and ||P|| denotes the norm of the partition of a Riemann sum. In the case of the surface integral, the partitioning is done rectangularly and the norm ||P|| is the length of the longest diagonal of a rectangle among all the partitions $\Delta S$ . For the line integrals, the norm of the partition is defined analogously to the one-dimensional Riemann integral. In both cases, the sum is of all partitions over C or S. For vector fields, the definition is component-wise (e.g. the definition of work can be split (in three-dimensional space for a steady force field) into three integrals of the third kind above). Unlike the line integral's labeling of case 2 a line integral of a scalar field and case 3 a (component of) a line integral of a vector field, all three definitions can be applied to both vector and scalar fields.

I think these are better than the current definitions because they are more general with no conditions set on the integration domain - only that the limit has to exist. The book also gives the definitions in the articles as "Evaluation Theorem"s, but attaches the additional conditions such as C having to be piecewise smooth. The only concern I have is whether the expressions I typed above are well-defined. To me, it would seem they are well-defined because of the given definition of ||P||.--Jasper Deng (talk) 23:33, 26 May 2014 (UTC)

I wonder, which textbook do you read. I remember a well-known counterexample to "The surface integral

\iint _{S}f\ dS

over a surface S is defined by

\lim _{\lVert P\rVert \to 0}\sum f\Delta S

." Namely, the limit does not exist for a cylinder (and, even, a constant function on it). The problem is that a small size of a rectangle does not ensure that the normal vector to the rectangle is close (in direction) to the normal vector to the cylinder. Though, really, it was about triangles, not rectangles. But I am still in doubt. What is called "rectangular" in this context? Is it proved that the limit exists at least in some nontrivial (that is, non-flat) cases? Boris Tsirelson (talk) 05:41, 27 May 2014 (UTC)

The "rectangular" partitioning is really referring to parallelogram-shaped pieces of a curved surface. To elaborate on how the book makes this well-defined, each parallelogram is a subset of the tangent plane to the surface at each particular point chosen for each

f\ dS

. That a tangent plane exists is because the book does indeed assume that S is smooth (or at least "piecewise smooth", i.e. a finite union of smooth surfaces like the cylinder; in that case we sum over each smooth portion and add them, just like the case with a piecewise smooth curve with line integrals). This definition is independent of whether the surface is orientable or not. But yes, the smoothness of S goes to imply that normal vectors exist. Nevertheless, I still maintain that this definition is more general than the one given in the article. One advantage is that S doesn't have to have a regular projection onto any of the planes.--Jasper Deng (talk) 06:07, 27 May 2014 (UTC)

I am pretty sure that it is not so simple. I think Spivak presents the cylinder counterexample in his Calculus on Manifolds. It might also be that Federer discusses this in his Geometric Measure Theory (a quite advanced but very beautiful book), but I don't recall for certain.

In addition, I'm not so sure that it's necessary for the line integral and surface integral articles to have extremely general definitions. Because the article will be consulted on a regular basis by physicists and engineers, and because piecewise smooth sets are both much simpler than the general case and are the most common application, I think it's best if the article start with the piecewise smooth case and only mention generalizations later. Ozob (talk) 14:17, 27 May 2014 (UTC)

I would like to strongly endorse Ozob's last sentence: the articles on surface and line integrals should aim be readable by anyone whose background consists of a standard semester of computational multivariable calculus. --JBL (talk) 15:26, 27 May 2014 (UTC)

Unindenting since I don't know where else to put this. At least locally it is true that for a regular surface

\int f\,dS=\lim _{\|P\|\to 0}\sum f(x_{ij})\Delta S_{ij}

where the partitions are determined relative to some fixed parametrization of the surface, and $\Delta S_{ij}$ is the surface area of the ij-th part. This does not contradict the Schwarz paradox since one is not approximating the surface by flat pieces; only the scalar function f is being approximated by its value at some points in the partition. The analysis is needed to show that the areas ?S_ij are equal to the value of the Jacobian plus little oh of the mesh size, in order to obtain the formula $dS=|r_{u}\times r_{v}|du\,dv$ that our article surface area gives. S?awomir Bia?y (talk) 20:06, 27 May 2014 (UTC)

Yes, this should be correct. But what is gained this way? The surface should be smooth enough. True, the function need not be continuous, rather it needs to be Riemann integrable... but this is the same as Riemann integrability in the parameters, if we parametrize the surface... nothing new happens. Boris Tsirelson (talk) 20:33, 27 May 2014 (UTC)

Nothing in particular is gained. I do not mean to suggest that this is necessarily a good approach, but I just wish to point out that it does not lead to contradictions as has been suggested here. It might be marginally preferable to do things this way when intuition is more important than rigorous proofs. (Why else would we use the Riemann integral in the first place?) The formal mathematical approach is actually rather intricate, invoking both partitions of unity and change of variables. At the end of the formal process of defining the integral in a way that is both well-defined and diffeomorphism invariant, it is actually difficult to validate our physical or geometrical intuition. It fails to give a satisfactory answer why the resulting integral should be identified with the surface integral. (One good approach to answer the latter question that can be done in a serious course on the subject is to replace the surface integral by the integral over a tubular neighborhood, thus "fattening out" the surface, and then pass to a limit.) But there's probably no royal road. S?awomir Bia?y (talk) 21:29, 27 May 2014 (UTC)

Yes, this was kinda what I was concerned about the quality of my book's definition, which deliberately is restricted to surfaces where tangent planes exist everywhere (requiring differentiability). Essentially, I'm wondering about how the notion of a surface element

\Delta S

can be well-defined without using the unbent approximation using tangent plane segments.--Jasper Deng (talk) 01:47, 28 May 2014 (UTC)

What you are really asking for is a measure. For n-dimensional objects in n-dimensional Euclidean space, there is only one reasonable definition, Lebesgue measure (at least when doing geometry; for probability there are all kinds of useful measures). For smooth (or even C¹) m-dimensional objects in n-dimensional Euclidean space, again, there is only one reasonable definition. This is essentially because one can locally choose a differentiable parametrization of the set and pull back the measure to the domain of the parametrization; the change-of-variables formula for integrals says that the only reasonable thing that one can get (again, assuming that we are doing geometry) is Lebesgue measure on m-dimensional space times the absolute value of the Jacobian of the parametrization. Rougher sets, however, cannot be measured in this way, because when there is no C¹-parametrization there is no change-of-variables formula. One has to invent a new method for measuring these sets, and it turns out that there is more than one way to do so. Probably the best known is Hausdorff measure, but there are others. Handling such sets consistently is a subtle thing, but by now the technology is well-developed. The full story is too long to get into here, but the essential content is that you pick some sets, decide what their sizes ought to be, and use them to approximate other sets. Any textbook on measure theory will explain how to do this; in particular, the book of Federer that I mentioned above carries this out in the geometric situations you're interested in (though it sounds like it's rather more advanced than what you're reading). Textbooks on measure-theoretic probability also do this (but motivated by other considerations coming from stochastic processes). Ozob (talk) 04:27, 28 May 2014 (UTC)

Really, I agree with Slawomir and Jasper: something essential is gained. Boris Tsirelson (talk) 05:55, 28 May 2014 (UTC)

Robert Steinberg

An anonymous IP posted to his article that he had died. Can anyone confirm this? Deltahedron (talk) 06:02, 27 May 2014 (UTC)

An obvious place to look for such information is at his institution:

In Memoriam: Robert Steinberg

Posted on May 27 2014, 12:03 pm

Bob was born on May 25, 1922 in Soroki, Bessarabia, Romania (present day Soroca, Moldavia) and came to settle in Canada with his parents when he was still very young. He was a student of Richard Brauer in Toronto, receiving his Ph. D in 1948 before joining UCLA in 1948 where he stayed till the end. . .

This suggests the news is true :( Rschwieb (talk) 13:25, 28 May 2014 (UTC)

Thanks for that. It was indeed an obvious place to look: so obvious that I had already checked but when I did so the announcement had not yet been posted [18]. (The time stamps make that, well, obvious.) Deltahedron (talk) 20:38, 29 May 2014 (UTC)

List of higher derivatives of the inverse function

I think it would be useful to have an article containing a list of the higher derivatives of the inverse w.r.t. composition of a function from the reals to the reals. We already have Inverse functions and differentiation#Higher derivatives, but that only goes to the third derivative and only shows the derivatives in Leibniz's notation. I think that it would be desirable to go to much higher derivatives (say at least the tenth) and to also show the derivatives in Lagrange's notation.

Does such an article already exist? If not, should we not create it? JRSpriggs (talk) 18:58, 30 May 2014 (UTC)

These higher derivative are rather straightforward to compute with a computer algebra system, either for a specific function or for a general function. The output of such a computation is much more useful than a list in WP, which can hardly be used without copy errors. Therefore, such a list would have a much lower encyclopedic content than an explanation of how one may construct this list with, say, Maple and Mathematica (this is not difficult, but needs some expertise of these software). D.Lazard (talk) 19:34, 30 May 2014 (UTC)

Are there suitable reliable sources to support such an article? Deltahedron (talk) 19:48, 30 May 2014 (UTC)

Not everyone has access to computer algebra systems. Mathematica can output TeX. Why not have it produce the list in Wikipedia-ready format?--agr (talk) 19:56, 30 May 2014 (UTC)

Relationship between mathematics and physics

Relationship between mathematics and physics is a new article that could use work. Michael Hardy (talk) 15:14, 29 May 2014 (UTC)

That article seems very essay-like and unencyclopedic. I don't know what its fate should be. S?awomir Bia?y (talk) 16:37, 29 May 2014 (UTC)

The article has plenty of sources that demonstrate the subject is notable, so I think it's mainly a matter of improving the article. It has only existed for two days - we should help the editor instead of hemorrhaging tags. RockMagnetist (talk) 17:26, 29 May 2014 (UTC)

I didn't say the topic wasn't notable. It would be nice if someone would rewrite the article based on secondary sources. At present, it seems rather like a novel synthesis of primary sources. S?awomir Bia?y (talk) 17:34, 29 May 2014 (UTC)

Sorry, I misunderstood. Usually when someone talks about an article's fate, it's thumb up or down. To me, it seems like a historical survey (with a touch of cheerleading), and it needs more discussion of the philosophical problems. RockMagnetist (talk) 17:43, 29 May 2014 (UTC)

I agree that the article isn't well developed at this point. The vague title begs the question, what should it become? There is already a discussion of the philosophical relation between math and physics (at least from a physicist's point of view) in The Unreasonable Effectiveness of Mathematics in the Natural Sciences and Quasi-empiricism in mathematics. Should the article be more about the historical interplay between mathematical and physical developments? Or should it wax poetic about physical aesthetics and the beauty of mathematically elegant physical theories? (The last is in jest, but is often brought up in popular accounts of math and physics.) --Mark viking (talk) 20:18, 30 May 2014 (UTC)

Jun 2014

Beal's conjecture

The article Beal's conjecture has been the recent target of a crank who refuses to get the point. It probably needs to be watched by more people and/or temporarily semi-protected. S?awomir Bia?y (talk) 18:25, 1 June 2014 (UTC)

AfC submission - 01/06

Draft:Bayesian hierarchical modeling. FoCuSandLeArN (talk) 20:27, 1 June 2014 (UTC)

I just did some very extensive copy-editing on this article. Michael Hardy (talk) 20:47, 3 June 2014 (UTC)

Template:Hardy and Wright

Some time ago I created Template:Hardy and Wright to save myself and others time. It would be nice to be able to add the edition as a parameter, and select the appropriate bibliodata, but unfortunately I'm not fluent in template-speak. Is anyone willing to expand it? The data I have for other editions is

Hardy, G.H.; Wright, E.M. (1979) [1938], An Introduction to the Theory of Numbers (5th ed.), Oxford: Clarendon Press, ISBN 0-19-853171-0, Zbl 0423.10001
Hardy, G.H.; Wright, E.M. (1960) [1938], An Introduction to the Theory of Numbers (4th ed.), Oxford: Clarendon Press, ISBN 0-19-853310-1, Zbl 0086.25803

Deltahedron (talk) 11:32, 1 June 2014 (UTC)

OK I've added an edition parameter so

{{Hardy and Wright}} gives
- Hardy, G. H.; Wright, E. M. (2008) [1938]. An Introduction to the Theory of Numbers. Revised by D. R. Heath-Brown and J. H. Silverman. Foreword by Andrew Wiles. (6th ed.). Oxford: Oxford University Press. ISBN 978-0-19-921986-5. MR 2445243. Zbl 1159.11001.
{{Hardy and Wright|edition=5th}} gives
- Hardy, G. H.; Wright, E. M. (1979) [1938]. An Introduction to the Theory of Numbers (5th ed.). Oxford: Clarendon Press. ISBN 0-19-853171-0. MR 0568909. Zbl 0423.10001.
{{Hardy and Wright|edition=4th}} gives
- Hardy, G. H.; Wright, E. M. (1960) [1938]. An Introduction to the Theory of Numbers (4th ed.). Oxford: Clarendon Press. ISBN 0-19-853310-1. MR 2445243. Zbl 0086.25803.

Hope that OK.--Salix alba (talk): 18:25, 1 June 2014 (UTC)

Thanks! Deltahedron (talk) 19:40, 4 June 2014 (UTC)

AfC submission - 04/06

Draft:Multiple factor analysis. FoCuSandLeArN (talk) 22:47, 4 June 2014 (UTC)

Deletion discussion on Polynomial transformations

The article Polynomial transformations is being discussed for possible deletion at Wikipedia:Articles for deletion/Polynomial transformations. --Bejnar (talk) 00:56, 5 June 2014 (UTC)

Alphabetical order for glossaries

I posted a suggestion at Talk:Glossary of category theory but realised that it would apply more generally. Many but by no means all of the glossary articles in Category:Glossaries of mathematics list entries in alphabetical order. It seems to me that for those ordered by subtopic, the reader who doesn't know exactly what a concept is has to scan the article: the editor who can't fit an entry into an existing subtopic has difficulty placing it. Would uniformly alphabetical order be preferable? Deltahedron (talk) 19:13, 5 June 2014 (UTC)

Alphabetization makes sense to me. For a glossary type of article, it is best to follow the manual of style MOS:GLOSSARIES. In the section MOS:GLOSSARIES#General guidelines for making glossaries, alphabetization is specified. If folks want to create a hierarchical organization of terms, an outline article according to WP:OUTLINE would be a better approach. --Mark viking (talk) 21:22, 5 June 2014 (UTC)

AfC submission - 05/06

Any salvageable content? Draft:Coins in a fountain. FoCuSandLeArN (talk) 14:50, 5 June 2014 (UTC)

Draft:Monotone comparative statics. FoCuSandLeArN (talk) 21:48, 5 June 2014 (UTC)

Draft:FlowSort

Is this concept notable? davidwr/(talk)/(contribs) 05:24, 7 June 2014 (UTC)

No. We just deleted this (via prod) a week ago for the exact reason that it is not notable. --David Eppstein (talk) 05:59, 7 June 2014 (UTC)

Draft:Niels_O._Nygaard

Is this arithmetic Algebraic Geometry researcher notable? Jodi.a.schneider (talk) 19:20, 7 June 2014 (UTC)

Quotient space

Input from mathematics editors may be helpful. See Wikipedia:Redirects for discussion/Log/2014 May 29#Quotient Space. This is a deletion debate for the redirect, but it might also be kept as a redirect to Equivalence class, Quotient space (topology) or something else. The term Quotient space gets more than 100 incoming links from math articles, so it may be important to handle it correctly. EdJohnston (talk) 00:42, 8 June 2014 (UTC)

LaTeX error messages

Is anyone getting odd LaTeX error messages of the form Failed to parse (PNG conversion failed; check for correct installation of latex and dvipng (or dvips + gs + convert))? I'm seeing them on Bott-Samelson resolution, for example, where X_{\overline{w}} seems to work $X_{\overline {w}}$ but

:Z_\overline{w} \to X_\overline{w}

does not

Z_{\overline {w}}\to X_{\overline {w}}

Deltahedron (talk) 08:43, 8 June 2014 (UTC)

That wouldn't work in ordinary latex either, would it? The error message could be more informative though. S?awomir Bia?y (talk) 11:46, 8 June 2014 (UTC)

Ah, I see now. I thought it was a problem with the implementation, rather than an actual error! It should have been :Z_{\overline{w}} \to X_{\overline{w}} giving

Z_{\overline {w}}\to X_{\overline {w}}

of course. Deltahedron (talk) 11:56, 8 June 2014 (UTC)

Relationship with Encyclopedia of Mathematics

The Encyclopedia of Mathematics is now a wiki supported by Springer-Verlag. The text from Springer remains copyrighted to Springer but any new articles added and any changes made to existing articles will come under the Creative Commons Attribution Share-Alike Licence. The articles need work because the formulae in the Springer version now exist only as PNG and the TeX source needs to be recreated. However, every article renewed in this way comes under the new licence, and so is presumably compatible with Wikipedia.

Is there any appetite for an effort to recreate these articles and bring them into Wikipedia? Deltahedron (talk) 20:49, 15 May 2014 (UTC)

How many articles are there? (It is a tempting challenge to write a PNG to LaTeX converter...) YohanN7 (talk) 21:19, 15 May 2014 (UTC)

Eight thousand, I'm told. Deltahedron (talk) 21:24, 15 May 2014 (UTC)

Just for a record, I'm planning to import some of articles from eom to here (cf. my TODO.) Right now, I'm preoccupied with other stuff. -- Taku (talk) 22:07, 15 May 2014 (UTC)

Hi. I was contacted as a volunteer (since I do a lot of work with copyright) and asked to review this. I just wanted to make sure that their license statement isn't misinterpreted. :) New changes come under Creative Commons Attribution Share-Alike but do not change the copyright of the underlying material. So, articles renewed are not autoamtically relicensed - only the new content is. See, for example, http://www.law.cornell.edu/uscode/text/17/103:

The copyright in a compilation or derivative work extends only to the material contributed by the author of such work, as distinguished from the preexisting material employed in the work, and does not imply any exclusive right in the preexisting material. The copyright in such work is independent of, and does not affect or enlarge the scope, duration, ownership, or subsistence of, any copyright protection in the preexisting material.}}

So the original copyright is untouched and the content from the original would not be compatibly licensed, but new material added would be. See also Derivative work. This is consistent with the source's statement that "The original articles from the Encyclopaedia of Mathematics remain copyrighted to Springer but any new articles added and any changes made to existing articles within encyclopediaofmath.org will come under the Creative Commons Attribution Share-Alike License." It doesn't say that the existing articles will come under the Creative Commons license - only that the "changes" will. :) --Moonriddengirl ^(talk) 13:00, 20 May 2014 (UTC)

Strictly speaking it's the licence, not the copyright we need to know about. I agree it's not clear whether modified articles will come entirely under the new licence: perhaps someone will clarify that. Deltahedron (talk) 19:19, 30 May 2014 (UTC)

If I remember correctly, any change to an existing article renders the article to be under cc-by-sa. The logic is like this: licensing doesn't work word-by-word. Say, you added a single word to the original eom article; it's not like that that single word is licensed under cc-by-sa and the rest is not under cc-by-sa. In a case of math, sometimes, contributing a single word can be a substantial contribution (e.g., you added "complete" to metric space.) In other words, by editing an article, you created a "new" article and any new article will come under cc-by-sa. If you like an analogy, it's like editing a picture. You don't license the picture by pixel-by-pixel; that's just absurd. -- Taku (talk) 23:09, 6 June 2014 (UTC)

Is this understanding of the license somehow supportable? It seems rather overly permissive. My understanding would err on the side of caution: as a rule new articles will be covered under the new license, but old articles are not. There might be some exemptions to the latter. For instance, a wholly new paragraph in an older article might be cc-by-sa. But I think it is almost certainly not true that changing a single word makes the entire article fall under a compatible license. S?awomir Bia?y (talk) 12:25, 8 June 2014 (UTC)

List of Italian Mathematicians Question, :Those already on Italian Wikipedia listed here.

I was looking at List of Italian mathematicians to see which ones were red linked and needed articles. I tried Ugo Barbuti by chance, and noticed that, even though he is red in English, he is already listed in the Italian Wikipedia. I decided to check the list to see which ones were available in English and which in Italian. I did the list in two parts, one for the red links and one for the blue, just in case. All of the red links seem to be available in the Italian Wikipedia. Could these all be automatically redirected?

I don't know about other people, but even though my parent language is English, I use Chrome for my browser and right click to translate when I run into any other language. It gives OK English, mostly readable. As a service to visitor could we give them the Italian link for now?

Is there a translation project for these pages? Could a simple page be created for each in English that points to the Italian page and mark it as a stub? What about automatic translation, as poor as it might be, and put a banner at the top to say it was auto translated and needs a human editor? That way if someone finds it through Google or other search, they might be prompted to edit someone they know, or were looking for.

RC711 (talk) 05:16, 13 June 2014 (UTC)

Those Linked Red

Those Linked Blue

Vandalism

I found that Fibonacci was not on this list! I added him. Michael Hardy (talk) 19:23, 13 June 2014 (UTC)

Now I've undone this vandalism from October 2013, which left us with the bizarre spectacle of a "list of Italian mathematicians" that didn't mention the one Italian mathematician that every literate person knows of. Michael Hardy (talk) 19:55, 13 June 2014 (UTC)

A good list of links that needs to be in a more prominent place

As you know, Wikipedia is notorious for long lists of little importance. My problem is just the opposite. This excellent (and mercifully short) list,

Linear_equation#Algebraic_equations

is buried on a not-so relevant page. I think it belongs on Algebraic equation or perhaps Algebraic expression. Perhaps someone should write a template or something?--guyvan52 (talk) 14:58, 8 June 2014 (UTC)

I moved the list to Algebraic equation, keeping a few linear equation links, and adding a link to Algebraic equation. I think it looks better now. I also reordered the links in order of usage, to my best guess. Hope that works for you. I will let you tackle the templates. But I think it is fixed for now.RC711 (talk) 16:45, 14 June 2014 (UTC)

Random Math Article link Broken

In this article there is a link for a random math article. It points to http://tools.wmflabs.org/jitse-bot/rpim but seems to be broken. I would like to look at random articles in a general category like mathematics. I presume it is looking at the list of articles and selecting from that. Can that be done for any subject?

RC711 (talk) 03:39, 13 June 2014 (UTC)

See Random page in category - Wikipedia, the free encyclopedia.

--Wavelength (talk) 19:25, 13 June 2014 (UTC)

Apparently this special page selects a random article in the specified category, not in the subcategories. Called on "mathematics" the random choice is done among 18 categories and 13 articles, that is 31 items. Absolutely not useful! D.Lazard (talk) 20:28, 13 June 2014 (UTC)

Oh. Thanks for the details. I was being hopeful that it would pick among the some 30,000 math articles in the list of math articles, or among the categories and drill down. I would like a search on Wikipedia to find pages in any broad topic. Like a random page about chemistry, or one about birds, or one about snakes, or one about European cities - something like that. If we can define lists of pages with common themes, then it is simply a matter of picking a random number and then looking for that index to the particular list. Mathematics is the only subject I found with a master list of pages like this. I have been trying to drill down in category trees from a top page like Category:Mathematics or Category:Science to find all the child pages, working through all the subcategories. Work in progress.RC711 (talk) 20:50, 13 June 2014 (UTC)

At any rate, it would be nice to get Random mathematics article back up. Perhaps someone should ping Jitse? S?awomir Bia?y (talk) 21:44, 13 June 2014 (UTC)

I wrote a note on his talk page User_talk:Jitse_Niesen, but have not heard back yet.RC711 (talk) 22:46, 13 June 2014 (UTC)

Thanks for the note. It seems the correct link is now http://tools.wmflabs.org/jitse-bot/rpim.py . I fixed this in the template included in the WikiProject page. -- Jitse Niesen (talk) 14:36, 15 June 2014 (UTC)

A challenge from Jimbo Wales

User:Jimbo Wales posted the following in response to a question about WMF plans for mathematics software development:

It might be helpful to give more specific details. "png is still standard" is a tantalizing clue but... what do you recommend instead? What does the dream solution look like? What is currently state of the art on the web in terms of math editing and rendering software? The last time I looked into this (admittedly quite some time ago) what most math editors wanted was LaTex support, and rendering to png was a reasonable way to render. So, that's what we have now. What would math editors prefer today? I'm happy to help but it would be delicious if I had an NPOV summary of the current state of the art, how it compares with what we support, and some basic first step explanations of what the steps are to get from where we are to where we want to be, what help we might be able to engage from the broader math community, and what engineering costs we might expect to shoulder on our end. We have a new CEO now, specifically chosen for tech/product focus, and so a lot of things will be up for discussion over the next year or two.--Jimbo Wales (talk) 20:08, 6 May 2014 (UTC)

Perhaps participants here may care to work on a response. Deltahedron (talk) 20:50, 6 May 2014 (UTC)

What I want is mathjax + fast rendering. It isn't problematic on other sites (MathOverflow, MathSciNet, arXiv, etc) and has become a de facto standard among professional mathematics sites. So why does it have to be so difficult here? --David Eppstein (talk) 21:11, 6 May 2014 (UTC)

What David said. It's technologically possible if there is will. (Everything is possible with will?) -- Taku (talk) 21:38, 6 May 2014 (UTC)

That would be a significant improvement, but unfortunately it doesn't solve the serif/sans problem. I'm not sure there actually is a solution to that, aside from a very strong recommendation that if you can in any reasonable way avoid it, even if it requires significant variation from your ideal word order, just don't put mathematics into running text.

I don't want the perfect to be the enemy of the good here, but I also don't want people to think, "oh, as soon as MathJax comes along, we'll be just fine". --Trovatore (talk) 21:17, 6 May 2014 (UTC)

Just out of curiosity does mathjax support inline vs displayed rendering? Thenub314 (talk) 21:23, 6 May 2014 (UTC)

Yes. In the default parameters for mathjax they are distinguished by using $ ... $ for inline, and \[ ... \] or $$ ... $$ for display (they don't automatically enable $ ... $ delimiters because dollar signs have other uses, but the delimiters are easy to change). See e.g. http://docs.mathjax.org/en/latest/start.html. On web pages outside Wikipedia it's extremely easy to use mathjax -- just add a couple of lines to the header of your web page, copied from the docs that I linked, and go. --David Eppstein (talk) 21:49, 6 May 2014 (UTC)

It may also be worth pointing out that the community does not want or need a WYSIWYG formula editor. Most new editors of mathematics already know LaTeX, but may not know wiki syntax. I realize that a more user-friendly interface with the LaTeX source is now what visual editor seems to offer, but it may be worth emphasizing at what point feature development on that part of the project should stop. S?awomir Bia?y (talk) 21:40, 6 May 2014 (UTC)

Yes, I think this is very important. WYSIWIG editors are less flexible and more cumbersome than TeX. Honestly I don't think it's unreasonable to ask that anyone who wants to enter equations learn some basic TeX - it's standard and not hard. Ozob (talk) 01:59, 7 May 2014 (UTC)

I am not up to speed enough yet to know what the community may or may not want regarding a WYSIWYG formula editor, but in principle I agree with you that such a thing is not nearly as high a priority as making sure that proficient math editors are appropriately supported with the latest and greatest, subject of course to the path forward being cost effective and acknowledging that nothing is likely to be perfect anytime soon. But if there are things that can be done to make significant progress for you all, relatively painlessly, then I think that's an obvious thing to do.--Jimbo Wales (talk) 02:00, 7 May 2014 (UTC)

I wouldn't rule out WYSIWYG editors. There's one I have that works pretty well for simple equations, the one built into Apple's Grapher (in the Utilities folder on any modern Mac). You can do a suprising amount with it. It's keyboard driven rather than mouse, so you're typing and using shortcuts to place things rather than manually placing them but that works well as it means the app does all the layout, LaTeX like. There's also a toolbar for inserting things you don't know how to type, much like our edittools.

I would question the assertion that most new math editors know LaTeX. I didn't pick it up while doing maths at school or as an undergraduate, only later, and I imagine this is fairly common at undergraduate level, where at least in maths your main tasks are to learn things to pass exams. An equation editor though would help non-mathematicans more; right now you need LaTeX for things like matrices, all but the simplest of formulae, even when they appear in non-maths articles.--JohnBlackburne^words_deeds 02:33, 7 May 2014 (UTC)

Hello, Jimbo --- interesting to see you posting here. To see examples of how MathJax works, look at math.stackexchange.com . It works really well. It matches the size of the surrounding text and it doesn't get misaligned the way inline math notation on Wikipedia often does. (However, on that site, one sees some amazingly unskilled uses of it. I marvel at the fact that it is humanly possible to acquire such extraordinary unskillfulness.) Michael Hardy (talk) 03:20, 7 May 2014 (UTC)

I agree with you that most new math editors probably do not know any TeX. Despite that, I think it is reasonable to ask them to learn a little. Learning basic TeX is like learning basic wiki markup. It's nice to have an editor where you can push a button to turn on italics, but learning to insert two single quotes is not difficult. Similarly, learning to enter \frac{1}{2} to generate the fraction

{\frac {1}{2}}

is not hard. Nor is learning to enter \times if you want a times symbol

\times

. And that's as much as many people will need and as far as many of them will get with TeX. In a perfect world, it would be nice if there were a WYSIWIG editor because it would lower the bar to editing. But the bar is already pretty low, the effort involved in creating a WYSIWIG equation editor is pretty high, and ultimately the mathematics is likely to be translated into TeX for rendering anyway. Ozob (talk) 03:44, 7 May 2014 (UTC)

The counter-argument to that is the visual editor exists, at least in part, so editors don't have to learn wikimarkup. Even without the visual editor you can get a lot done with no experience using the toolbar above the edit window, to insert bold, italic and other formatting so you don't need to learn their markup, and making it easy to learn as you go along because it shows you how to do it.

But hitting the '?n' button just gives you <math>Insert formula here</math>, with no guidance, no example(s) to learn from, not even a link to a help page. There's a limit to what could be done as 'Insert formula here' could be replaced with a wide variety of things, while bold, italic etc. only work one way. But this is also a motivation for doing more as even if an editor learns some equation editing, such as how to make a fraction, it doesn't mean they know other LaTeX such as how to make an integral.--JohnBlackburne^words_deeds 10:36, 7 May 2014 (UTC)

I think we have two essentially unrelated problems, and that these should be handled independently: rendering from the markup (presently TeX), and capture. Rendering currently is a major headache/obstacle (very slow MathJax, sizing and alignment of PNG, with some font complaints), and this I find really puzzling. Capture relates to interaction with the editor, and I think that here we should stick to an editor-visible and -modifiable markup. A WYSIWYG editor and/or toolbar can be treated as separate exercise. If we separate these two points (which only involves a decision on what markup to use), and even if we deal with only the rendering problem initially, we will have a major improvement. Treating them as intertwined may contribute to continued stagnation. --Quondum 11:10, 7 May 2014 (UTC)

A problem, which is related to both rendering and editing: In most article the mathematical variables looks differently when displayed (serif italic) and inline (sanserif italic). The use of {{math}} allows inline serif, but few editors know it, and those who know it are often too lazy to use it (14 characters to insert a single variable, as {{math}} does not imply italic). A simple solution could be to introduce $a$ as a shorthand for {{math|''a''}}, and similarly for more complicated formulas that may be rendered in html. D.Lazard (talk) 11:43, 7 May 2014 (UTC)

For myself I see the slowness as something that will be fixed eventually by the speed of processors and in the not too distant future, so if there is a problem it really is what should we do about low specced smartphones used in the middle of beyond by poor people? That problem will be around for a while at least and it is one of the aims of Wikipedia to disseminate knowledge widely. Should we just keep pngs for that for the moment? As to having a visual editor for entering maths I would like to see one implemented and the main thing it should do for starters is not ruin a formula if they display it and a small bit is edited - i.e. that it be robust and not generate a huge pile of rubbish just to get the same display. After that it should be easy to use, and after that it should be possible to put in anything (rather than just cope with letting through anything). There's lots of simple maths around where people can contribute who've never heard of TeX. And I agree it should be easy to mark variables in the text as maths symbols. I would prefer them to be italic serif even in non serif text, but if we can have a user CSS style set which dictates that it would solve such problems for like them to match the surrounding text. It may sound trivial to some but there are people who find the mismatch quite annoying. Dmcq (talk) 12:18, 7 May 2014 (UTC)

Huh? Serif/sans is rendering and not editing, and as per Dmcq can be treated via individual preferences; treat it is a third independent thing if you wish. Adding a shorthand alternative writeup language is a peripheral problem, not part of the fundamental one; it could be added at any time. Writing off MathJax's slowness (and frequent complete failure to render!) as "it's fine - we'll just wait until more processor power is on tap" doesn't fly for a number of reasons. Let's focus on fixing what is really holding us back. --Quondum 13:42, 7 May 2014 (UTC)

My two cents is that whatever is chosen, please keep it to one choice, and make that choice work, and work well. This includes ease of use, visual appearance and performance. I don't belong to the category of people that believes performance isn't an issue "since future CPU's and internet connections will be faster". If you manage to use up CPU power that is enough to numerically solve Einsteins field equations for 17 colliding black holes when displaying f(x) = x, then something is fundamentally wrong. Such software is simply not sustainable/maintainable in the long run. More importantly, it is very difficult to further develop such software because it is deemed to be a total mess (spaghetti code).

POV: WYSIWYG editors are nice up to a point. But think about it. What would you really prefer in the long run, MS Word or a edge-of-the-wedge LaTeX editor? Not saying that building wrappers to simplify for new users is wrong/bad, but please let advanced users have access to the "core" of whatever becomes chosen. This is not the same as having multiple edit options with competing editors. YohanN7 (talk) 16:25, 7 May 2014 (UTC)

Besides obvious bug fixes and performance improvement, what I want are (1) the support for commutative diagrams (I've heard the topology coverage here is less satisfactory than, say, algebra one and this might explain this.) (2) the support for simple figure drawing like circles and triangles. In terms of latex, both can be achieved by installing appropriate packages and thus there shouldn't be a technological hurdle. One more thing: the ability to use mathcal fonts that became standard among topologists such as J. Lurie. (I'm thinking of mathcal O or L that are not default ones; I can elaborate if I'm not making sense.) -- Taku (talk) 00:06, 9 May 2014 (UTC)

Regarding fonts, I believe you're thinking of the package mathrsfs. Ozob (talk) 01:18, 9 May 2014 (UTC)

I don't think so. This is what I had in mind. (I needed a PC to upload the pic.) -- Taku (talk) 10:49, 12 May 2014 (UTC)

That's overwhelmingly similar to the standard \mathcal (for reference:

{\mathcal {O}}

{\mathcal {L}}

). A basic typographic principle is to not use too many fonts in the same work. According to that principle, either all uses of \mathcal should use the font you've suggested (whatever it is), or that font should not be used anywhere on Wikipedia. That's a vastly more invasive change than you seem to have in mind. I'm not convinced it's worth it, either; what about this font do you find so enticing? Ozob (talk) 02:30, 13 May 2014 (UTC)

Similar but different, which is not a contradiction :) I just wish it were an option (not changing the standard one.) -- Taku (talk) 21:19, 13 May 2014 (UTC)

It seems to me obvious, but perhaps worth spelling out, that the only viable form of internal representation of mathematics today is some form of LaTeX markup. A graphical interface or formula editor that can work with underlying markup is important, especially if VE takes off, but for some applications direct access to the markup will continue to be essential. Deltahedron (talk) 21:25, 10 May 2014 (UTC)

Yes, agreed. What is less obvious to most is the resultant separability of the various aspects of maths on WP. I would suggest that WP's greatest benefit will come from fixing the rendering problem, and treating everything else as secondary: get MathJax working, or find a replacement that works. Even the exact choice of underlying markup is not an immediate issue. If there is appetite for more other areas such as graphical editing interface, these can happen later or separately in parallel. Whatever happens, sort out the rendering as a priority. --Quondum 22:19, 10 May 2014 (UTC)

Again in terms of the original challenge, it might be useful to list sites using LaTeX + MathJax, LaTeX + PNG, and others. I know off-hand that Encyclopedia of Mathematics is converting from LaTeX + PNG to LaTeX + MathJax; MathOverflow uses MathJax, as does math.stackexchange.com -- any more? Deltahedron (talk) 22:38, 10 May 2014 (UTC)

As I already noted in the first reply in this thread, MathSciNet and arXiv also use MathJax. In the case of arXiv, it's for the display of the abstracts of preprints, after previously only allowing ascii text; the papers themselves are available in postscript or pdf, but generally not html. I don't remember what MathSciNet was using before MathJax, but LaTeX+PNG seems likely. I just checked the All-Russian Mathematical Portal, and they're also using MathJax. On the other hand, Dagstuhl still seems to be limited to ASCII text for the abstracts of their publications. --David Eppstein (talk) 22:54, 10 May 2014 (UTC)

It does not seem as though there is any technical difficulty (i.e., presumably other sites have MathJax working). If we can set down a clearcut objective of, say, getting MathJax rendering of LaTeX working within stated constraints (performance, platforms, development timescales), the rest of Jimbo's ask should not be too difficult to quantify (for those in touch with it). I think that the only thing really lacking is a the setting of a clearcut, clearly attainable objective, and I'm hoping that this would not be difficult if it is judiciously limited. --Quondum 23:33, 10 May 2014 (UTC)

If I remember correctly, MathSciNet used to use straight ASCII; you had to render the TeX in your head. Ozob (talk) 23:43, 10 May 2014 (UTC)

ZMATH used to have TeX and MathML rendering options but seems to have to reverted to showing scans of the older pages and very badly converted HTML for more recent, the latter in particular being almost useless. Deltahedron (talk) 16:20, 11 May 2014 (UTC)

This is of course not a specifically English-language issue. Perhaps editors with better language skills than mine would like to consider posting a corresponding message at the other language projects. If not, I'll have a go at de:Portal Diskussion:Mathematik and fr:Projet:Mathématiques/Le Thé byut the results may not be pretty. Deltahedron (talk) 16:16, 11 May 2014 (UTC)

You can post in English on the German math discussion page, no problem there. Best wishes, --Quartl (talk) 18:58, 11 May 2014 (UTC)

Done! Deltahedron (talk) 19:10, 11 May 2014 (UTC)

Thanks for the link on fr:Projet:Mathématiques/Le Thé. MathJax is a really useful tool, I can't deny that (and I'm glad to use it). But

it can be slow on webpages with lots of formula (e.g. on Wikipedia)
it requires JavaScript (as far as I know)
just try to copy-paste a paragraph with math formula inside...

Compare with such a page (sorry, it's French). I cannot pretend to get a perfect rendering on every browser, but you can read it without JS (the real tool is in CSS), and copy-paste gives you a valid expression on most simple cases. The gap is a converter from latex (possibly inside wikicode) to HTML. I've not written it yet, but anybody can do it, since all these files are under CC-BY-SA license. Of course, there is still work to do (management of graphics), but in my humble opinion this path seems more fitting to mathematics on the web than MathJax machinery. Ambigraphe 19:01, 12 May 2014 (UTC)

Woo-hoo! Now that (French) page renders fast and without problems on my browser. This is what we should have on WP. --Quondum 03:09, 13 May 2014 (UTC)

And on my very old-fashioned laptop which struggles with the current MathJax on WP and on EoM. Congratulations to the authors. I just had a somewhat disappointing conversation with User:Mdennis_(WMF) in which she she did mention that she could help with the WMF "grants programs, if you want to seek funding for development of mathematics software" and that might be of interest in developing this further. Deltahedron (talk) 06:38, 13 May 2014 (UTC)

I share your disappointment at the response in that conversation. I would go further, and suggest that I am appalled at the apparently purposeful disengagement and evident lack of understanding of where a little involved coordination and direction could make all the difference to existing efforts that have been stalling. We all understand that with Brownian motion a particle usually gets somewhere (unplanned), but as the WP community gets larger, this is like assuming that undirected local crowd behaviour is a useful governing principle. --Quondum 14:04, 13 May 2014 (UTC)

Yay, that French thingie! Now I don't know whether its my crappy internet connection or the rendering that takes 0.5 seconds. That page is easily several seconds of work for (our) MathJax, at least on my system. (After playing around some more, rendering appears to take 0 seconds within human approximation, just as it is supposed to.) YohanN7 (talk) 15:35, 13 May 2014 (UTC)

Yet another venue for this discussion: mw:Talk:Wikimedia_Engineering/2014-15_Goals#Mathematics_rendering_and_editing, pointed out by User:Mdennis (WMF). Deltahedron (talk) 15:48, 14 June 2014 (UTC)

Parallel discussion

Since the discussion that started this has been removed from User talk:Jimbo Wales, I thought it worth making a copy for reference for editors who came here from another direction. Deltahedron (talk) 21:16, 15 May 2014 (UTC)

The notice below saying "This discussion has been closed" refer to the discussion below, seen when you click on "show", not to the discussion above. Michael Hardy (talk) 15:35, 17 May 2014 (UTC)

Summary

Would anyone like to summarise? I will if no-one else does, but I have definite opinions. Deltahedron (talk) 06:05, 27 May 2014 (UTC)

OK, here goes. I suggest comments go in the next section, and that any edits to the draft text, unless quite trivial, be accompanied by a comment. Deltahedron (talk) 20:13, 6 June 2014 (UTC)

I've incorporated some comments into the text. If no-one objects I'll take it back to WMF as the Project's view at the weekend. Deltahedron (talk) 20:10, 19 June 2014 (UTC)

Now posted to User_talk:Jimbo_Wales#WMF_plans_for_mathematics_II. Deltahedron (talk) 20:06, 21 June 2014 (UTC)

Background

About 1% of Wikipedia's 4.5 million articles are assessed as being in "Mathematics and Logic". Probably a similar number are in theoretical physics and in computer science. So in about a hundred thousand articles, the ability to render mathematics is indispensible to the reader: the ability to write and edit mathematics is indispensible to the author and editor.

Currently the predominant mathematics markup system in all forms of document preparation is some flavour of LaTeX. It may be presumed that any serious mathematics content contributor will be thoroughly familiar with LaTeX. LaTeX is rendered on web pages in a variety of ways: currently Wikipedia uses two of the more popular methods, rendering formulae as PNG images and rendering dynamically using MathJax. There are deficiencies in the current implementation of each of these methods.

The stability and usefulness of current mathematics rendering is reduced by the following

Incremental development of reader and editor interfaces is apt to degrade the reader or editor experience without warning.
Major changes in editor interfaces, such as the introduction of Wikipedia:VisualEditor and Wikipedia:Flow, may be radically incompatible with existing LaTeX markup practices.
Effort to support mathematics editing and rendering comes entirely from the volunteer community. Currently one volunteer is working on mathematics rendering, and support for mathematics editing in VE consisted of one GSoC summer volunteer.

WMF planning

We are reliably informed that WMF has no plans for development of mathematics rendering and editing. That is, there is no plan to coordinate volunteer effort; no plan to integrate volunteer effort into existing products; no plan to ensure the sustainability of mathematics rendering and editing through major changes to the software and user interface.

As a consequence of the lack of plans, there is no allocation of WMF developer effort to the maintenance, sustainability or enhancement of mathematics rendering and editing. It is assumed that volunteer developers will undertake any tasks that are necessary, even though there is no plan to coordinate those efforts.

It is reasonable to say that there is considerable expertise and experience in mathematics rendering and editing in the existing editor communities. There is no explicit mechanism to capture that experience and make use of it in planning, development or review. Such efforts as have been made to do so are limited in extent and driven by the user community rather than WMF. The role of Community Advocates in linking the editor community and WMF planning and developers in this context has not been effective.

Suggestions

General

WMF planning address the issue of development of mathematics and other complex rendering markup and editing components.
WMF liaise actively and effectively with existing editor and reader communities in (1).
WMF draw up roadmap for development of complex rendering and editing.
WMF liaise actively and effectively with volunteer developer communities to determine required frameworks and work packages.
WMF allocate funds and resources to support work packages.

Specific

Mathematics rendering to be based on MathJax as principal vehicle, with efficiency and resources issues resolved on a wide variety of platforms.
LaTeX markup retained as principal mode of editing mathematics text with concomitant option to directly edit at the wikitext markup level.
WMF establish a workflow for further development and deployment of the math extension, using the https://www.mediawiki.org/wiki/Extension:Math/Roadmap page to coordinate the development process.
WMF designate a fixed contact person at WMF that cares about math related questions and a brief to maintain regular and frequent contact with volunteer community.

Short-term

Fix MathSource mode is currently disabled: see [23] which resolves this issue.
Fix issues with experimental mathoid (MathML + SVG) support on the Beta Cluster.

Comments on draft

Please comment here. Deltahedron (talk) 20:13, 6 June 2014 (UTC)

Excellent summary. I have one small criticism that point number two under "Specific" is not likely to make much sense to someone reading the summary who is not already familiar with the details of past discussions. I think this should be stated more plainly. S?awomir Bia?y (talk) 10:23, 7 June 2014 (UTC)

workflow: From my perspective the most important thing is to establish a workflow for further development and deployment of the math extension. There are two volunteers Frédéric Wang and myself actively working on the Math extension. From WMF side the Visual Editor team takes care of the Visual Editor related aspects. For Frédéric and me the main problem is that we have no fixed contact person at WMF that cares about math related questions. I think a very brief weekly Skype meeting with a fixed contact person would eliminate most of the problems. This would eliminate most of the randomness involved in the current development process.
roadmap: I tried heavily to promote the https://www.mediawiki.org/wiki/Extension:Math/Roadmap page to have a more coordinated development process. Looking at the history indicates that I have changed my username. If anybody here is willing to contribute to the roadmap pleas give me a signal and I'll update the page. Otherwise I see no need to update this page for my own use only.
source rendering mode: I apologize that the MathSource mode is currently disabled. There is a fix at https://gerrit.wikimedia.org/r/#/c/139439/ which resolves this issue. As soon as this is backported by some WMF employee the source rending mode will be back.
MathML support: We manged to have experimental mathoid (MathML + SVG) support to the master branch. It works well on private wiki installation, but on the Beta Cluster only the SVG is displayed correctly. The MathML elements like <mo><mi>... are removed for some reason. If anyone has an idea why this happens I'd be very happy about comments either here, at my user talk page or at the bug report at https://bugzilla.wikimedia.org/show_bug.cgi?id=66495. (I'll try to visit this page more often); --Physikerwelt (talk) 17:38, 14 June 2014 (UTC)

Preference ranking organization method for enrichment evaluation

Is this topic notable? If so, it could use an assessment. If not, it could use a trip to WP:AFD. davidwr/(talk)/(contribs) 05:23, 7 June 2014 (UTC)

Sounds like nonsense, possibly a hoax. JRSpriggs (talk) 05:34, 7 June 2014 (UTC)

It is certainly a thing that exists, I.e., there are websites about it easily findable by Google. I don't think that mathematicians are the best-possible evaluators of the content: it's mathematical but not mathematics. I don't know what sort of sources would be most likely to establish notability -- management journals? --JBL (talk) 13:23, 7 June 2014 (UTC)

Exactly so: mathematical but not mathematics. The refs in the article, aren't they the needed sources? Boris Tsirelson (talk) 14:59, 7 June 2014 (UTC)

A cause for concern is that the main contributors to the article are Qhayez (talk · contribs), Bmaresc (talk · contribs) and Hugosbento (talk · contribs), all of whom have contributed exclusively or almost exclusively to this topic: and the linked web site shows that Prof B. Mareschal, Quantin Hayez and Hugo S. Bento Pereira are associated with this topic and the related company D-SIGHT. Deltahedron (talk) 15:45, 7 June 2014 (UTC)

It seems like a thing that exists, yes. But one has to wade through two thirds of the article to find out what kind of thing it even is. Perhaps a few sentences should be added to the lead about what the subject of the article actually is? S?awomir Bia?y (talk) 16:27, 7 June 2014 (UTC)

There are a lot of fads in business administration which amount to a senseless application of mathematics. JRSpriggs (talk) 11:37, 8 June 2014 (UTC)

Thanks everybody who participated. I started a new discussion at Wikipedia talk:WikiProject Business#Preference ranking organization method for enrichment evaluation, with a backlink to here. Please continue the discussion over there. davidwr/(talk)/(contribs) 22:31, 21 June 2014 (UTC)

Master stability of the synchronized state on AfD

See this discussion:Wikipedia:Articles_for_deletion/Master_stability_of_the_synchronized_state Michael Hardy (talk) 21:06, 22 June 2014 (UTC)

AfC submission - 22/06

Draft:Rainbow coloring. FoCuSandLeArN (talk) 13:41, 22 June 2014 (UTC)

This seems to be notable. ZMATH gives 10 articles on "rainbow colouring" and 27 for "rainbow coloring". Deltahedron (talk) 16:50, 22 June 2014 (UTC)

And how many of those relate to the particular concept that is the subject of the article? --JBL (talk) 23:15, 22 June 2014 (UTC)

Enough to rebut the assertion that "there is no indication that it has been used elsewhere", I suggest. Deltahedron (talk) 06:17, 23 June 2014 (UTC)

Leaflet for wikiproject Mathematics at Wikimania 2014 (updated version)

Please note: This is an updated version of a previous post that I made.

Hi all,

My name is Adi Khajuria and I am helping out with Wikimania 2014 in London.

One of our initiatives is to create leaflets to increase the discoverability of various wikimedia projects, and showcase the breadth of activity within wikimedia. Any kind of project can have a physical paper leaflet designed - for free - as a tool to help recruit new contributors. These leaflets will be printed at Wikimania 2014, and the designs can be re-used in the future at other events and locations.

This is particularly aimed at highlighting less discoverable but successful projects, e.g:

o Active Wikiprojects: Wikiproject Medicine, WikiProject Video Games, Wikiproject Film

o Tech projects/Tools, which may be looking for either users or developers.

o Less known major projects: Wikinews, Wikidata, Wikivoyage, etc.

o Wiki Loves Parliaments, Wiki Loves Monuments, Wiki Loves ____

o Wikimedia thematic organisations, Wikiwomen's Collaborative, The Signpost

The deadline for submissions is 1st July 2014

For more information or to sign up for one for your project, go to:

Project leaflets
Adikhajuria (talk) 17:03, 25 June 2014 (UTC)

Constructibility (disambiguation)

I've just done some work on Constructibility, a disambiguation page. Perhaps others can contribute something as well. Michael Hardy (talk) 22:14, 25 June 2014 (UTC)

Dao six-point circle

Deletion of Dao six-point circle is being discussed. Possibly OR? Michael Hardy (talk) 06:12, 22 June 2014 (UTC)

One of the sources, ETC, is reliable for this sort of thing, but (like OEIS for integer sequences) not very selective. So I don't think OR is quite the right description, but whether it's notable is a different question. --David Eppstein (talk) 06:19, 22 June 2014 (UTC)

If the ETC and cut-the-knot have picked it up, it is has seen some review and the ETC is considered reliable, so from that perspective no OR. It seems to be just a very recent result in a niche area of mathematics. There might be a notability issue though, since the electronic version of the ETC (contrary to the printed book) contains a few thousand newer results in elementary geometry and not all of them might be considered notable on their own.--Kmhkmh (talk) 06:52, 22 June 2014 (UTC)

Surely a nuanced version of the notability requirement is needed for cases like this, especially in mathematics? Where the result can be considered to be established and valid, and not covered by a more general result, regardless of its publication and review status, it seems like arguing for deletion would be wikilawyering. I realize that this places quite a burden of evaluation on the editors, but in a sense this burden exists in all cases. --Quondum 14:48, 22 June 2014 (UTC)

Is there a case for an article on List of triangle centres which could include short, referenced, definitions such as this? Deltahedron (talk) 15:50, 22 June 2014 (UTC)

Currently such theorems/result could still be incorporated as partial content in survey/summary articles like suggested List of triangle centres (note however the ETC contains a few thousand, the book version around 400 iirc). I have no objection against a more nuanced version, however there needs to an effective method for blocking unwanted content as their is potential danger that people will try to publish correct/established directly in WP (instead of elsewhere). Also one needs to keep in mind that there is an infinite number of correct but not-notable mathematical statements/theorems. While there are case where most editors would agree it is ok to have them in WP (despite officially failing the current notability), there will be probably even more where editors disagree. In particular for the latter group a more nuanced policy should provide an somewhat objective criteria for the decision about the inclusion in WP.--Kmhkmh (talk) 16:31, 22 June 2014 (UTC)

It is true that there are infinitely many theorems, but the criterion for inclusion in a list is the same as for any other content: verifiability in an independent reliable source. Deltahedron (talk) 16:46, 22 June 2014 (UTC)

The problem here is not WP:V, nor WP:RS, but notability. I agree with Kmhkmh: that we need better criteria for deciding notability for results that have been reliably published and whose correctness is established. I would suggest something. One could considered as non-notable a result that has not been used in secondary sources. Also, I consider that an article is WP:ORPHAN in nature if it may be naturally linked to only in lists or in "See also" sections (this is the case for this article, and also for the draft linked to in next section). Therefore, my suggestion is, in the case where notability is dubious, to consider as non-notable a notion or a result that is a quasi-orphan as it cannot be linked to from the text of other WP articles, without ad hoc expansion of these articles. D.Lazard (talk) 17:11, 22 June 2014 (UTC)

Notability is the criterion for an article, but not for the content of an article or a list. Deltahedron (talk) 17:17, 22 June 2014 (UTC)

A possible way to nuance to notability (especially for content rather than articles) is: "Does it have reference value?" I think this ties in with D.Lazard's perspective: his suggestion gives ways of answering the question that I've given here. --Quondum 17:18, 22 June 2014 (UTC)

Indeed: if a reader is likely to want information on the subject then the question of links from other articles is not so important. Deltahedron (talk) 17:21, 22 June 2014 (UTC)

As far as notability is concerned, the German Wikipedia for instance considers any (math) subject notable, that has been published in established journal or a properly published textbook. However that approach may not quite comprise the nuance Quondum is asking for above. Nevertheless i think it is good rule of thumb, which seems to be implicitly followed in en.wp as well anyhow.--Kmhkmh (talk) 18:07, 22 June 2014 (UTC)

I recheck ENCYCLOPEDIA OF TRIANGLE CENTERS part 4 http://faculty.evansville.edu/ck6/encyclopedia/ETCPart4.html, In 840 triangle centers, Using Ctrl+F search returns 52 hits for "the circle" --Eightcirclestheorem (talk) 05:46, 26 June 2014 (UTC), And has only 3 triangle centers wich center of the circle(named after who discovered) --Eightcirclestheorem (talk) 01:39, 26 June 2014 (UTC)

Dear Admin,

Please help me restore Dao six point circle again, because the circle will appear in a journal in next month (October 2014)--Eightcirclestheorem (talk) 08:18, 26 September 2014 (UTC)

Relevant RfC:

Wikipedia:Village_pump_(proposals)#RFC:_Naming_of_one_and_two_digit_numbers_and_years PamD 14:21, 27 June 2014 (UTC)

Links to Master stability function

Which articles ought to link to the now orphaned article titled Master stability function? Michael Hardy (talk) 01:13, 28 June 2014 (UTC)

Dao-Moses circle

Notability of Dao-Moses circle might bear some discussion. The concepts is mentioned in a reliable but quite inclusive source. Michael Hardy (talk) 20:23, 22 June 2014 (UTC)

How does the case of this article differ from that of Dao six-point circle, already being discussed? Deltahedron (talk) 21:08, 22 June 2014 (UTC)

I don't know; I haven't looked that closely. Michael Hardy (talk) 17:18, 23 June 2014 (UTC)

Dao six-point circle was recently deleted following a discussion. It seems to me that this should also be deleted, for essentially the same reasons. S?awomir Bia?y (talk) 12:17, 28 June 2014 (UTC)

Nominated for deletion: Wikipedia:Articles for deletion/Dao-Moses circle.--JohnBlackburne^words_deeds 12:31, 28 June 2014 (UTC)

Markushevich basis

Perhaps the new article titled Markushevich basis would benefit from having one or more additional contributors. Michael Hardy (talk) 20:14, 29 June 2014 (UTC)

Draft:Monotone comparative statics

Please will someone who can speak mathematics review this article? Fiddle Faddle 08:53, 30 June 2014 (UTC)

Jul 2014

Jacobi method

I was wondering if we have an article on Jacobi iterative method ? I noticed a new variant of it scheduled relaxation Jacobi method was recently published doi:10.1016/j.jcp.2014.06.010 -- 65.94.171.126 (talk) 06:01, 2 July 2014 (UTC)

We do have an article on the Jacobi method, and a new section on the recent development has already been created. FireflySixtySeven (talk) 06:44, 2 July 2014 (UTC)

Thanks -- 65.94.171.126 (talk) 07:28, 2 July 2014 (UTC)

Geometric Poisson distribution

Someone more knowledgeable about probability theory may want to check out the new Geometric Poisson distribution article. As I explained on the talk page, I suspect the current version of the article covers a non-notable distribution which shares a name with a vastly more notable one, the latter of which is also called the Pólya-Aeppli distribution. We should rewrite the article so it covers the notable topic. Huon (talk) 17:21, 3 July 2014 (UTC)

AfC submission - 04/07

Draft:Deformation tensor. FoCuSandLeArN (talk) 13:46, 4 July 2014 (UTC)

Quotient space (2)

I have changed Quotient Space (with capital initials) from a redirect to Equivalence class to a redirect to Quotient space (lower-case "s") and changed the latter to a disambiguation page, so far with only two main links and a "see also" link. So:

The disambiguation page would probably benefit from more work; and
Lots of pages link to the new disambiguation page. Those need to get appropriatedly directed.

Michael Hardy (talk) 18:38, 12 June 2014 (UTC)

It seems to me that Quotient space should be an article in its own right, not only a disambiguation page. The concept clearly applies (under the name "quotient") throughout abstract algebra, and seems amenable to a general definition. It would naturally link to the articles for the concept as applied in subdisciplines, for example Quotient group, Quotient ring, Quotient vector space, Quotient semigroup, quotient set ... and the like. This is exemplified by the link to Quotient space (disambiguation) in Isomorphism that is a reference to the more-inclusive concept (but not to all the links in the current disambiguation page), when none of the individual articles will do as a target. Quotient space (disambiguation) would then become a disambiguation page rather than a redirect. --Quondum 19:24, 22 June 2014 (UTC)

On review, perhaps that article is Equivalence class, but somehow with reference to the structure-preserving concept, is that the right name? --Quondum 19:42, 22 June 2014 (UTC)

I added a section to equivalence class, trying to cover enough for a reader to understand both generalized and particular meanings and uses of the term. ? LokiClock (talk) 05:56, 7 July 2014 (UTC)

CS crank

Just wanted to draw attention to this user, who has recently created two very cranky looking articles (with main citations in MDPI, a predatory low-value journal) and started adding links to them from articles on CS and fractals. --JBL (talk) 13:19, 7 July 2014 (UTC)

Now at Wikipedia:Articles for deletion/AjoChhand Machine. --David Eppstein (talk) 21:20, 7 July 2014 (UTC)

...and Wikipedia:Articles for deletion/Frequency fractal. --David Eppstein (talk) 02:21, 8 July 2014 (UTC)

Jacob Barnett is up for deletion

Please comment at Wikipedia:Articles for deletion/Jacob Barnett (2nd nomination). S?awomir Bia?y (talk) 12:15, 25 June 2014 (UTC)

For those following the story, an admin decided to keep. The decision has since been appealed. I will never be able to figure out why people think that content like this is worth having in WP. Rschwieb (talk) 13:28, 9 July 2014 (UTC)

AfC submission - 11/07

Draft:1/ ?. FoCuSandLeArN (talk) 14:55, 11 July 2014 (UTC)

Classical group

I have rewritten the article completely. As it was before, it managed to miss the majority of the classical groups, but instead had bits and pieces on groups of Lie type that apparently fancied the authors more than classical Lie groups. I have retained most of that stuff, Classical groups over general fields or algebras, but I think it should go somewhere else. Suggestions? I opened a thread at the article talk page. YohanN7 (talk) 18:30, 11 July 2014 (UTC)

Talk:List of mathematical symbols reorg

I have proposed a reorganization of List of mathematical symbols at Talk:List of mathematical symbols#Reorganize. As it is a major change, I'd like some consensus and, if possible some help, before proceeding.--agr (talk) 15:26, 14 July 2014 (UTC)

Do we have these articles?

Do we have Lie correspondence and Closed subgroup theorem under different names? If not, I might write stubs for them. YohanN7 (talk) 20:20, 14 July 2014 (UTC)

There is Representation_theory_of_the_Lorentz_group#The_Lie_correspondence and Cartan's theorem. I found both of those articles using Wikipedia's search box. RockMagnetist (talk) 20:56, 14 July 2014 (UTC)

Lie algebra#Abelian, nilpotent, and solvable mentions the Lie correspondence for nilpotent and solvable cases but doesn't expound upon it. There are existing red links in various articles for Lie correspondence; I say go for the stub. "Closed subgroup theorem" is in a list of todos at Talk:List of theorems#TODO, so seems like a reasonable candidate for an article as well. --Mark viking (talk) 21:11, 14 July 2014 (UTC)

Thanks for the info. I'll definitely do the closed subgroup theorem because it seems manageable enough. The Lie correspondence is quite an undertaking, and I'll let that be for a little while to come. It really surprises me that there is no such article because the Lie correspondence is truly the fundamental result (or rather class of results) of Lie group theory. YohanN7 (talk) 22:46, 14 July 2014 (UTC)

As a placeholder, I have created Lie correspondence as a redirect. RockMagnetist (talk) 23:28, 14 July 2014 (UTC)

I don't think it's a good redirect. I simply started the Lie group-Lie algebra correspondence, though it's far from complete. -- Taku (talk) 01:00, 15 July 2014 (UTC)

While writing the draft for Closed subgroup theorem (not submitted yet, you are welcome to comment on its talk page), I bumped into the following missing articles candidates; Left invariant (often mentioned in Wikipedia), Group topology (strangely enough not mentioned anywhere, is it unusual terminology?) and Exponential coordinates (coordinates associated with the group topology, rarely mentioned in Wikipedia). YohanN7 (talk) 21:11, 15 July 2014 (UTC)

We have Exponential map and Topological group. We have Invariant, perhaps a a defn of left and right invariants could go there? Exponential map mentions, but does not define, left and right invariants of various objects. --Mark viking (talk) 23:34, 15 July 2014 (UTC)

It requires some thought. Left invariant vector fields constitute the Lie algebra of a Lie group, so that should probably go into one of the major articles (Lie group?). I think exponential coordinates and group topology perhaps could go in there as well, since they are natural constructs for a Lie group. YohanN7 (talk) 23:50, 15 July 2014 (UTC)

Draft now submitted: Closed subgroup theorem. I want it to go the official way to get some sort of sanity check. YohanN7 (talk) 23:50, 15 July 2014 (UTC)

Wow, nice work on short notice. It looks ready for mainspace to me. --Mark viking (talk) 00:16, 16 July 2014 (UTC)

Ty, blushing. You have probably not yet spotted all errors bound to be there. YohanN7 (talk) 00:22, 16 July 2014 (UTC)

Shouldn't it be called Cartan's theorem? (there is no question the theorem deserves an article on it.) -- Taku (talk) 01:41, 16 July 2014 (UTC)

How funny. It looks in Cartan's theorem like that the Lie correspondence is Cartan's theorem too, at least in its global form.

I can live with naming the article I wrote either "Closed subgroup theorem" or "Cartan's theorem", either way is fine. But I really think Lie group-Lie algebra correspondence should be renamed to "Lie correspondence". It sounds better and seems to be a little more common, including in Wikipedia. YohanN7 (talk) 02:14, 16 July 2014 (UTC)

About that. "Lie correspondence" didn't seem descriptive enough for me. Considering Wikipedia is a general encyclopedia, when there is no official or standard term, it's better to use a descriptive name. This is for example why Wikipedia includes the year in the name of an event article: e.g., 2014 Northern Iraq offensive, even the term is not commonly used in media. Also, "Lie correspondence" is a little ambiguous; there is Algebraic group-Lie algebra correspondence too. -- Taku (talk) 11:31, 16 July 2014 (UTC)

In that case, "Cartan's theorem" is decidedly inappropriate for the "Closed subgroup theorem", much more so than "Lie correspondence" for "Lie group-Lie algebra correspondence", which is actually used in the literature. "Lie correspondence" can hardly be confused with "Algebraic group-Lie algebra correspondence". YohanN7 (talk) 14:42, 16 July 2014 (UTC)

I don't think so since Cartan's theorem, in my impression, is fairly standard usage, while the term "Lie correspondence" doesn't appear in any of sources that are used in Lie group-Lie algebra correspondence. Of course, the perception depends on references one uses. But let me try this way too: "Lie correspondence" isn't precise enough; why "Lie" here has to refer to Lie groups? Why not Lie algebra? Why not Lie groupoid? The term would work perfectly in the books with the titles containing "Lie groups" but not quite in the places like here. The same problem with "closed subgroup theorem". Without context, it's not clear it's a result in Lie theory, while "Cartan" conjures the feel of Lie :) -- Taku (talk) 16:02, 16 July 2014 (UTC)

I have exactly the opposite impression from the literature. I have never seen "Cartan's theorem" (much more ambiguous than "Lie correspondence" according to Cartan's theorem (one form of it actually refers to a form of the Lie correspondence)) in the literature, but have always seen "Lie correspondence". But let us not argue about this. The descriptive names (as they are now) are, in view of this discussion, clearly better in both cases. YohanN7 (talk) 16:46, 16 July 2014 (UTC)

Affine space, forgot the origin: gibberish or functor?

Talk:Affine space#"Forgotten which point is the origin": gibberish or functor? Please look. Recent edits are generally constructive, but made by a person closer to physics than math (I feel so), with somewhat different philosophy. As for me, the views of physicists are welcome, but our views should not be exterminated. Boris Tsirelson (talk) 10:46, 8 July 2014 (UTC)

Just a small comment: it's not a good practice to confuse the zero vector with the origin, or is it? A polynomial ring (over a field) is a vector space but you don't really call the zero polynomial the origin. The term "origin" suggests positional concepts; i.e., a choice of basis/coordinates. The definition of "affine space" that I like is that it is an element if a quotient space V/W. The problem with this definition is that it is not intrinsic, but works perfectly otherwise. -- Taku (talk) 12:52, 8 July 2014 (UTC)

Tastes differ. In the theory of Banach spaces it is very usual to call 0 the origin. If I think of the vector space of polynomials geometrically, then indeed I think of 0 as the origin, of constant polynomials as a straight line through the origin, and so on. But maybe this is typical for a relatively small group of mathematicians? I do not know. Boris Tsirelson (talk) 13:42, 8 July 2014 (UTC)

Presumably in an encyclopedic article it would be good to have at least a brief discussion of all these different perspectives. --JBL (talk) 15:03, 8 July 2014 (UTC)

This seems very standard as an intuitive description of an affine space. The zero in a vector space is often called an origin, especially when concerned with the geometry of affine spaces. The article includes a quotation by Marcel Berger including the term "origin" in this context. It should be allowed to stay as it is. S?awomir Bia?y (talk) 15:36, 8 July 2014 (UTC)

Gibberish, but good gibberish. Let in. YohanN7 (talk) 16:23, 8 July 2014 (UTC)

May I say that I have a first in mathematics from Cambridge University, and a Ph.D. in mathematics from University of London, so I think I am by training closer to mathematics than to physics. As has previously been remarked by other, the mathematical definition of vector space, which does not mention an origin. It has an identity element, which certainly cannot be forgotten, and which cannot be identified with an origin. It is not appropriate for mathematical articles to be written by people abusing mathematical words. RQG (talk) 17:39, 8 July 2014 (UTC)

"[A vector space] has an identity element ... which cannot be identified with an origin." This statement is just false, both as a statement about formalisms and as a statement about common usage by [many] mathematicians. --JBL (talk) 17:52, 8 July 2014 (UTC)

Abuse of language has a long and distinguished tradition in mathematical discourse, being frequently employed even by such luminaries of the formalist perspective as Nicolas Bourbaki. The section that you continue to try to delete, without consensus, is clearly not meant to be a formal description anyway (even the title of the section is "Informal descriptions".). Regarding the use of the word "forget", the assignment of the affine space underlying a vector space is indeed an example of a forgetful functor. If one regards vector spaces geometrically, rather than algebraically, it is precisely the functor that "forgets" the origin. This perspective is well-supported by high quality references (and standard use in the mathematical community). S?awomir Bia?y (talk) 18:41, 8 July 2014 (UTC)

RQG has a point, although he presents it in a way which is not entirely helpful (appeals to personal authority tend not to go down well). The question is about language and the abuse thereof, creative an otherwise. One could unpick the various concepts as follows. A vector space over a field is an algebraic object with algebraic axioms. Being a group it has a zero element. A linear space (a term which is not much in use, and here redirects to vector space) is a geometric object satisfying certain geometric axioms. As a geometric object it has a special point called O or the origin. The axioms of a vector space are sufficiently abstract that the concept is capable of modelling a linear space. An affine space (1) is an algebraic object which is a principal homogeneous space over a vector space, or a commutative heap on which a field acts. An affine space (2) is a geometric object which satisfies axioms (about parallel lines and parallelograms). An affine space (2) can be modelled by an affine space (1), the para-associative law is the existence of parallelograms. A linear space is an affine space (2) with a distinguished point called the origin. A vector space is an affine space (1) with a distinguished element called zero. The questions are, how to present this on Wikipedia, and in particular whether the slogan in question is helpful or unhelpful for the reader who wants to understand and remember the material. Obvious but important mistake corrected. Deltahedron (talk) 17:25, 16 July 2014 (UTC)

Is not the idea of a principal homogeneous space as a space with a free and transitive group action already a geometrical one? One often describes a principal homogeneous space as a group without a fixed identity element. That is a group in which we forget the identity. So I don't think the distinction you're making reflects actual usage. S?awomir Bia?y (talk) 17:58, 16 July 2014 (UTC)

I'm trying to unpack the various possible meanings using an ad hoc terminology to make the discussion easier -- I'm not claiming these are universally accepted terms or that Wikipedia should use them: I'm asking how they should be presented. Deltahedron (talk) 18:44, 16 July 2014 (UTC)

One more source of ideas: nLab:affine space. Boris Tsirelson (talk) 19:12, 16 July 2014 (UTC)

I think this seems like a much more productive direction than continued quibbling over the informal description. There is good stuff in that article. S?awomir Bia?y (talk) 19:38, 16 July 2014 (UTC)

The nature of the misunderstanding?

Quote from "RQG":

"Take an affine space (A,V). Choose a point a as origin. Then you have a particular representation of A, together with a vector space V. You do not have V=(A,V), which is what you are saying, and which is patent nonsense. To get the vector space from an affine space you have to forget A, not choose an origin. The origin is a point in A. It is not in V."

End of quote from RQG

This says "Take an affine space (A,V)". I take that to mean A is a set and V is a vector space that acts transitively on that set in a way that satisfies certain desiderata. RQG seems to say that if you then delete A from this structure, you're left with V, so that an affine space is something more than a vector space: If you start with an affine space and discard part of the structure, you're left with a vector space. That is consistent with at least this much of the way I originally learned it: An affine space has an underlying set A and some vector space that acts on A in a certain way. But this notion that an affine space is (A,V) where A and V satisfy certain conditions and are related in certain ways is only one way of encoding the concept of affine space. There are others. One of those other goes like this:

A vector space involves an underlying set V whose members are called vectors, and a field F whose members are called scalars, and an operation of linear combination by which one takes scalars s₁,...,s_n and vectors v₁,...,v_n, one gets a vector s₁v₁ + ... + s_nv_n, and this operation of linear combination satisfies certain algebraic laws.
An affine space involves an underlying set A whose members let us call "points", and and a field F whose members are called scalars, and an operation of affine combination by which one takes scalars s₁,...,s_n satisfying s₁ + ... + s_n = 1, and points p₁,...,p_n, and gets a point s₁p₁ + ... + s_np_n, and this operation of affine combination satisfies certain algebraic laws.

This is demonstrably equivalent to the "(A,V)" characterization of affine spaces. I leave the proof of equivalence to RQG as an exercise. And any undergraduate reading this may also find it useful to go through this exercise. By this second characterization of the concept of affine space, a vector space is an affine space with this bit of additional structure: One chooses some point which we will call 0 to serve as the origin or zero or whatever you want to call it, and and then one can define a linear combination s₁p₁ + ... + s_np_n in which s₁ + ... + s_n need not add up to 1 by saying that it is

s₁p₁ + ... + s_np_n + (1 - s₁ - ... - s_n)0.

Viewed in that way, a vector space is an affine space with some additional structure. And this way of viewing it is demonstrably equivalent to the "(A,V)" point of view.

I am pleased to see that user:John Baez has joined the discussion on the article's talk page. Michael Hardy (talk) 03:54, 17 July 2014 (UTC)

Yes. But, ridiculously, RQG thanks John for clarifying "that an affine space has more structure than a vector space"! I guess, the problem is, not understanding the difference between "principal base sets" and "auxiliary base sets" (in the Bourbaki terminology). For a vector space over a field, the field is auxiliary, not principal. Accordingly, no one introduces "the forgetful functor from the category of vector spaces to the category of fields". Likewise, for an affine space, its difference space is auxiliary, not principal. Indeed, "a continuously differentiable map from one finite-dimensional affine space to another" means a map from A₁ to A₂ (surely not from V₁ to V₂). Accordingly, I think, "the forgetful functor from the category of affine spaces to the category of vector spaces" is not a good idea. Boris Tsirelson (talk) 05:50, 17 July 2014 (UTC)

Another similar case (for example). A topological space is usually defined as a pair (set,topology), the topology being the set of "open" subsets. The topology is in fact a partially ordered set (by inclusion), moreover, a lattice. It is legitimate to consider the functor (set,topology)->topology, from the category of topological spaces to the category of lattices. However, would anyone call this functor "forgetful"? Definitely, I would not.

Such functors may superficially seem to be forgetful in one definition (of the "from" category), but do not sustain transition to an equivalent definition. A topological space may be defined, equivalently, via neighborhoods. An affine space may be defined equivalently... see above... not mentioning a vector space. The functors are still well-defined, but do not seem to be "forgetful" anymore. Since really they are not.

The true meaning of a mathematical notion, on one hand, and its specific encoding (via sets), on the other hand, should not be confused. An equivalent definition leads to the same notion, but (often) another encoding. Boris Tsirelson (talk) 08:02, 17 July 2014 (UTC)

Isn't "The location of the gap in somebody's understanding?" quite a nasty subject title? There may be holes in your brain too. YohanN7 (talk) 15:50, 17 July 2014 (UTC)

I felt so too, and have retitled. --JBL (talk) 16:28, 17 July 2014 (UTC)

Problems at that article appear to continue. I begin to suspect definite WP:COMPETENCE issues after RQG's insistent misunderstanding of Baez's post on the matter. S?awomir Bia?y (talk) 18:21, 17 July 2014 (UTC)

Double factorial vs semifactorial

Zaslav (talk · contribs) has moved double factorial to semifactorial, claiming that this name is both more traditional and more correct, and has edited many other articles to implement the same change. Some of us disagree. Please join the discussion at Talk:whichever name it is. --David Eppstein (talk) 04:40, 17 July 2014 (UTC)

Wow. I'm all for WP:BOLD but this seems like it was a bad move. --Kinu ^t/_c 04:50, 17 July 2014 (UTC)

Excellent idea, David Eppstein. I'm afraid I jumped into a confused area of terminology. For instance, the "double factorial" article gave three definitions of an even "double factorial", one of which is "semifactorial", another of which is called "odd factorial", and the third of which, in terms of gamma functions, is different from both. I am now thinking there should be separate articles. For instance, the "semifactorial" n(n-2)... is used in combinatorics, while the gamma-function-defined "double factorial" is not. On the other hand, it's possible the "double factorial" mentioned in some of the analytical articles is not the semifactorial (but it is, in articles on volumes of spheres). I am abandoning the edit of Semifactorial, formerly Double factorial, until this is cleared up. I can't clear it all up myself.

Note 1: I made a bad mistake by assuming this was a simple matter. I acknowledge it was my bad.

Note 2: Possibly Meserve was the first to use the !! notation but the semifactorial was certainly known long before that. What it was called, if anything, is not known to me. My teachers in the 1960s said the name was "semifactorial" (and I believed them implicitly), so I'm sure there is something more to the history than the article says.

Note 3: There should be a distinction between notation and concept. The function "semifactorial" ("double factorial" in the parity product meaning) is not the same as the "double factorial" notation. Is the article to be about the function(s) or the notation? (Is the answer obvious?!) Zaslav (talk) 04:57, 17 July 2014 (UTC)

I know we cannot depend on Google searches, but Google finds no references to "semifactorial" outside of Wikipedia. "Semi-factorial" and "Semi factorial" are sometimes used. I think this needs to be reverted. Now. If Zaslav isn't willing to do it, then he needs to stop editing until this can be resolved. "Google scholar" searches are even more impressive (238 v 1880), but few of either of them are this topic. -- Arthur Rubin (talk) 06:11, 17 July 2014 (UTC)

The Estonian and Farsi Wikipedias use "double", while Swedish uses "semi". The more I look, the more confused I get. -- Arthur Rubin (talk) 07:49, 17 July 2014 (UTC)

Thank you, Arthur Rubin, for your help. All in all, I made a stupid mistake. I will check to see if there are any further reverts needed.

There is still the issue of the three contradictory definitions of "double factorial" as well as the ambiguously related term "odd factorial". According to the WP article, the use of n!! for even natural numbers n is not well defined. There needs to be some work on that. Some of my edits were to put the "correct" definition in some articles. That still should be done. Zaslav (talk) 15:14, 17 July 2014 (UTC)

I see there are (possibly more than 2) definitions of double factorial/semifactorial, all of which coincide if the argument is an odd integer (positive or negative), and differ if the argument is a nonnegative even integer. As we (Wikipedia) seem to use it only for integer arguments, it may make a difference. -- Arthur Rubin (talk) 18:27, 17 July 2014 (UTC)

"Semifactorial" would be unambiguous. It "clearly" means alternating factors and nonfactors down to 1. (Cf. Michael Hardy's following comment.) "Odd factorial" would also be unambiguous; it "clearly" means only odd factors down to 1. (I personally never heard of it and have never seen any use of it.) "Double factorial" is the problem. This should be continued on the Talk:Double factorial page. Zaslav (talk) 16:40, 18 July 2014 (UTC)

"Semifactorial" seems like a good name for the concept, because you're only multiplying half the integers. I don't recall having heard it before. I've always thought the notation n!! is obnoxious because it looks like the factorial of the factorial, and that is not at all what is meant. Michael Hardy (talk) 23:54, 17 July 2014 (UTC)

I agree it seems a good name. I've just never seen it used, and we need a related name for multifactorial Semifactorial as an instance of multifactorial sounds particularly weird. -- Arthur Rubin (talk) 15:38, 18 July 2014 (UTC)

I agree with both of you (thanks, Michael Hardy). I will still favor "semifactorial" in my own writing. However, as an encyclopedia, WP ought to follow convention. I'm now convinced that "double factorial" is overwhelmingly the most used. And thanks again to Arthur Rubin for reverting for me. Zaslav (talk) 16:36, 18 July 2014 (UTC)

signal-flow graph could use a bit more math

It's actually written in a rather impenetrable engineering jargon/style as far as I'm concerned. It's basically just a bunch of examples, and it's kinda missing all its math content/background, which is a bit non-trivial. A search found that the recommend text (up to 1980s or so) for the mathy part is Wai-Kai Chen (1971). Applied Graph Theory. Elsevier. ISBN 978-0-444-60193-3. . Chapters 3-4 in particular, but most of the book is basically just about this topic. There actually two signal-flow graphs, the Mason graph and the Coates graph and they can be converted to each other easily, but no such info can be gleaned from wikipeidia etc. 188.27.81.64 (talk) 04:45, 21 July 2014 (UTC)

Graph categories: some clean-up might be needed

There seem to be 3 categories that more or less overlap in their actual contents:

Category:Graph theory objects
Category:Application-specific graphs
Category:Graph data structures

I'm guessing the first one is intended for "core" graph theory concepts. But some concepts like interval (graph theory) are application specific, but aren't exactly graphs themselves so don't neatly fit in the 2nd category. The third category seems to be the most problematic, as it seems to contain mostly items that should be in the 2nd one (app-specific graphs) or some variation thereof, i.e. are graphs augmented with various other info. Most of the stuff in the 3rd category aren't actually ways to implement graphs as data structures, e.g. adjacency list seem okay in that category, but and-inverter graph seems to belong to 2 instead--the article doesn't even say how these might be implemented. 188.27.81.64 (talk) 13:14, 21 July 2014 (UTC)

Many of the things in the 3rd list are data structure that take the form of graphs. I agree that they should be separate from data structures for representing graphs. The category for data structure in the form of graphs should probably be a subcategory of application-specific graphs. --David Eppstein (talk) 16:12, 21 July 2014 (UTC)

That sound good to me. Still, the smaller problem of categorizing app/domain specific concepts (rather than whole graphs) remains. They seem to be all over the place. E.g. dominator (graph theory) is in the main category (Category:Graph theory) whereas interval (graph theory) is in category #1 ("objects") from the above list. 188.27.81.64 (talk) 19:09, 22 July 2014 (UTC)

Some of that is just articles not yet having been sorted into appropriate subcategories of the main graph theory category. If you think they should be in a specific subcategory (as seems likely in this case) please go ahead and make that change. --David Eppstein (talk) 21:03, 22 July 2014 (UTC)

Equivalent definitions of mathematical structures

Bothered with the recent trouble with affine spaces, I'd like to have an article about "Equivalent definitions of mathematical structures". To this end I ask myself two questions:

(a) What can we reasonably say in this direction?

(b) Which part of the said can we find in reliable sources?

Item (a).

First, some case study.

Topological space has at least 7 definitions. "The utility of the notion of a topology is shown by the fact that there are several equivalent definitions of this structure. Thus one chooses the axiomatisation suited for the application." (From "Topological space".)

Uniform space has at least 3 definitions.

Differentiable manifold has at least 4 definitions.

Algebraic space has at least 2 definitions.

Ordered field has at least 2 definitions.

Surely, in each case these definitions are equivalent. But what exactly does it mean? From the article "Topological space": "there are many other equivalent ways to define a topological space: in other words, the concepts of neighbourhood or of open respectively closed set can be reconstructed from other starting points and satisfy the correct axioms". But it refers to the main article "Characterizations of the category of topological spaces"; there the equivalence means isomorphism of categories. This does not make me happy. First, having the category of topological spaces up to isomorphism I still do not know what is a topology on a given set. Second, yes, continuous maps are most natural as morphisms, but other possibilities exist (and are sometimes used), such as open maps or even Borel measurable maps.

According to the article Ordered field the equivalence means that "there is a bijection between the field orderings of F and the positive cones of F". I dislike this formulation. As for me, "there is" means "exists", and "exists a bijection" means, equal cardinalities. No, surely this is not meant! Rather, it is meant that the specific correspondence described there in the next lines is a bijection.

Now, some thoughts.

If I ask you "give me an example of a topology on the 2-element set {a,b}", you may give me the set "{{},{a},{a,b}}" of all open sets, or the function "a->{{a},{a,b}},b->{{a,b}}" that maps each point to the set of all its open neighborhoods, and so on. I'd say, this is similar to describing a vector in this or that coordinate system. But for a vector, our level is much higher! We have the general notion of a coordinate system, a general transformation formula for vector coordinates, and (if we are physicists) we can define a vector as something that transforms this way. For topologies, even this "physical" level is still in the sky! Do we imagine the class of all (rather than these 7) equivalent definitions of a topology? Can we define a topology as something that transforms as required from one definition to another? (Yes, we can do so for the 7 definitions, but I really mean all potentially possible definitions.)

Given a cardinality ?, introduce the category S(?) of all sets of this cardinality, with bijections (not all maps!) as morphisms. Each definition of topology leads to a functor S(?)->S(?), (a set)->(the set of all topologies on this set). Two equivalent definitions lead to two naturally equivalent (in other words, naturally isomorphic) functors. It is tempting to consider the whole equivalence class of functors (similarly to the class of all coordinate systems). Pretty elegant, and general (applies to all structures, not just topologies). However, there is a problem.

Is it true that for every pair of naturally equivalent functors (of this kind) there exists only one natural equivalence between them?

Even simpler: what if there exists a nontrivial natural equivalence from one such functor to itself?

For topologies in general, I do not know. (Do you?) But for some mathematical structures the answer is discouraging: yes, there exists a nontrivial natural equivalence from one such functor to itself. For groups, it happens because of opposite group. For topologies on two-element sets, it happens because of possible swapping of "{{},{a},{a,b}}" and "{{},{b},{a,b}}" (exercise: check that continuous maps are insensitive to this swap).

Thus, it seems, we are able to list a finite number of definitions (for a given mathematical structure) and write down a consistent (that is, commutative) system of natural equivalences between them. But we are unable to do more.

Do you agree? Boris Tsirelson (talk) 18:29, 20 July 2014 (UTC)

There is something like this already at cryptomorphism. The article is very specific to matroid theory, though, and I don't know if that specific word has been used in a lot of other contexts. --David Eppstein (talk) 18:51, 20 July 2014 (UTC)

The question about nontrivial natural equivalences reminds me of ?-categories. I believe that the disciples of homotopy type theory would tell you that if two definitions give you equivalent ?-categories, then the two definitions are indistinguishable, and therefore you shouldn't worry about the difference. I think, however, that that will not satisfy you. Your question seems to ask for a Bourbaki-style answer in terms of sets with additional structure.

Personally, I have long thought that for formal purposes, one should treat different definitions as defining different kinds of structure (whether you're working in terms of structured sets, categories, ?-categories or whatever) and then prove that those structures are equivalent or isomorphic as appropriate. (For example, the category "topological spaces in terms of open sets" is isomorphic (not merely equivalent) to the category "topological spaces in terms of closed sets".) So long as you are clear on exactly what kinds of properties you are hoping the definitions to express, this has always seemed sufficient to me. Ozob (talk) 21:06, 20 July 2014 (UTC)

I think that seeing the equivalence between defining topological spaces in terms of open sets or in terms of closed sets as categorical is somewhat weaker than what's going on the the mind of the mathematician: they are attempts to define the "same thing". Deltahedron (talk) 21:41, 20 July 2014 (UTC)

But I like categories. Ozob (talk) 03:24, 21 July 2014 (UTC)

Categories are very interesting, and I use this occasion for learning more on them. However, I could not like such a definition of topology that cannot answer questions like "is this set open in this topology?" I want to use the Baire category theorem (when applicable). I want to consider probability measures in topological spaces, and see that (under appropriate conditions on the topology) each measure sits on some sigma-compact set. Etc, etc. Can I do it in the category language? Boris Tsirelson (talk) 05:35, 21 July 2014 (UTC)

You might want to follow the example I set in finite set#Necessary and sufficient conditions for finiteness. One definition is taken as the official definition and the equivalent definitions are rolled into a theorem stating that they are all the same thing. JRSpriggs (talk) 07:07, 21 July 2014 (UTC)

This is exactly what I'd like to avoid. In the vector metaphor, it means: "officially" define a finite-dimensional vector space as Rⁿ, and then discuss arbitrary coordinate systems in addition to the "official" one. Boris Tsirelson (talk) 07:31, 21 July 2014 (UTC)

I think it's helpful here to distinguish the defining properties of a mathematical object (e.g. a vector space is a group with a scalar multiplication operation over a field (etc), its dimension if finite is the maximum number of independent vectors, etc) from the models of those objects (Rⁿ). (Coming from a CS point of view, I think of these as analogous to abstract data types vs their implementations.) I wouldn't use Rⁿ as the definition of a finite dimensional vector space; it (together with the right tuple of operations) is an example of a finite dimensional vector space. (For instance, I think of k-tuples of members of GF(2), with pointwise addition, as having a different data type than subsets of the numbers 0, 1, ..., k - 1, with symmetric difference of sets, and that in turn is different from k-bit binary numbers, with bitwise exclusive or, but all three give naturally-isomorphic finite dimensional vector spaces.) You could define a finite dimensional real vector space as being a vector space isomorphic to Rⁿ, but you'd need to have already defined vector spaces and isomorphisms already for that to even make sense, and it would be an ugly definition to choose as the primary one. --David Eppstein (talk) 07:44, 21 July 2014 (UTC)

Sure. But here I do not really discuss definitions of a vector space. Rather I use this as a metaphor; see my first message, the paragraph "Now, some thoughts". And I would be happy to treat topologies as an abstract data type, and the 7 definitions as 7 implementations (equally "official", or equally "unofficial"). Can I? Boris Tsirelson (talk) 08:28, 21 July 2014 (UTC)

Really, now I feel that the "abstract data type" (thanks to David) is the most apt word.

After more thinking I see how naive is my original idea that functoriality itself can dictate a single bijection between, say, topologies as sets of open sets, and topologies as families of neighborhood filters. (Initially I wrote I do not know whether this fails... now I see it surely fails.)

A notion of a mathematical structure arises from our intuition; and these bijections between different "implementations" are dictated by our intuition (rather than a formal requirement). Therefore the number of "implementations" must be finite (since our intuition cannot do more) (but of course some parameters running over infinite sets could appear).

Now the question is, to which extent is it (not) Original Research? Boris Tsirelson (talk) 08:58, 21 July 2014 (UTC)

Something that would be indirectly relevant: "From Set Theory to Type Theory" by Mike Shulman; "Why do categorical foundationalists want to escape set theory?" (Mathoverflow); Homotopy type theory; Sear (redlink to "SEAR (mathematics)"); Univalence axiom. Boris Tsirelson (talk) 13:22, 24 July 2014 (UTC)

'Mathematicians are of course used to identifying isomorphic structures in practice, but they generally do so by "abuse of notation", or some other informal device, knowing that the objects involved are not "really" identical. But in this new foundational scheme, such structures can be formally identified...' (Subsection "Univalent foundations" of Introduction in book:Homotopy Type Theory: Univalent Foundations of Mathematics. The Univalent Foundations Program. Institute for Advanced Study). Boris Tsirelson (talk) 16:59, 24 July 2014 (UTC)

I agree that type theory presents an intriguing alternative to set theory and category theory as a foundational system. In Shulman's piece, there was a good discussion of equality and isomorphism. Getting back to your original proposal, perhaps the isomorphism article would be a good location to expand upon equivalent definitions of mathematical structures. While there are surely foundational and metamathematical sources that discuss structural equivalence in these broad terms, the idea of isomorphism occurs in all three systems of set, category and type theory and could be a good launching point for readers. There is already some material on the notions of isomorphism and equality there. --Mark viking (talk) 18:19, 24 July 2014 (UTC)

Maybe. But, as noted by David (above), it is rather a cryptomorphism. Indeed, it is unusual to consider isomorphisms between different (differently described) structures. Moreover, in order to introduce such notion, a specific transition between such structures must be chosen. Boris Tsirelson (talk) 19:25, 24 July 2014 (UTC)

Well, I did: Equivalent definitions of mathematical structures; please look. Improvements are welcome, of course. Boris Tsirelson (talk) 19:14, 28 July 2014 (UTC)

Wikipedia talk:Articles for creation/Chi-squared divergence

Dear mathematicians: Some time ago I asked about this draft article, but received no reply. I am assuming that it is not a notable topic and should be deleted. --Anne Delong (talk) 19:24, 27 July 2014 (UTC)

Maybe not. Google gives me 5270 results to "Chi-squared divergence" (with the quotation marks). Surely, the author did very little. I am not enthusiastic to collaborate in that. But the topic could have some notability. Boris Tsirelson (talk) 20:14, 27 July 2014 (UTC)

"Chi-squared divergence" gets 58 hits in GScholar, not a lot, and none of the most cited papers are about this divergence in particular. It is a minor variant in a family of distribution metrics and divergences. I think notability is marginal and may not survive an AfD. The divergence is verifiable, however, and a redirect to f-divergence#Instances of f-divergences, where it is mentioned, seems warranted if this is not kept. --Mark viking (talk) 20:49, 27 July 2014 (UTC)

Ah, yes, a good redirect. Boris Tsirelson (talk) 21:10, 27 July 2014 (UTC)

It's a redirect at Chi-squared divergence now, but the text is available in the history if anyone wants to add some of it to the main article. --Anne Delong (talk) 01:55, 30 July 2014 (UTC)

"Constant curvature" needs some tender loving care

The article Constant curvature appears to be in a rather poor state for an old and important article. I only noticed it because someone changed a link at Hyperbolic space to point to it. JRSpriggs (talk) 02:37, 30 July 2014 (UTC)

Soon-to-be-deleted article

For some amusement, before it's gone, check out Is theta a scalar quantity or vector quantity. --David Eppstein (talk) 07:02, 23 July 2014 (UTC)

Well, at least that one didn't last 8 years. 188.27.81.64 (talk) 10:01, 23 July 2014 (UTC)

Well, it actually might last 8 more years. Someone "saved" it by pasting a bunch of references to papers about graphs being used for something else, papers that happen to have a guy named Muller among the authors. JMP EAX (talk) 19:25, 25 July 2014 (UTC)

Before reading that, I had not suspected that no scalars are negative. Michael Hardy (talk) 19:12, 25 July 2014 (UTC)

Grafting (ordered tree) is another pearl. Lesson learned: I'm not mentioning it on Jimbo's page. This article is already in "saved" format, meaning it consists of a bunch of non-sequiturs with some ref tags. JMP EAX (talk) 19:25, 25 July 2014 (UTC)

(ec) Current convention is not to delete articles if the underlying topic is notable. Is there a single thing that is represented by "Grafting (ordered tree)" that could be used to cut an unsatisfactory article back to a stub and then grown out again? Deltahedron (talk) 19:31, 25 July 2014 (UTC)

In the time it took you write that you could have done the trivial work of clicking the article's history and see for yourself that the answer is no. If you really think that the editor who made this edit could possibly write something intelligent in a math/CS article, then you probably drank too much wikicoolaid about the encyclopedia that anyone can (but should?) edit and so forth. JMP EAX (talk) 20:23, 25 July 2014 (UTC)

It is more helpful to comment on the content, not on the contributor. If there is no prospect of writing even a short stub, then that is an argument for deletion. Deltahedron (talk) 20:46, 25 July 2014 (UTC)

Oh, and rooted binary tree is actually citing its source correctly, except the source doesn't make (much) sense. JMP EAX (talk) 19:27, 25 July 2014 (UTC)

Well, someone figured that one out. Vertices ? nodes for some. JMP EAX (talk) 19:29, 25 July 2014 (UTC)

Insert obligatory quote from Knuth here: "The material that follows comes mostly from a larger area of mathematics known as the theory of graphs. Unfortunately, there will probably never be a standard terminology in this field, and so the author has followed the usual practice of contemporary books on graph theory, namely to use words that are similar but not identical to the terms used in any other books on graph theory." JMP EAX (talk) 19:33, 25 July 2014 (UTC)

Rooted binary tree is clearly a notable concept. reliable sources would be easy to find. Deltahedron (talk) 19:36, 25 July 2014 (UTC)

And different from binary tree how? JMP EAX (talk) 20:24, 25 July 2014 (UTC)

In being rooted, I would imagine. Propose a merge and redirect if you think the difference is insufficient. Deltahedron (talk) 20:29, 25 July 2014 (UTC)

May I suggest to you to spend the next 500 years of your life saving this edit? JMP EAX (talk) 20:35, 25 July 2014 (UTC)

Why? Do you think it's important? Deltahedron (talk) 20:42, 25 July 2014 (UTC)

Your sarcasm is unwarranted. Deltahedron is a well-known contributor here, and his comments are calm and in line with Wikipedia policy. We all share your frustration with material that shouldn't be on Wikipedia but is. Ozob (talk) 23:44, 25 July 2014 (UTC)

Thanks for that. As far as unwanted content is concerned, I simply want us to distinguish between useful/useless topics for articles and useful/useless article content. Deltahedron (talk) 08:30, 26 July 2014 (UTC)

What can I say. Do I see double today [24]? Same content, "different" user. Allow me to be frustrated just a little bit. 188.27.81.64 (talk) 14:39, 26 July 2014 (UTC)

Just to spell this out for the benefit of passing readers: the articles Grafting (algorithm) and Grafting (ordered tree) appear to be substantially identical, despite having been created by apparently different users, User:Mmmzeta0 and User:Exe89. The articles have been proposed for deletion by User:JMP EAX and 188.27.81.64 (talk · contribs · WHOIS). Deltahedron (talk) 16:33, 26 July 2014 (UTC)

+----------------------------------------------------------------------------------------------------+ n.b. I have amused myself by completely rewriting Grafting (algorithm). The article is no more and no less than Left-child right-sibling binary tree. A redirect there might be marginally helpful, but I'm not going to argue too strenuously for it. Lesser Cartographies (talk) 03:26, 30 July 2014 (UTC)

Aug 2014

Draft:Deformation tensor

Could someone take a look at this Draft to see if should be approved. I'm just not sure there is enough there for its own article or if it should be approved or something else...Naraht (talk) 02:07, 2 August 2014 (UTC)

René François Walter de Sluse

I believe those two are the same person, but my English is not good enough to start merging discussion:

René-François de Sluse
René François Walter de Sluse

- Vlsergey (talk) 10:56, 29 July 2014 (UTC)

Both articles are about René François Walter de Sluze. Merging should be uncontroversial. Deltahedron (talk) 06:51, 2 August 2014 (UTC)

McShane

Should we have an article titled McShane integral? Michael Hardy (talk) 17:43, 3 August 2014 (UTC)

(It appears that the McShane integral and the McShane-Whitney extension theorem are both named after the same person, but McShane's identity may be named after someone else. Michael Hardy (talk) 17:46, 3 August 2014 (UTC))

The first appears to be Edward James McShane [25], the second Gregory McShane [26]. Deltahedron (talk) 18:34, 3 August 2014 (UTC)

Richard Gosselin

I've proposed deletion for the article about mathematician Richard Gosselin after failing to find sources that could be used to verify the information in this (very short) article and demonstrate some notability for its subject. Perhaps someone else here can do better in this regard. --David Eppstein (talk) 22:54, 3 August 2014 (UTC)

Wikipedia:Articles for deletion/Ankur Tiwari

People may be interested in this 19-year-old Indian who has invented a way of dividing by zero, and developed a supercomputer which maintains "the complete 100% accuracy in all the mathematical operations." JohnCD (talk) 15:25, 4 August 2014 (UTC)

I was a bit interested, and have read his article about dividing by zero. Three ideas that I understood are:

let us waive continuity condition on the function 1/x, and then we can define it at 0 as we like, with no contradiction;
let us treat division as division with remainder, then we may treat 1/0 as 0 with remainder 1;
let us define 1/0 as the limit of ${\frac {1}{2}}({\frac {1}{-x}}+{\frac {1}{x}})$ as x tends to 0; then we get 1/0 = 0.

Wow indeed... :-)

Important copyright notice: I did not quote any line of his article (which is explicitly prohibited by him, "not even to personal blogs and sites"). Rather, I presented my impressions in my own words (and formulas). Thus, hopefully, I avoid legal actions promised by the author.

Boris Tsirelson (talk) 20:22, 4 August 2014 (UTC)

Alice has prior art [27]. Deltahedron (talk) 20:33, 4 August 2014 (UTC)

We could also define 1/0 as

i

. After all it is an imaginary amount. I'm sure that would be just as useful and consistent. ;-) By the way APL defined 0/0 to be 1 whereas the J programming language has it as zero - you can see their wonderful list of reasons at [28]. Dmcq (talk) 21:16, 4 August 2014 (UTC)

Even when programming in C++ you don't necessarily get that blue-screen these days that you so well deserve (for the sake of quality (and even safety) for the consumer of your software) when screwing badly. It is a while ago since I programmed now, but are floating-point exceptions and divide by zero exceptions even issued these days? My impression has been (in fairly recent years) that the underlying language and/or OS try to smooth over programming mistakes to give an impression of "stability". And oh, your "J-link" is marvelous reading. YohanN7 (talk) 21:54, 4 August 2014 (UTC)

See IEEE 754, particularly the "Exception handling" and "Recommendations" sections. No such user (talk) 08:22, 5 August 2014 (UTC)

Boris gave a pretty good summary. Also, according to that paper, the formula 1/0=0 leads to important applications in intellectual property. (I'm not kidding; this claim is actually in there!) S?awomir Bia?y (talk) 22:40, 4 August 2014 (UTC)

Tensor Flight Dynamics

Notable? The author of the article appears to have written most its references. Might be legit, have no idea, but the suspicion of self-promotion is automatically there when this happens. The article was also linked (by the author) from Tensor, but I just reverted that. YohanN7 (talk) 17:54, 4 August 2014 (UTC)

While we're cleaning out non-notable self-promotion, Laplacian of the indicator is also worth a look. (And this article is already a few years old, so there's less of a worry about possible biting of the newcomers.) S?awomir Bia?y (talk) 22:20, 4 August 2014 (UTC)

Nominated for deletion here. --Kinu ^t/_c 20:17, 7 August 2014 (UTC)

Avoid png rendering at all costs

It was pointed out at the talkpage of Lie group-Lie algebra correspondence that the png renderings of math formulae do not look good. My question is: do they really? I usually edit Wikipedia on my phone and on my screen the png rendering doesn't look bad. I'm wondering about what other people see. -- Taku (talk) 15:15, 20 July 2014 (UTC)

As a general rule, I prefer HTML for inline mathematics because this has the right size and alignment with the surrounding text, and latex for math appearing on its own line. Sometimes I have noticed also that the PNG images are of an insufficient resolution, rendering the resulting images indecipherable blurry. That having been said, the promise of functioning MathJax on the indefinite horizon will hopefully make such discussions fruitless. As for the article under discussion, most of the inline formulas there should be converted to HTML, the most glaring example being

\operatorname {Lie} (G)

. Also, I agree that for some reason inline latex seems to look better on an iphone. Perhaps a more responsive design would help to make things look better for all users. Then again I am too cynical to think this would do any good. S?awomir Bia?y (talk) 18:51, 20 July 2014 (UTC)

It just occurred to me that the computer should be able to convert latex to html, no? It requires the humans to do conversion seems [fill the blank]. -- Taku (talk) 16:52, 24 July 2014 (UTC)

The software used to be more aggressive about converting the <math> tag to HTML when possible, but now Template:math is preferred for explicit HTMLing with <math for explicit PNGing. I think it the template works better and gives more control. For example, the <math> tag never HTML'd subscripts, mathrm, spacing, or greek letters. But with {{math|}} , I can say 2x × ?y = cos(?_B) . SamuelRiv (talk) 01:10, 10 August 2014 (UTC)

Algorithm examples

See Talk:Algorithm examples for a discussion on the naming and use of this article -- 65.94.169.222 (talk) 05:18, 9 August 2014 (UTC)

Thus article is also discussed for deletion. See Wikipedia:Articles for deletion/Algorithm examples??. D.Lazard (talk) 19:16, 10 August 2014 (UTC)

Packing fraction

I have changed Packing fraction and Packing Fraction, which previously redirected to Atomic packing factor to redirect to Packing density, which I recently created. It is possible that a disambiguation page or other solution is needed, such as merging Packing density with Atomic packing fraction under the title Packing fraction. Judging from the incoming links to Packing fraction, they should all indeed point to Packing density as none discuss atoms. Eigenbra (talk) 05:05, 11 August 2014 (UTC)

Mathoid

Members here interested in mathematics rendering and editing may like to look at mw:Mathoid, a MediaWiki application which takes various forms of math input and converts it to MathML + SVG output. Deltahedron (talk) 08:27, 26 July 2014 (UTC)

See also this posting. Deltahedron (talk) 18:09, 11 August 2014 (UTC)

Kathleen Ollerenshaw?

A user is persistently adding a claim to this article that she has died. Can anyone verify that? I can't find anything online. Deltahedron (talk) 20:25, 11 August 2014 (UTC)

BBC Radio Manchester appears to have reported it on Twitter, but I'm not finding any sort of news item that definitively qualifies as a WP:RS at this time. --Kinu ^t/_c 23:00, 11 August 2014 (UTC)

Reported now, sadly: Emma Flanagan (12 August 2014). "Dame Kathleen Ollerenshaw former Lord Mayor of Manchester dies aged 101". Manchester Evening News. Retrieved 2014-08-12. . Deltahedron (talk) 06:31, 12 August 2014 (UTC)

Tech help required to improve categories

Please see Wikipedia:Village pump (policy)#CatVisor and User:Paradoctor/CatVisor#Planned features if you are willing and able to assist this innovative WP project move along it would be greatly appreciated. Thank you, IZAK (talk) 23:56, 12 August 2014 (UTC)

Wikidata inter language links

An editor has quoted in talk:quartic function that quartic function and quartic equation are two different wikidata items. This is normal, as these are different items, that may correspond, in some languages to different articles. However, as Quartic equation is a redirect to Quartic function, it seems natural to link both wikidata items to quartic function (possibly through a redirect). It seems impossible. This has the consequence, that most languages, which have only the equivalent of "quartic equation" have not the inter language link to the English article on the subject. Any idea to solve this problem that is certainly not specific to quartic equation/function? D.Lazard (talk) 11:01, 13 August 2014 (UTC)

Is it not possible to have the Wikidata item for quartic equation on the redirect page? Deltahedron (talk) 17:15, 13 August 2014 (UTC)

Moving inactive participants to the relevant list

I am writing a bot to move inactive users out of participants list (and add them to the relevant "inactive participants" list). Your list of participants is huge and my bot detects lots of inactive participants. With your consent, I will move them to the inactive list. The participants page says that inactive users "have either left the project or have not edited in the last three months." Should I keep the same criterion? My bot can also handle constraints like "not edited a page in the scope of the WikiProject in the last X months" or "not edited an internal page of the project (portal, project talk, ...) in the last X months". If I proceed, then I will most likely merge the sections of the table, but I think they can be easily restored by hand afterwards. Cheers. Pintoch (talk) 09:26, 15 August 2014 (UTC)

Curvature -> Curvature (mathematics)

This edit, although I have mixed feelings about it overall, got me thinking that perhaps the main link curvature should be the disambigation page and curvature should be moved to curvature (mathematics) over the redirect. As there's probably a lot of links coming in there, it seemed to me to be a good idea to raise the matter here in order to make sure that there is a solid consensus before inflicting the community with the inevitable hellstorm of disambiguation cleanup. S?awomir Bia?y (talk) 18:20, 12 August 2014 (UTC)

Hmm, the mathematical type of curvature seems the dominant type of curvature to me. Just googling for non-WP pages leads mostly to mathematical curvature topics, with a few pages on spinal curvature and image field curvature in optics. That edit seems to be an attempt to make the company a little more prominent, as it is already mentioned in the dab page. --Mark viking (talk) 20:54, 12 August 2014 (UTC)

I think that the output of a Google search is probably not the most accurate indicator of what the typical reader is expecting when they type "curvature" into the "Search" bar. But I will not insist too much on this point. S?awomir Bia?y (talk) 20:56, 12 August 2014 (UTC)

(edit conflict) Yes, I think WP:PRIMARYTOPIC applies, and that the mathematical meaning is clearly primary. A hatnote pointing to the disambiguation page is appropriate, but I don't see the need to mention the company separately in the hat. --David Eppstein (talk) 20:58, 12 August 2014 (UTC)

I removed the reference to the company and cleaned up the hatnote prior to seeing your post; glad to see we agree on that. --Kinu ^t/_c 21:04, 12 August 2014 (UTC)

I also agree that the hatnote should not mention the company and that the current article is the primary topic. --JBL (talk) 21:23, 12 August 2014 (UTC)

I think that the company is hardly the primary topic: indeed it's far from clear that it is at all notable. Its article appears to have been written by a single-purpose account with a name uncannily reminiscent of that of someone in the company's marketing department. Deltahedron (talk) 21:35, 12 August 2014 (UTC)

"the company is hardly the primary topic" You appear to be disputing a position taken by no one in this discussion. --JBL (talk) 21:38, 12 August 2014 (UTC)

I was under the impression that I was reinforcing the point by suggesting a reason why the company was not the primary topic. Deltahedron (talk) 21:41, 12 August 2014 (UTC)

Regardless of what was intended, I believe that the lack of notability of the company is something that should also be addressed in addition to the subject under discussion. S?awomir Bia?y (talk) 21:44, 12 August 2014 (UTC)

I too agree with the solution expressed in unanimity on this page, and I have advised the editor who made the initial/controversial edit to read WP:COI because the rest of his edits don't look very kosher either. JMP EAX (talk) 17:50, 15 August 2014 (UTC)

Autoparallel curve

There's vague def in parallel curve which makes a bit of sense but I can't find it in any reliable sources. That may happen because there's a deluge of sources about autoparallel curves in the sense defined in parallel transport (in reliable sources like [29], [30] or [31], Wikipedia fails to define autoparallel curves in there right now). Can anyone find references for the former meaning/def? The (unreferenced) material was added by an IP in 2004, so there's little chance of getting sources from him now. JMP EAX (talk) 16:58, 15 August 2014 (UTC)

Regarding the request for a formal definition, I would guess: "a curve is autoparallel if it is a nontrivial parallel of itself." I am not qualified to have an opinion about whether this is consistent with the word's use in some narrow corner of the literature, however. S?awomir Bia?y (talk) 19:12, 15 August 2014 (UTC)

Rather than guess, I would suggest removing the material which is unreferenced and unclear, particularly since it is in the introduction, which should simpply summarise what is already written, and referenced, in the main text of the article. Deltahedron (talk) 19:35, 15 August 2014 (UTC)

You have no argument from me on this point. I interpreted the original post in part as a genuine request for a formal definition (notice how the definition in our article is decorated with {{clarification needed}}s), rather than a request specifically for sources on the matter. S?awomir Bia?y (talk) 19:42, 15 August 2014 (UTC)

Now gone. --Salix alba (talk): 20:27, 15 August 2014 (UTC)

Thanks. I've also removed a small section later in the article about the same topic because it made no sense without the definition of "autoparallel". JMP EAX (talk) 21:20, 15 August 2014 (UTC)

And a related issue: Can anyone familiar with tubular neighborhood opine if the 3rd figure there is correctly depicting the concept? JMP EAX (talk) 19:06, 15 August 2014 (UTC)

Yes, there is nothing requiring the tubular neighborhood to be given by some particular exponential map. So I would say it is correct. However, I think a more useful illustration though would be of a tubular neighborhood of a curve on a surface, or at least a tubular neighborhood in which the red lines are replaced by more general non-intersecting curves. S?awomir Bia?y (talk) 19:20, 15 August 2014 (UTC)

Ok, thanks. JMP EAX (talk) 21:20, 15 August 2014 (UTC)

Bézier spline (vs. B-spline and polybezier)

This one is a mess because resulting from the morass of inconsistent terminology between authors. In general the latter two terms are consistently defined by those using them, but "Bézier spline" isn't. I've left some comments on the talk page there. More participation would not hurt, both in terms of comments and actually fixing the darn page... JMP EAX (talk) 21:20, 15 August 2014 (UTC)

An observation about quantifier complexity

An observation about Lebesgue's number lemma. It says:

If the metric space (X, d) is compact and an open cover of X is given, then

there exists a number ? > 0 such that every subset of X having diameter less than ? is contained in some member of the cover;

that is,

??>0 ?x?X ?? ?y?X ( |y-x|<? => y?U_? ).

Wow: a ???? formula! Does anyone remember a higher (or even equal) quantifier complexity?

Strangely, I did not find any discussion of such cases in "usual" mathematics (rather than math logic). I mean, the number of alternations of like quantifiers. Boris Tsirelson (talk) 21:23, 16 August 2014 (UTC)

The pumping lemma for regular languages is of the form "for all regular A, there exists a p such that, for all w, there exist x, y, z such that, for all i, ...". (I'm omitting all of the content, and leaving only the quantifiers.) See also Pumping lemma for context-free languages. You might classify this stuff as math logic though? I'd be surprised if we couldn't find really mainstream examples. Mgnbar (talk) 21:59, 16 August 2014 (UTC)

Indeed. By the way, Lebesgue's number lemma is (as far as I understand) a ????? formula, since the first quantifier is "for every metric space"; and the compactness probably is ???? (for every sequence there exists an accumulation point, whose every neighborhood contains...). But that may depend on the choice of one of equivalent definitions of compactness. Boris Tsirelson (talk) 12:03, 17 August 2014 (UTC)

"To grasp the meaning of ?x?y?z ?(x,y,z) is not so easy. In natural speech it is never used. When it is needed it is somehow circumvented. Consider, for example, the sentence:

In every town there is the tallest building.

...

To imagine the meaning of four alternations of quantifiers seems as difficult as to imagine four-dimensional space."

(Pavel Pudlák, "Logical foundations of mathematics and computation complexity", page 75.) Boris Tsirelson (talk) 12:18, 17 August 2014 (UTC)

"White has a forced checkmate in n moves" has a string of 2n+1 alternating quantifiers. According to http://timkr.home.xs4all.nl/chess2/diary.htm there is a position with KQP v KRBN that is a forced mate in 549 moves, giving well over 1000 alternations of quantifiers. r.e.b. (talk) 14:24, 17 August 2014 (UTC)

Yes, I know of this "cheap" way to get high quantifier complexity via games. But that is another story. Boris Tsirelson (talk) 18:49, 17 August 2014 (UTC)

This might be a stupid question

It is mathematically accurate to refer (in general) to a "set of formal languages"? Or does one usually need a class (set theory) for that? The CS literature varies widely in what it calls such a bunch: set/class/family are some terms I found. JMP EAX (talk) 16:01, 17 August 2014 (UTC)

A formal language is a set of strings over a fixed finite alphabet ?. Therefore each language over ? is a set. Further, each set of languages over ? is a set. For example, the set of regular languages over ? = {0, 1} is a set.

Textbooks and practitioners often omit mention of ? in stating theorems. They make statements such as, "The union of two regular languages is a regular language." Implicit in this statement is that the two regular languages are defined over the same alphabet. Or they may be defined over different alphabets, but then the union is defined over the union of the alphabets. Practitioners neglect such details because they are boring.

If you want to talk about the class of "all regular languages over all alphabets", then you have to let ? vary over all finite sets. So I believe that the question boils down to: Is the class of all finite sets a set? This is outside my expertise, but I'm guessing not.

Surely not. Boris Tsirelson (talk) 18:53, 17 August 2014 (UTC)

Consider the class S of all singleton sets, and the subclass R = { x ? S : ?x ? ?x }. Is {R} ? R? Deltahedron (talk) 19:23, 17 August 2014 (UTC)

This is all in relation to some article editing? Mgnbar (talk) 16:53, 17 August 2014 (UTC)

+----------------------------------------------------------------------------------------------------+ E.g. one can read in a book the following def(s):

1. A set L of languages is mildly context-sensitive iff
a) L contains all context-free languages.
b) L can describe cross-serial dependencies: There is an n >= 2 such that {w^k |w ? T^*} ? L for all k <= n.
c) The languages in L are polynomially parsable, i.e., L ? PTIME.
d) The languages in L have the constant growth property.
2. A formalism F is mildly context-sensitive iff the set {L|L = L(G) for some G ? F} is mildly context-sensitive.

(As an aside: "Formalim" is not formally defined in that book as far as I can tell, but apparently the author can formally write membership in it with "?" regardless. Also, the "constant growth property" is defined in a def after that one [not before]. So it all kinda rings alarm bells of rather sloppy writing to me.) JMP EAX (talk) 17:15, 17 August 2014 (UTC)

I don't know that material, but perhaps there is some fixed ? that's going unmentioned, as I described above. For example, the definition mentions P (complexity), and I think that a fixed ? is implicit in that definition. Or maybe not, and nobody cares?

If these questions are not in relation to planning or editing Wikipedia math articles, but rather for your curiosity or work, then please raise them at Wikipedia:Reference desk/Mathematics instead of here. Mgnbar (talk) 17:57, 17 August 2014 (UTC)

We allow some latitude here in discussions here, especially for discussions on topics like this, the language used to describe mathematical objects. After all, we need to understand how the language we're using works before we can write the articles. Deltahedron (talk) 18:07, 17 August 2014 (UTC)

Up to isomorphism, every finite alphabet is a subset of the natural numbers, every string is a sequence of natural numbers, every language is a set of strings, and the collection of all languages forms a set. So there's a perfectly valid way of talking about "the set of all languages". My suspicion is that the people who work in this area tend not to care enough about foundations to care whether they're doing things up to isomorphism or over all finite alphabets, nor whether using all alphabets causes these things to become a proper class rather than a set. --David Eppstein (talk) 18:46, 17 August 2014 (UTC)

Indeed from the class article Outside set theory, the word "class" is sometimes used synonymously with "set". I guess that might be the case here.--Salix alba (talk): 19:19, 17 August 2014 (UTC)

David Eppstein's answer is basically what I thought I understood of this issue, i.e. for a fixed alphabet (or up to equivalence classes [isomorphisms] thereof) one can speak of the set of languages (e.g. [32]), but otherwise [over all possible alphabets] it's improper to speak of a set... Some authors probably have the best punt when they use neither class nor set but "family" [33]. JMP EAX (talk) 20:14, 17 August 2014 (UTC)

Searching Google Books for a similar expression such as "the set of Turing machines" (Find sources: "the set of Turing Machines" - news · newspapers · books · scholar · HighBeam · JSTOR · free images · free news sources · The Wikipedia Library · NYT · WP reference) finds plenty of examples where it's used in the general sense, presumably glossing over or taking as self-understood the fixing [or taking equivalence classes of] the alphabet, states etc. JMP EAX (talk) 20:42, 17 August 2014 (UTC)

By the way, I assumed that the original poster's question was not "up to isomorphism". Then clearly the set of all finite sets is just the set of natural numbers. Mgnbar (talk) 21:10, 17 August 2014 (UTC)

Heh, the article in question just got nuked from space (entirely rewritten). JMP EAX (talk) 21:48, 17 August 2014 (UTC)

René François Walter de Sluse

Would someone who understands the maths please merge René-François de Sluse and René François Walter de Sluse? Andy Mabbett (Pigsonthewing); Talk to Andy; Andy's edits 17:12, 19 August 2014 (UTC)

Boxcar function and Crenel function

Boxcar function and Crenel function have been tagged for a merger since March 2014. There is no discussion on the talk pages. -- Alan Liefting (talk - contribs) 21:48, 19 August 2014 (UTC)

Kleene algebra

Can someone suggest good parentheticals to add to add to the disambiguation(s) for Kleene algebra? I'm thinking that the first one (in the order given on that page) should perhaps be called

Kleene algebra (De Morgan algebra) or Kleene algebra (with involution)?

while the 2nd one should could perhaps be called

Kleene algebra (with closure) or Kleene algebra (regular expression generalization)

Any other ideas? I think the first one probably only needs to redirect to De Morgan algebra presently, because the rest of the article doesn't cover it.

Any other suggestions? JMP EAX (talk) 17:35, 20 August 2014 (UTC)

Fields Medal Table

I prepared a new table to replace with current one in Fields Medal page.I want to hear your invaluable comments about it.here it is:

Discussion

There seems to be a editing dispute at Fields Medal in which multiple parties have reverted each other over the table issue. That article is now even fully edit-protected. It might be helpful if someone could summarize what the difference between these tables is, and why it matters so much. Just posting one of the two versions of the tables here does not convey much information about the difference. Also, I think we need to understand why the matter was so controversial as to demand canvassing this over multiple user talk pages. S?awomir Bia?y (talk) 12:51, 19 August 2014 (UTC)

@S?awomir Bia?y Thank you for your attention. Canvassing is the result of my fault.Sorry for that.I don't want to be disruptive,and of course,there is not an urgency or anything else. The major differences between this table and previous versions are:1)in the old table,there was no information about fields medalists current institution(s),2)The current table which is now fully edit-protected, contains some wrong and weak information(e.g. It states that many of medalists were born in USSR, which has been dissolved,instead of stating for example that they were born in today Russia),3)Both the old and current versions of table sorely lack in terms of reliable reference.These are main reasons.There is no big deal,So do not rush yourself into it and take your time.Thank you.Rezameyqani (talk) 13:49, 19 August 2014 (UTC)

On the issue of flag icons and country links, the icon should correspond to whatever country existed at the time. So I agree with keeping USSR as the flag icon in most of the entries at the current protected version of the article. To me the links to the Kingdom of Prussia make no sense at all. All of the German born mathematicians were born in Germany, period. As for Klaus Roth, the Kingdom of Prussia is equally inappropriate. He was born Wroc?aw, which was then part of Germany (even though now it is part of Poland). S?awomir Bia?y (talk) 14:22, 19 August 2014 (UTC)

@S?awomir Bia?y Thank you for your time. As you probably know,former USSR was consisted of several soviet republics.all of them were autonomous.So,I think when we say,for example Voevodsky was born in Russian SFSR,it clearly implies that he was born in USSR.about Prussia,one of these mathematicans were born in Free State of Prussia,Grothendieck and Roth.the problem was that I could not find the proper flagicon for Free State of Prussia.Rezameyqani (talk) 14:49, 19 August 2014 (UTC)

The Free State of Prussia was a state of the German Reich, that is, Germany. Likewise Russia was a state of the USSR. We don't list states as birthplace generally. Charlie Fefferman was born in Maryland, but we list his birthplace as USA. Why should other geopolitical subdivisions be given special treatment, especially when there is no obvious benefit? S?awomir Bia?y (talk) 15:08, 19 August 2014 (UTC)

Your logic clearly convinced me.I will change birthplace flagicon of Grothendieck and Roth to German Reich and all mathematicians who were born in USSR,to flagicon of USSR.Would you find this change logical? Rezameyqani (talk) 15:15, 19 August 2014 (UTC)

So if you address the flag icon and country links, what differences remain between your version and the one appearing in the article? S?awomir Bia?y (talk) 20:48, 19 August 2014 (UTC)

@S?awomir Bia?y The current table does not give any information about current institution of medalists. Also the information on the current table does not cite any sort of references.Rezameyqani (talk) 06:25, 20 August 2014 (UTC)

Ok, although the existing table does have information about the current institution, I prefer the way you have done it (with flag icons beside the institution names). Would it also make sense to include flagicons beside the Institution (at the time of receiving the medal) field? Or would this just be too many icons? As for the references, it's a little unclear to me what purpose the references serve here. Are they meant to refer only to the "current/last institution" field of the table? That's how I interpret them, and I think that this column of the table probably has the greatest need for references. Presumably the rest of table can for the most part be referenced as a whole to some other source such as http://www.mathunion.org/general/prizes/fields/prizewinners. You might want to make this explicit somehow. S?awomir Bia?y (talk) 11:32, 20 August 2014 (UTC)

@S?awomir Bia?y Your interpretation about the use of references are true.I put references to clarify the current affiliation. Also,Yes, putting more flags in the table would make it a messy.Rezameyqani (talk) 12:42, 20 August 2014 (UTC)

Ok, then just to summarize: in the birthplace/ICM fields, only include the flag icon of the country that existed at the time. You might consider including an explanatory statement about the references, and a general reference that covers the rest of the content of the table. Otherwise, the new table is fine by me. S?awomir Bia?y (talk) 13:03, 20 August 2014 (UTC)

Error: The flag icon for Columbia University appears to be Russia, but it should be the USA. S?awomir Bia?y (talk) 13:05, 20 August 2014 (UTC)

With regard to birthplace column,I think it would be better for countries that have been formed after dissolution of USSR,We mention the new country's flag.Same goes for Weimar republic or West Germany.Thank YouRezameyqani (talk) 14:33, 20 August 2014 (UTC)

I thought we had already discussed this. The country of birth should obviously listed as whatever country existed at the time. Any other designation would be an ahistorical anachronism. S?awomir Bia?y (talk) 14:57, 20 August 2014 (UTC)

@S?awomir Bia?y You're right.I looked at some of the medalist's CVs,and they mentioned their birthplace exactly as what you said.Would you mind correcting this error yourself?Thank YouRezameyqani (talk) 15:03, 20 August 2014 (UTC)

I wanted to add, but had an edit conflict: a firm position on this also helps to ensure a neutral point of view. Nationality designations are notoriously prickly on Wikipedia. S?awomir Bia?y (talk) 15:10, 20 August 2014 (UTC)

~~And If it is possible for you,correct these flags on the table which exists on Fields Medal talk page,OK?Thank buddy.~~ I just made corrections and updated the table.hope you approve it.ThanksRezameyqani (talk) 15:05, 20 August 2014 (UTC)

The version that appears above now looks very well done to me. I have no further comments at the moment. S?awomir Bia?y (talk) 11:10, 21 August 2014 (UTC)

Why are there flags at all? By the guideline MOS:FLAG none are needed. They should only appear when the subject represents a country - a national team for example, or the country itself. They should also include the county name as it's often non-obvious from the icon what the country is. So these are both unnecessary and incomplete. None are needed; if someone reading doesn't know and wants to know what country Oslo is in, or the University of Helsinki, or Harvard University they can click on those links. See also MOS:FLAGS#Do not use too many icons - the above table is far worse than the example they give as excessively cluttered and redundant icons. They also result in massive overlinking, giving e.g. dozens of links to United States. There are much better ways to indicate the number of medals per country, such as has been done at Fields Medal#Landmarks.--JohnBlackburne^words_deeds 11:43, 21 August 2014 (UTC)

It would have been better to have this discussion at Talk:Fields Medal#RFC. I, for one, am only now seeing it. Check out at my latest suggestion there and see what you think. I am not married to flags, as some of my comments there make clear, but I do see a potential benfit to having flags in front of the institution names, as I have alluded to over there. As for the separate "Landmarks" by-country table, I think it gives more emphasis to the countries than just having flags in the one table does. But that's just my opinion... In any case, please discuss this table on the talk page of the article where the table belongs. - dcljr (talk) 12:29, 21 August 2014 (UTC)

letter to the Foundation

Not exactly math, but maybe of interest for some here that followed the recent struggle of the foundation with parts of the community and/or dislike the curret decision making process or the media viewer:

m:Letter to Wikimedia Foundation: Superprotect and Media Viewer/en

--Kmhkmh (talk) 11:41, 21 August 2014 (UTC)

This is related, of course, to the ongoing discussion in the above thread. S?awomir Bia?y (talk) 13:19, 22 August 2014 (UTC)

Time Cube

Is Time Cube within the scope of WikiProject Mathematics? See diff. Johnuniq (talk) 02:33, 23 August 2014 (UTC)

It should be very obvious that it is not. The article should be deleted promptly. YohanN7 (talk) 03:11, 23 August 2014 (UTC)

Why? The web site is nonsense, of course, but that doesn't prevent it from being notable. And are mathematical cranks not something we should concern ourselves with here? --David Eppstein (talk) 04:31, 23 August 2014 (UTC)

What then is a notable mathematical crank? The article on Myron Evans is gone. He, if anyone, is a notable crank. YohanN7 (talk) 05:09, 23 August 2014 (UTC)

Mathematical crankery, on such topics as angle trisection, is certainly notable, and the subject has been covered in serious books from De Morgan to Underwood Dudley. It should also be within the purview of this project. It follows that individual cranks or crankeries might well be notable simply for their crankishness, if they or their crankeries are covered in independent reliable sources such as Dudley's books. Indeed, some cranks are notable for other reasons as well. Incidentally, please be sure to distinguish mathematical crank (person) from crank (mathematics) and crank conjecture from the crank conjecture! Deltahedron (talk) 06:12, 23 August 2014 (UTC)

In answer to Johnuniq's question, I'd say that it is clearly not within scope, considering the site's content. David, let's also not confuse the person with the site: the site is the subject of the article (so we'd have to rename the article to Otis Eugene Ray to justify not deleting it). --Quondum 15:50, 23 August 2014 (UTC)

Not a maths crank so not in the purview of this project. Could possibly be considered a phyics nutter though. Dmcq (talk) 16:23, 23 August 2014 (UTC)

Problematic redirect: Cantor's paradise

Currently, Cantor's paradise redirects to set theory#Axiomatic set theory.

Not meaning to offend anyone, this does not appear to me to make much sense. Cantor's set theory was famously not axiomatic (whether it was "naive" depends on just what you mean by that, and that's another whole hornet's nest that needs to be addressed, particularly at Russell's paradox, but that's not what I came to talk to you about today).

It seems to me that there are about three things that could be done with it.

It could be deleted. That actually seems like a reasonably good option to me, compared to the alternatives.
A brief article could be written on David Hilbert's famous quote, which introduced the phrase.
An article could be written on the conceptual basis of set theory, and this term redirected there. (No, that article is not naive set theory, which is a seriously problematic article, largely because it's not clear which of the several interpretations of that phrase the article is supposed to be about.)

Thoughts? --Trovatore (talk) 02:53, 21 August 2014 (UTC)

The alternatives are not at all bad. As for me, (2) is better than (1). About (3), it is definitely better than (2) provided that you are ready to write such article! Boris Tsirelson (talk) 05:30, 21 August 2014 (UTC)

(2) [maybe call it (2 minimal)] could be simply a redirect to David Hilbert and mention the phrase there. If enough material accumulates, one could then split it to an article. JMP EAX (talk) 07:14, 21 August 2014 (UTC)

That's not bad. --Trovatore (talk) 07:15, 21 August 2014 (UTC)

Regardless of where the paradise redirects to, the Hilbert quote should certainly be included at set theory! Tkuvho (talk) 07:24, 21 August 2014 (UTC)

Some possible sources with varying degrees of praise and criticism: [34] [35] [36] [37] [38] JMP EAX (talk) 07:31, 21 August 2014 (UTC)

Based on the various commentary in 2nd-ary sources it seems to me the phrase relates more to Cantor's concept of infinity rather than his concept of set. Although some do interpret it in that sense too. JMP EAX (talk) 07:36, 21 August 2014 (UTC)

I have seen (I think) Von Neumann universe being referred to as Cantor's paradise. It makes some sense. YohanN7 (talk) 11:35, 21 August 2014 (UTC)

Following what JMP EAX said, see Tav (number) and Absolute Infinite. JRSpriggs (talk) 13:57, 21 August 2014 (UTC)

What do reliable sources say? One possibility is Ferreirós, José (2008). Labyrinth of Thought: A History of Set Theory and Its Role in Modern Mathematics (2nd revised ed.). Basel: Birkhäuser. ISBN 3-7643-8350-X. Zbl 1119.03044. . Deltahedron (talk) 14:20, 21 August 2014 (UTC)

The book by Ferreiros seems carefully researched and would be a good basis for a short article on Cantor's paradise. One could mention that Cantor's paradise is an expression used by Hilbert in describing set theory and infinite cardinals developed by Cantor. The context of Hilbert's comment was his opposition to what he saw as Brouwer's reductive attempts to circumscribe what kind of mathematics is acceptable. Here one could provide a link to the "Brouwer-Hilbert controversy" page which is unfortunately in sad shape. Anyway the main purpose of the page would be to provide some historical context for the term and also to provide links to pages like Hilbert and Brouwer and set theory. Any objections? Tkuvho (talk) 09:10, 24 August 2014 (UTC)

Decidability of the first-order theory of the real numbers

Decidability of the first-order theory of the real numbers could use some work. Michael Hardy (talk) 12:32, 24 August 2014 (UTC)

According to the current contents this should be "decidability of first-order theories", without the definite article. Tkuvho (talk) 12:44, 24 August 2014 (UTC)

IMO this article must be merged with Tarski-Seidenberg theorem, which is about the proof of this decidability. D.Lazard (talk) 14:16, 24 August 2014 (UTC)

Issue in Fréchet mean

Please see Hermann Karcher's unanswered complaints from a month ago in Talk:Fréchet mean (and see also Karcher's arXiv preprint, linked there, for more detail). Karcher seems to object to the terminology "Karcher mean", preferring an older name "Riemannian center of mass". But it is unclear to me exactly what scope these names are supposed to have (metric spaces or Riemannian metric spaces?), whether Karcher's work really does concern the local-vs-global difference from the Fréchet mean that the article now ascribes to him (Grove and Karcher 1973 seems to be about uniqueness of minima in certain Riemannian spaces), or what the right name should be. Karcher recently contacted me by email asking for help getting this resolved. Perhaps someone with more expertise than me in these areas can help clarify this. --David Eppstein (talk) 23:34, 24 August 2014 (UTC)

I've cited a couple of papers that use the term, and I suspect that many more could be found. But I don't know what that implies under Wikipedia policy. So we could still use some help there. Mgnbar (talk) 00:17, 25 August 2014 (UTC)

It is perhaps also worth noting that the Definition section of the article is in incredibly poor shape and badly needs to be rewritten for clarity of writing, punctuation, mathematical English, and clarity of notation. (I am on mobile so am not able to easily do it myself.) --JBL (talk) 01:50, 25 August 2014 (UTC)

List of things named after members of the Bernoulli family

The new List of things named after members of the Bernoulli family could probably use some work. Which member of the family was each thing named after? If it were a long list, it could be divided into secctions by subject matter; with a list as short as this one, maybe a brief comment on each item could be included. Michael Hardy (talk) 15:33, 25 August 2014 (UTC)

In its current form, I don't see how this isn't redundant to the Mathematics subsection at the Bernoulli disambiguation page. --Kinu ^t/_c 18:09, 25 August 2014 (UTC)

I would suggest merging it into Bernoulli family, which already basically duplicates the same list. bd2412 T 18:16, 25 August 2014 (UTC)

One difference from the dab page is that a list (as a separate article or in the Bernoulli family) can contain entries that would not reasonably be the target for a wikilink to "Bernoulli". These entries should not be included in a disambiguation page. Some possible such links include Euler-Bernoulli beam theory, Poly-Bernoulli number, Time-inhomogeneous hidden Bernoulli model, etc. --David Eppstein (talk) 18:53, 25 August 2014 (UTC)

Variation (combinatorics) proposed for deletion

Is the article titled Variation (combinatorics) worth keeping? And should it say that the chosen elements are distinct? Michael Hardy (talk) 13:23, 24 August 2014 (UTC)

I PRODed the article because I think that it is essentially WP:OR. The editor who created the page said (Talk:Combination#Militant ignorance against vairations) that until he created the page some Russian wikipedians were unable to find an English equivalent to the term they were using. I think that this is essentially correct, there is no common English term used to simultaneously refer to k-tuples and k-permutations (partial permutations), at least not in my extensive set of references on combinatorics. I believe that the term was made up to fill this hole in translation, and so, would not have any reliable secondary sources, hence the PROD. As an aside, if you make a statement about the distinctness of the elements you would lose one of the two meanings of the "proposed" term. Bill Cherowitzo (talk) 16:07, 24 August 2014 (UTC)

This book shows historical use of the term variation for m-permutations. Given the term exists, a redirect would be preferable to a deletion. --Mark viking (talk) 17:02, 24 August 2014 (UTC)

I can't really speak to use of the term in English but in German in it is common/standard term (see de:Variation (Kombinatorik). Should the term occasionally appear in (older) English literature as well, a redirect or rather a link from the disambiguation page for variation might be appropriate.--Kmhkmh (talk) 17:25, 24 August 2014 (UTC)

Thanks for that reference Mark. While it still doesn't give us an early English source (I don't think Bernoulli wrote in English ) it does change my opinion about this page. A redirect is slightly problematic since there is no single topic to point this to, so I'd prefer the link from the disambiguation page for variation. This link would permit splitting off variations with repetition from variations without repetition. I think this should be done even without any proof of archaic English usage, since the term is currently used in this way in German (my sole German combinatorics book does not use the term, so I missed this). Bill Cherowitzo (talk) 04:23, 25 August 2014 (UTC)

Done, as a redirect to a disambiguation page (may the Disambiguation Gods forgive me). Bill Cherowitzo (talk) 19:46, 25 August 2014 (UTC)

Commutative property

A good article (or even appropriately titled)? Discuss. I should mention that I lambasted this wikipearl on Jimbo's talk page. JMP EAX (talk) 01:58, 26 August 2014 (UTC)

I should note that the same anti-*ivity campaign was apparently carried out on another page given how an old version looked like [39]. JMP EAX (talk) 02:13, 26 August 2014 (UTC)

Disambiguation help needed with Antisymmetric

Expert attention is needed in figuring out about a dozen and a half incoming links to Antisymmetric, which has recently been made into a disambiguation page. I am wondering whether it would be possible to write a general concept article on antisymmetry in mathematics to which links could generally be pointed. Note that Skew-symmetric and Skew symmetric also pointed here, but I retargeted both of those to Skew-symmetric matrix, as it is the only article that is a title match to these terms. Hopefully that was the right answer to that problem. Cheers! bd2412 T 02:50, 25 August 2014 (UTC)

I think you overlooked the existence of Skew-symmetric graph, Skew-symmetric form (redirect to Bilinear form) and Skew-symmetric tensor (redirect to Antisymmetric tensor). I would suggest Skew-symmetric and Skew symmetric be re-redirected to Antisymmetric, as should Skew symmetry. Deltahedron (talk) 08:03, 25 August 2014 (UTC)

In addition, the heading of Antisymmetry should link to Antisymmetric, or possibly move Antisymmetry to Antisymmetry (linguistic) and move and redirect Antisymmetric to Antisymmetry as the main disambiguation page. Deltahedron (talk) 08:32, 25 August 2014 (UTC)

I agree that antisymmetry should probably be moved to antisymmetry (linguistics). S?awomir Bia?y (talk) 11:21, 25 August 2014 (UTC)

@Deltahedron, note that Antisymmetric and Skew-symmetric may be synonyms for some purposes, but are not homonyms. If Skew-symmetric has multiple meanings itself then Skew-symmetric should be either its own article (if the meanings are related) or its own disambiguation page (if the meanings are unrelated). bd2412 T 12:42, 25 August 2014 (UTC)

I have no problem with a separate disambiguation page for skew-symmetry. Deltahedron (talk) 12:51, 25 August 2014 (UTC)

The question still remains whether there is a general concept of Skew-symmetry. Does the term "skew-symmetric" mean something different and unrelated in Skew-symmetric graph, Skew-symmetric form, and Skew-symmetric tensor, or is it possible to describe a single general concept of skew-symmetry that explains all of them? Also, if these are going to be disambiguation pages, the links will need to be fixed. bd2412 T 13:40, 25 August 2014 (UTC)

I think there is: skew-symmetry is a property of structures that have some notion of sign, and an involution which changes the sign. For example, a skew-symmetric graph has an involutions that reverses all arrows; a skew-symmetric matrix has an involution (transposition) which changes the ± sign on all the matrix entries; a skew-symmetric form is a function of two variables which changes sign on interchange of the variables. Anti-symmetry is vaguer, but one might describe it as a property of structures with a Boolean set of values which reverse under the involution. For example, an anti-symmetric relation is one which if is true for the terms in one order is false when the terms are interchanged. However this is all a personal opinion. Deltahedron (talk) 13:53, 25 August 2014 (UTC)

There must be sources describing these things (after all, there must be some basis for the development of your opinion on the matter). Note that NIST defines skew symmetry as: "The property that the flow is the same amount, but reversed direction, starting from either vertex of every edge of a flow network. More formally, for an edge e=(v,w), f(v,w) = -f(w,v), where f(a,b) is the flow from a to b". bd2412 T 15:07, 25 August 2014 (UTC)

That would seem like a rather specialized use of the term, not in accord with the way it is used in much of mathematics. So I don't think that's much of a foundation on which to build an article on the general concept. S?awomir Bia?y (talk) 21:32, 25 August 2014 (UTC)

Frankly, I am having a hard time finding much about it as a concept. Suppose we have an article on the general concept of Antisymmetry (mathematics) and discuss the distinction between antisymmetry and skew symmetry there, to the extent that there is a difference that can be sourced? That would also solve the problem of incoming links, since that all seem to be math-related. bd2412 T 22:28, 25 August 2014 (UTC)

Is there a difference? As far as I know, these are synonyms. What exactly is being proposed here? If we can't find an authoritative source that treats various notions of skew-symmetry (or antisymmetry) as a whole, then probably there shouldn't be an article on that subject. We shouldn't have an article just in order to have something for ambiguous links to point to. S?awomir Bia?y (talk) 23:05, 25 August 2014 (UTC)

I don't want to force a square peg into a round hole here (sorry, topology joke), but it seems that the antisymmetry in effect in an antisymmetric matrix is the same kind of antisymmetry in effect in an antisymmetric relation or an antisymmetric tensor. If not, then the many math articles linking to antisymmetric need those links fixed (and the same for skew-symmetric cases), because readers following those links will have a hard time finding the right option on a disambiguation page. If they are related, then the relationship itself can be described both in terms of its functionality and in the history of its discovery and development. I rely on the experts here to determine the optimum solution. bd2412 T 03:05, 26 August 2014 (UTC)

@S?awomir Bia?y: but we do have such articles for example Self-adjoint, center (algebra) or centralizer. It think this is what WP:SIAs are for. JMP EAX (talk) 06:46, 26 August 2014 (UTC)

But I don't think these are analogous. For instance, basically all uses of "self-adjoint" come from the usage in star algebras, so that is the primary meaning. An SIA is fine as a list in this case, but I really don't think there is enough here to write an article on. Any article in this case would almost certainly be very bad. S?awomir Bia?y (talk) 10:35, 26 August 2014 (UTC)

Bad redirect

Super linear algebra is now a redirect to linear algebra. Anyone looking for information on super-anything will only be frustrated by such a redirect. It would be better if it was just a red link. YohanN7 (talk) 17:05, 29 August 2014 (UTC)

I made it into a redirect to Super vector space. Better than nothing. JRSpriggs (talk) 18:01, 29 August 2014 (UTC)

Our article superspace should really include a disambiguation note (indicating the other common usage of superspace as the opposite of subspace). I wonder also if there is a possibility of confusion with "super vector space" or (worse) "vector superspace". S?awomir Bia?y (talk) 18:28, 29 August 2014 (UTC)

Mathematics under Flow

I have been trying out mw:Talk:Sandbox to see how mathematics renders inside Flow. It doesn't seem to be working to well for me: has anyone else tried it recently? Reports at Wikipedia talk:Flow, not here, I suggest. Deltahedron (talk) 19:42, 29 August 2014 (UTC)

Mathematical Reviews and Zentralblatt MATH

There is a discussion taking place, regarding a proposal, which I think might be of interest to this project and community.

The discussion is taking place on the talk page of Notability (academic journals). ---Steve Quinn (talk) 04:18, 29 August 2014 (UTC)

The talk page you've linked was last edited more than 1 year ago; the particular section that you've linked seems to be 3 years old. Did you mean to link something else? JBL (talk) 06:08, 29 August 2014 (UTC)

Probably Wikipedia_talk:Notability_(academic_journals)#Mathematical_Reviews_and_Zentralblatt. Deltahedron (talk) 06:13, 29 August 2014 (UTC)

The context is Wikipedia:Articles for deletion/Mathematics and mechanics of complex systems. --David Eppstein (talk) 06:51, 29 August 2014 (UTC)

Sorry about the wrong link - I was probably tired when I posted it. Thanks to the two editors who posted the corrections. -- Steve Quinn (talk) 05:53, 30 August 2014 (UTC)

A response from WMF

Assiduous readers here will recall that, following a challenge from Jimmy Wales, there was a discussion here about what we might want from WMF in the way of mathematics rendering and editing. I sent a summary of that discussion to Jimbo Wales, who responded that he had "copied this text to the Board wiki and emailed the board (and Lila) asking them to read it" and would "personally recommend that we allocate resources to this" [40]. I have just had a discussion with Rachel diCerbo, Director of Community Engagement (Product) at WMF and have to report that she has told me that "It's one of those things that is "on the radar" but for now I don't imagine that we would be able to put it on the roadmap for the foreseeable future" [41]. It's very disappointing, especially since the proposal had Jimmy Wales's backing, and I'm sorry not to be able to deliver better news. However, I suppose that at least we know where we stand now -- WMF are not going to allocate resources to improving mathematics editing and rendering software in the near future, not are they going to include it in their planning. Rachel mentions James Forrester as "the Product Manager responsible for this area" but without resources it seems hard to see what there might be to discuss with him. In short, it does not appear that mathematics has a future here. Deltahedron (talk) 16:38, 19 August 2014 (UTC)

This is misleading, to put it mildly. Mathematics coverage continues to have a strong future at Wikimedia, but the strength of that future continues to be based on what the community of interested individuals wishes to put in. It would be good to see some people engaging with and helping the other excellent, hard-working volunteers who have toiled away to give you the tools you have today, as well as those to come. Instead, so far mw:Extension talk:Math/Roadmap merely has a copy-pasted list of passively-given complaints, without any sign that people want to actively help make changes and improve things. Code is not written by magic fairies. It's written by real people. It'd be wonderful to have some positive engagement here. Jdforrester (WMF) (talk) 16:54, 19 August 2014 (UTC)

"Misleading" is a strong term, I reject it, and you should withdraw it. I have done my best to represent the discussion as I see it and have given a link to the conversation on meta for the interested. The result of this discussion is that mathematics rendering and editing has no place in the WMF roadmap, and the WMF with over 100 employees and income in the tens of millions of dollars has not resources to allocate it, nor does it propose to include mathematics editing in its planning process (nor does it currently have a mecanism to do so). The content of the encyclopaedia is not written by magic fairies either. It's written by volunteers, many of them experts, for free. For a paid employee to come here and tell people who are contributing to the project, for free, by writing the encyclopaedia, that if they wish to be able to continue to do so, the way to do that is that they have to become unpaid developers as well, is -- unhelpful. Deltahedron (talk) 17:02, 19 August 2014 (UTC)

Having said which, let me pick up a couple of points to see if there's a way forward. Assuming that these volunteer developers do come forward, where is the locus for the discussion between what the editors and readers might want or need, and what those volunteers might want or be able to work on? Is it mw:Extension talk:Math/Roadmap? James is rather scornful of the "copy-pasted list", which I might mention was the compilation of discussions at this and similar pages, and the same list that Jimmy Wales was so enthusiastic about, as noted above. What was wrong with it? Is that the right place? If not, where is? Do WMF staff want to involve themselves in the conversation there, or is it solely between one group of vounteers and another? Is that where WMF staff will alert us to impending changes in other bits of software that might affect us, or will they use some other channel? What is the way forward, according to WMF? Deltahedron (talk) 18:13, 19 August 2014 (UTC)

@Deltahedron: I believe that there are slightly fewer than 60 software engineers at WMF, out of 208 staff overall (I could be wrong - seer the list on Foundation wiki). My team of six(-ish) people are the ones working on tools for editing - everything from formulæ to VisualEditor to hieroglyphics to citations to sheet music to... The rest work on areas like performance, discussions ("Flow"), multimedia, mobile phone, tablet and native app support, languages, and stopping the site from falling over. You're welcome to lobby senior management to increase the number of people working on editing tools so that we could dedicate some paid developer time to mathematical support, but characterising it as a straight choice between supporting and not supporting your particular editing requirement isn't entirely fair. :-)

On how to engage with fellow volunteers, there's nothing 'wrong' with copy-pasting a complaint, but it's unlikely to get things to happen compared to actually talking these things through with the people that can help you. I find that an isolated discussion on one wiki - even a wiki as important as enwiki - is often not very useful in getting stuff done. Jdforrester (WMF) (talk) 18:59, 19 August 2014 (UTC)

I am sorry to hear that WMF has such a small paid staff of engineers at its disposal. We have precisely zero paid staff here at WPM. This discussion is precisely because I did lobby senior management for more support for mathematics editing, and the result was, as described above, disappointing, if not exactly a huge surprise. Of course everyone here realises that things have to be prioritised, I really do not think you need to explain that. You have described what is not very useful to get things done. What, then, in your opinion, should we do to increase the probability of getting the thing we think need to be done? Who are these people who can help us, and where do we go to talk these things through with them? Deltahedron (talk) 19:08, 19 August 2014 (UTC)

Additional. You describe this as a "complaint". That's rather disimissive. It's a summary of a constructive discussion across three languages, in response to a specific request by Jimmy Wales and subsequently described by him as "a very helpful and concise statement of the issues and concerns". The fact that you dismiss it as a complaint suggests that perhaps you did not actually read it carefully? Deltahedron (talk) 19:13, 19 August 2014 (UTC)

@Deltahedron: I'm talking about this copy-and-paste, FWIW. I don't see "complaint" as a "dismissive" term, and I'm again disappointed that you try to twist my words like this; it's just an observation that giving people a list of demands (do this, then do this, finally do this) is forum-shopping, not real engagement with people.

There is no "why" in what you pasted, no actual discussion of what was on the roadmap to which you were posting, it was clearly written for another audience (you do realise that you posted a list of demands to WMF on a page aimed at volunteer developers, right? Surely you can imagine how demoralising/marginalising that would feel to those volunteers?)

As to the best way to engage with fellow volunteers, I can't speak for them as to what works best, I can just advise on what often doesn't work. Have you asked them how they would like you to engage with them? Jdforrester (WMF) (talk) 20:09, 19 August 2014 (UTC)

I am unable to regard this as a helpful answer. It is quite astonishing that the Product Manager, VisualEditor team, with a remit "to ensure that his "team understands what the community wants and needs, is focussed on the things that matter, and is engaging with and understood by the community" is quite ignorant of how and where to effectively engage with a group of volunteers, and is unable to suggest anyone who might be able to help. Let me just quote my question and your answer together

"Who are these people who can help us, and where do we go to talk these things through with them?"

"Have you asked them how they would like you to engage with them?"

This may strike you as amusing but it is unworthy of someone in your position. Now please may we have a considered answer to the question? Deltahedron (talk) 20:22, 19 August 2014 (UTC)

@Deltahedron: For the tenth or eleventh time, the Roadmap page to which I directed you last month is probably the best venue. For which volunteers are best to talk to, I don't know for sure, but looking at this history page suggests mw:User:Physikerwelt and mw:User:Schubi87. Your continued grossly bad faith responses like this make me sad. Jdforrester (WMF) (talk) 20:28, 19 August 2014 (UTC)

ping User:Physikerwelt so he knows about this discussion. (I guess cross-wiki pings like the link to mediawikiwiki above don't work). --Jeremyb (talk) 06:35, 22 August 2014 (UTC)

pong. I'm waiting for code review here [42]. I think we are on a good way here. I'll come back once the change is merged and the new Math rendering can be tested at beta-cluster. (I can be tested at the moment but does not work). I proposed to establish a mentioning system for volunteers (i.e. extension maintainers) to Quim Gil. I'm waiting for a reply here. I think it's essential that there is exactly one fixed point of contact on the WMF side for every extension used in production. --Physikerwelt (talk) 15:42, 22 August 2014 (UTC)

Good news, and thanks for all the effort you've been putting in on this. Deltahedron (talk) 16:00, 22 August 2014 (UTC)

"Probably"? You mean you don't know where or how volunteer effort is coordinated? Deltahedron (talk) 20:35, 19 August 2014 (UTC)

@Deltahedron: I don't know for sure, no. I'm not in a position to order volunteers around, and that includes telling them where and how to congregate. I can merely observe and intuit based on what looks sensible. Do you think instead I should try to tell volunteers that they can only participate in venues I run? That doesn't seem very wiki like or respectful. Jdforrester (WMF) (talk) 21:19, 19 August 2014 (UTC)

I would expect that you would know where and how volunteer effort is coordinated and conducted, so that you may effectively advise volunteers about what is and is not a good use of their time and energy, and so that once work is done, you can most efficiently integrate it into the code base. Restricting yourself to observing seems an ineffective way of doing your job of engaging with the community. The dichotomy posed is fallacious, but I only mention this because you asked. Deltahedron (talk) 21:32, 19 August 2014 (UTC)

Deltahedron's aggressive stance on this matter notwithstanding, the state of mathematics rendering on Wikipedia is disgraceful. It has not meaningfully advanced in the years that I have been editing, despite massive improvements in the available pool of open source solutions. If Wikipedia is to continue to be used as a serious resource for people studying technical fields, improvement of the support for LaTeX needs to be made an immediate priority. The WMF's brush-off response is also unacceptable. Foundation representatives need to get their heads out of the sand and address this pronto. S?awomir Bia?y (talk) 20:46, 19 August 2014 (UTC)

@S?awomir Bia?y: Again, I disagree that everything is WMF's responsibility. Wikimedia's software needs are and have always been met by a collective of editors, developers and sysadmins, some paid, most volunteers. The WMF is not the communities' mother, and isn't and hasn't been solely responsible for much of the software you use daily; in many cases, it's almost entirely uninvolved.

Differing areas of the software have differing levels of staff vs. volunteer involvement. For instance, I believe that all of the maths-related technology you're currently disparaging as "disgraceful" was created by volunteers, not by paid developers, and almost all of it back in the early 2000s (and you're right, its age is showing, as is the case with much of the software for Wikimedia wikis). In the other direction, despite long term requests for a rich/visual editor starting in 2003, no volunteers felt ready to take on the task, so WMF has funded that from 2011 onwards (though volunteer coders have contributed significant amounts there too).

That said, I'd be keen to understand what in your view would be us "get[ting] [our] heads out of the sand". Jdforrester (WMF) (talk) 21:19, 19 August 2014 (UTC)

WMF decided to fund visual editor, a solution for a non-existent problem, but not proper LaTeX support, a problem that has been known about for ten years? Obviously the social media aspect of the encyclopedia is a bigger priority for the foundation than the encyclopedia aspect. So I guess we have our answer. Thanks. S?awomir Bia?y (talk) 21:29, 19 August 2014 (UTC)

Indeed, we did our best, we put up our best case, with the best support we could muster, and we were turned down. That is the answer. Mathematics development from now on depends on volunteers appearing from somewhere (the magic pixie solution, I believe someone called it) and the staff being able to spare the time to help them integrate any code they come up with. James believes this is a "strong future" and while I'm willing to look for a way forward, if someone can find it, I also think we need to consider whether the time has come. WMF projects are clearly at a major change point, the old ways are no longer viable, and the old guard may find themselves no longer part of that strong future the WMF have planned. Deltahedron (talk) 21:43, 19 August 2014 (UTC)

I think I'm being quite restrained, given that James has seen fit to accuse me of "misleading, to put it mildly", "you try to twist my words", "Your continued grossly bad faith responses" and has described this community's constructive proposals to WMF as "complaints" and "demands". However, I am still looking for a way forward, and if, as James thinks, mw:Extension:Math/Roadmap is the place to go then, then we shall just have to go there. Deltahedron (talk) 20:56, 19 August 2014 (UTC)

Indeed. I think I would be more blunt. Anyone giving you the run-around on this issue should be seriously worried about their possible future at the foundation. S?awomir Bia?y (talk) 21:09, 19 August 2014 (UTC)

I've read a couple of these threads, and I don't understand exactly what is happening. Is the worry that an upcoming visual editor will make math editing much less pleasant than the status quo? Or is the worry that Wikipedia's math support is stagnating, while the rest of the world progresses? In other words, are we worried about things getting worse, or just not getting better? Mgnbar (talk) 21:48, 19 August 2014 (UTC)

I am not normally a pessimist, but I expect WMF to begin actively driving out mathematics (and computer science, physics, and engineering) editors before too long. Our articles are a small fraction of Wikipedia, and unlike lists of Pokémon they require extensive development effort, effort that could go to shiny toys like WP:Flow and WP:VisualEditor. Removing mathematics support would vastly simplify their lives and still satisfy 99% of their audience, so I doubt if it will be long before it happens. Ozob (talk) 02:02, 20 August 2014 (UTC)

@Ozob: I have no intention of removing the existing mathematics support the community have worked so long to build. Worry not! Jdforrester (WMF) (talk) 02:11, 20 August 2014 (UTC)

But if a high-priority project is blocked because it would require months of work on mathematics rendering, are you really willing to fight back? Where would your engineers find time? Look at their schedules: can one of them carve out three months (longer, if you account for their other responsibilities)? I'm sure that WMF is willing to keep mathematics support as long as it doesn't conflict with other priorities, but years of experience have shown that it is clearly unwilling to do mathematics development. Furthermore, because mathematics support is complicated, few people in the community have the technical skills, time, and interest to volunteer to lead such a large project. Sure, it's conceivable; but if I were the one responsible for mathematics rendering, then, given the other demands I have on my time, deliverable code would take years. With no support in sight, the obvious conclusion is that some day, mathematics will disappear from Wikipedia.

Put more simply: WMF doesn't care. Ozob (talk) 04:19, 20 August 2014 (UTC)

We had something like this a year or so ago when it became clear that there were issues about interaction of mathematics markup, Visual Editor and Flow. I'm far from saying that WMF were deliberately trying to break mathematics editing, but it was clearly not a high priority, even after they were made aware of the issues. The mathematics component of VE was a GSOC student project: this is the best we may now reasonably expect -- not that it's removed, but that it simply ceases to function in newly released software because there is no plan to do continue it, no effort available to support it, and that it it survives, it's on the basis of ad hoc unplanned unsupported uncoordinated volunteer effort. That is the "strong future" we have to look forward to. Deltahedron (talk) 06:36, 20 August 2014 (UTC)

@Deltahedron: Just to be very clear, there was never even a remote possibility that VisualEditor or Flow would not support formulæ. There wasn't ever an "incompatibility"; such an issue existed purely in the minds of people raising the (understandable, if entirely misplaced) concern that something might not work. Repeating the unfounded claim now, however, and especially doing so whilst painting yourself into the position of heroically saving the wiki from the evil WMF who just doesn't listen unless you scream from the roof-tops, is just FUD (or I could use less charitable terms). Please don't let yourself be tricked into saying false things like this. Jdforrester (WMF) (talk) 18:08, 21 August 2014 (UTC)

My statement was "there were issues about interaction of mathematics markup, Visual Editor and Flow". Are you saying that is false? If you wish to use the word "false", quote an assertion of mine; it is a waste of your, my, and everyone else's time to make statements that no-one ever made and then proclaim them to be false. Here's an example. You said "there was never even a remote possibility that VisualEditor or Flow would not support formulæ" That is incorrect, and to show you that it is, I refer you to [43], where Brandon Harris says "I cannot promise that there will be mathematics markeup in normal discussion comments". In other words, there was a time, namely 23:42 on 17 August 2013, when a senior member of WMF staff expressed his view that mathematics markup would not work in normal Flow discussions. You also stated that there was "never an incompatibility". That is incrrect, and it was resolved by using Parsoid, but not without bugs: see Wikipedia_talk:Flow/Archive_6#Mathematics_markup. So on 19 October 2013 there was an incompatibility. Please review your comments in the light of the evidence, and then withdraw your words "unfounded" and "false". Deltahedron (talk) 18:29, 21 August 2014 (UTC)

Additional comment on the claim "there was never even a remote possibility that VisualEditor or Flow would not support formulæ". I just tried it again at mw:Talk:Sandbox and mathematics does not work under Flow, a year after the discussions I mentioned. Deltahedron (talk) 19:50, 29 August 2014 (UTC)

@Mgnbar: Deltahedron wrote a summary of the proposal here. Speaking for myself, there is an element of both concerns. It is a definite concern that adequate support for editing mathematics will be removed from VisualEditor, since inclusion seems to be rather an afterthought entirely dependent upon the valiant efforts of one or two volunteers. But at the end of the day, I don't really think that will happen; the blow-back would be Wikipedia's own doom. The other element is the solid lack of improvement. We have for years been screaming for proper mathjax support (as summarized as the first "Specific" point of Deltahedron's summary). But instead of funding this important but mundane feature, the WMF throws its resources into developing VisualEditor, Flow, and other questionable and unimportant bits of flashy gadgetry. This clearly demonstrates the perversity of WMF's engineering priorities. S?awomir Bia?y (talk) 11:43, 20 August 2014 (UTC)

It is important to remember that James is not in a position to be able to set the goals of the organisation. As such, he could not reassign engineers even if he wanted to. I would recommend following James's advice to contribute to the roadmap. Failing that, you could make your case directly to Erik Möller, the Vice President of Engineering and Product Development. --Dan Garry, Wikimedia Foundation (talk) 02:31, 20 August 2014 (UTC)

Dan, we know that, and did not ask or expect him to. If you follow the links in my first posting in this section, you'll see that we have already made our case, at Jimmy Wales's suggestion, and he passed it on to the Board and to Lila. The answer was, as I quoted above, "It's one of those things that is "on the radar" but for now I don't imagine that we would be able to put it on the roadmap for the foreseeable future". So your advice, though doubtless well-meant, is somewhat behind the curve. We tried every element of what you suggest, and it failed. The question we are discussing now is, how we can move forward to sustain mathematics rendering and editing in the absence of any material support or guidance from WMF. That may not be easy -- indeed, I believe it calls into question the sustainability of mathematics content in Wikipedia. Deltahedron (talk) 06:16, 20 August 2014 (UTC)

@S?awomir Bia?y: I'd read that summary. (Thanks anyway.) What I really needed to read were the linked Wikipedia:Visual Editor and Wikipedia:Flow articles. The former says that classic wikitext/LaTeX editing will be available. So things won't get worse than status quo? The latter is a new discussion system. Does it use Visual Editor? With or without the classic mode?

I still don't understand the basis for comments such as "it does not appear that mathematics has a future here" or "Is it time for mathematicians to leave Wikipedia?" (made by the same editor here). Mgnbar (talk) 15:20, 20 August 2014 (UTC)

Those comments were made at a time when there was definite reason to believe that mathematics markup would not be compatible with VE and Flow, or at least, that they might have to be edited in a different and less convenient way than ordinary text. (It is my private belief that the incompatibility had not been consciously recognised by VE/Flow developers until it was raised by WPM members, but that may be incorrect.) After some discussion, it became clear that that mathematics markup editing would be available in VE, because a mathematics component for VEwas written, as a student summer project (ie, not by WMF staff). Deltahedron (talk) 16:48, 20 August 2014 (UTC)

Although the current system of displaying equations in Wikipedia is marginally better than the output of an old-school latex2html script popular in the 1990s, it has not been substantially improved essentially from the very early days. This is in marked contrast to the rest of the internet, for which there are open source solutions that are a vast improvement over what we have here. Largely due to volunteer efforts of some developers, we now have a MathJax system that kind of works. There remain significant performance issues that need to be fixed. S?awomir Bia?y (talk) 15:49, 20 August 2014 (UTC)

(ec) Mgnbar, technically it sounds as though previous functionality will not be deliberately broken. However, what we have may be described as limping along: I have stopped using MathJax because it is horribly slow and frequently fails to render. I have tolerated the uncomfortable truce between PNG and HTML in articles in the expectation that this would be resolved in the not-too-distant future. Already, the LaTeX supported here requires a number of inventive workarounds using overlaying of symbols to create new symbols, or creating a mosaic of PNGs. Watching the WMF's responses, it is evident that I should now not expect any fixes, only a slow degradation as the remainder of WP becomes progressively more incompatible with the existing LaTeX support. The WMF's attitude comes across as "it's not my problem". It is already clear that several of the top mathematical WP contributors are taking umbrage to this attitude.

I'm with Deltahedron on this. If we can find a place where a group of people with mathematical and scientific interests can collaborate while actually feeling welcome, I'll be there like a shot. And if this perception is widespread enough, the comments you refer to might have relevance. --Quondum 16:10, 20 August 2014 (UTC)

There is the Wikipedia:Right to fork. The database for en.wikipedia articles currently stands at around 10Gb compressed, 44Gb uncompressed for the articles, according to Wikipedia:Database_download#English-language_Wikipedia. Articles in mathematics categories are currently about 1% of the total number of 4,585,263 articles, as far as I know (I don't have a reference to hand), so presumably about 1Gb compressed, 5 Gb uncompressed (in pther words, one memory stick). One possibility would be to ask Encyclopedia of Mathematics whether they could host the articles in some holding area and then transfer them into the EoM mainspace. Another would be to find someone with a server to spare... Deltahedron (talk) 17:13, 20 August 2014 (UTC)

Portal:Mathematics states 30,412 mathematics articles currently. So just under 1%. Deltahedron (talk) 20:50, 20 August 2014 (UTC)

I've just done a scan of and old database dump from March and then there were 34,809 articles with some latex mathematical formula in them. 27% had just one equation, 50% had 5 or fewer and 25% has 17 or more. The article with the most equations was Propositional calculus with 758 formula. The total number of equation is 545,870 in all mainspace articles.--Salix alba (talk): 19:02, 21 August 2014 (UTC)

The is not only the EoM as an already existing alternative but also PlanetMath and possible Citizendium, though personally I prefer Wikipedia to them so far for various reasons.--Kmhkmh (talk) 00:19, 22 August 2014 (UTC)

I just want to point out a small fact that EoM uses MediaWiki with mathjax. In other words, "in theory", it cannot have a better math rendering support than Wikipedia. To me, Deltahedron seems too pessimistic. For instance, not every math article needs to have formulae and thus latex, and at least things are not broken (yet). I do find the wanting on the part of the foundation, though. Why can't they just deliver what editors want instead of delivering what we didn't ask, the latest example being image viewer. What I want see is not the continuing display of drama (korean soap is enough for me) but just simple very reasonable technological upgrade that puts Wikipedia on par with other sites. -- Taku (talk) 18:16, 20 August 2014 (UTC)

I cannot say why WMF have decided not to "just deliver what editors want", but that they have chosen this path is undeniable. There's a very interesting personal posting by WMF Board chair Jan-Bart de Vreede here. He makes it clear that WMF projects are at a crossroads and that WMF Board has selected Lila to take the projects in a particular direction. Bullet points describing that new direction include:

I hear a lot from the few and the angry. There is an argument I hear a lot: "We are the community, without us the projects would be nothing. We are the ones who got us here." That is true, to a degree. But at the same time... we don't want to be here.... We want to be much further along the road.
We want to attract new editors. They don't have to become heavy editors, they could even contribute once in a while, as long as we get lots of them. We have to make it easy enough for anyone to contribute so that people once again feel that "anyone can edit."
We need to move faster than ever before. This means we need to be tolerant of things we may not like and let experimentation happen. We also need to remove things we are attached to that don't have wide adoption.
We need to act as one community, not 1,000. This means we cannot enact the wishes of a few hundred, but have to build processes that support the successes of millions.
All of this is going to require change, change that might not be acceptable to some of you. I hope that all of you will be a part of this next step in our evolution. But I understand that if you decide to take a wiki-break, that might be the way things have to be. Even so, you have to let the Foundation do its work and allow us all to take that next step when needed. I can only hope that your break is temporary, and that you will return when the time is right.

All of this sounds to me like a fair warning to those of us who have helped to build the encyclopaedia that unless we move in the WMF's chosen direction, which involves tolerating whatever the WMF decide we should have, we can and should leave; attracting new editors means shiny new editor experiences which may or may not support mathematics; somehow the "we cannot enact the wishes of a few hundred" (while I presume that it primarily refers to the various community votes against VE and MV) suggests that the (few and angry?) mathematics editors are going to carry even less weight, if possible, than before. So in view of this strategic overview, coupled with the WMF's rejection of the proposals submitted via Jimmy Wales, and the absence of any engagement between WMF staff and volunteer developers in mathematics, it seems not unreasonable to prepare for a graceful and productive exit as an option that may be inevitable in the not-too-distant future. Deltahedron (talk) 18:38, 20 August 2014 (UTC)

This story on the WMF's disinterest in maintaining a different important feature (the ability to find the source page of an image) is perhaps instructive about their attitude towards the preferences of existing editors and their ability to continue editing Wikipedia. --David Eppstein (talk) 19:14, 20 August 2014 (UTC)

Thanks for the link. (An analogous discussion on English Wikipedia is interesting.) When you say "find the source page", you mean the "File:..." page? I can get to it from the Media Viewer with one click. So that's two clicks total. It used to be one click. So getting to the "File:" page is less convenient than it used to be. On the other hand, it doesn't really affect my "ability to continue editing Wikipedia".

Similarly, the stated goals of Visual Editor and Flow seem noble and prudent for Wikipedia's future. (Whether the software fulfills those goals is another issue.) I've edited Wikipedia with PNGed LaTeX for 9 years. I can go another 5 years, unless it's clear that VE is going to break the PNGed LaTeX before then.

By the way, it's great that editors such as Deltahedron are engaging with the hierarchy, to make sure it stays aware of math typesetting issues. Mgnbar (talk) 03:46, 21 August 2014 (UTC)

Yes, you can get to it with one click, from a tiny little icon on the viewer display that their user studies demonstrated that users were unable to discover easily. But the link also mentions a proposed change to eliminate frames on images, and the "zoom" icon within the frame, which would make it impossible to get to the File: page for image maps (because clicking on the image itself would do something else). --David Eppstein (talk) 03:57, 21 August 2014 (UTC)

I've been following this on and off and have seen a lot of heated words but I can't see at all what over. I've seen no reports of problems with formulae and formula editing, or at least none that haven't been promptly and appropriately addressed. Nor are there changes on the horizon that will break formulae editing. Flow has been mentioned but that's months if not years from wide deployment. It cannot be judged now based on an early test version.

Formula support has been significantly enhanced in recent years. The addition off MathJax to MW is a welcome addition, and addressed the main complaint about the previous system, it's poor graphics quality. The Visual Editor's formula editor with live preview improves greatly on source editing. But though I don't have stats I suspect neither has replaced the previous system: editing source to generate PNGs still works, perfectly well for many if not most editors. It's not as if there was or is some pressing problem that needs addressing. There are things it would be nice to have, such as an entirely visual formula editor, but this cannot be a high priority as it would be a lot of work, nothing's broken now, and maths is only a small part of the encyclopaedia.--JohnBlackburne^words_deeds 19:23, 21 August 2014 (UTC)

If I'm not mistaken is PNG rendering still the default setting and still looks ugly and out of place when used within text. Although Mathjax might work great for some, it is still experimental and afaik not without issues. Insufficient math/latex support of VE and Flow is imho a big issue as well, at least when they become implemented as default options. A system for talk pages of math/sciences/engineering articles that has no proper latex support is imho a no-go, then I rather use the current talk page as it is.

More generally speaking I'm getting more and more the impression that the WMF develops a lot of software that large parts of the community don't want or don't care for while important requests from the community seem to be put on the back burner. In addition board member statements like this one(m:User_talk:LilaTretikov#Our_Future_and_the_role_of_the_Foundation) make you wonder, whether they have their priorities and the project goals straight. They seem to primarily measure Wikipedia's success in terms of traffic rankings, in comparison to commercial internet companies and fancy guis. Such a mindset loses sight of the fact that Wikipedia is primarily about free encyclopedic high quality content and the success should be measured by the degree to which this is achieved. Traffic rankings are merely a proxy to assess that (high quality presumably leads to high traffic) and a particular stylish or fancy interface is at best an afterthought here. The notion that a state of the art gui will bring us much needed new editors willing to provide man hours and quality work seems a bit of a pipe dream and given that WMF is increasingly pissing off its current editors providing the core content is actually almost a bad joke.--Kmhkmh (talk) 22:12, 21 August 2014 (UTC)

The VE maths editor has improved since I last looked. They have addressed the problem with the edit box obscuring the equation, now it always appears just below the displayed equation. The box for the equation is a bigger, it does still require some scrolling for the more complicated expressions. Whilst it does not respect my preference for MathJax while editing, always using PNG mode, it does now gracefully go back to displaying MathJax after saving. An annoyance is that if while editing an equation there is a temporary syntax error (say if your start a \begin{align} but have not yet added the closing \end{align}) the displayed equation will show a red "failed to parse" message. This can cause the page to jump about a lot flipping between a good display and the red error message.--Salix alba (talk): 22:29, 21 August 2014 (UTC)

@Salix alba: For what it's worth, one of the team in their spare time proposed a change in May to show MathJax rather than PNGs for formulæ in VisualEditor, and editing to MathJax rather than server-provided PNGs, but it needs some work. Jdforrester (WMF) (talk) 23:14, 21 August 2014 (UTC)

Just posting to note my agreement with JohnBlackburne. --JBL (talk) 01:43, 22 August 2014 (UTC)

Despite my earlier statements in this thread, I feel compelled to defend WMF a little here. You and I may be comfortable with wikitext and with how discussion on WP is done, but many people--most especially potential new editors--aren't. I've lost count of the number of times I've seen IP editors start a badly formatted thread in the middle of a talk page. They don't do it on purpose; but they don't know how to edit, and they don't know how talk pages work, and they make good faith mistakes. I am absolutely certain that there have been many others who made it to the talk page but gave up without editing because they were overwhelmed and intimidated. Talk pages are an ad hoc collection of conventions structured around tools meant for editing articles. They are--completely objectively--terrible.

That doesn't mean that I think that VE and Flow are good ideas or will be a success, and I'm not convinced that they're a good use of development resources. But I'm also willing to accept that the Foundation might be right to try. They've invested a lot more time thinking about this than I have (I prefer to think about math), and maybe I would come to the same conclusions as them if I had spent that much time thinking about these problems.

What I worry about is what WMF will do about support for less mainstream features. That includes not only mathematics (my biggest personal concern) but also features like those that Jdforrester mentioned above (e.g., music and hieroglyphics). I am not convinced that WMF is in a position to accurately evaluate the needs of the editors who work on specialist topics, and I'm still convinced that WMF doesn't care about us. Ozob (talk) 01:45, 22 August 2014 (UTC)

I should note that MathJAX in Wikipedia (besides being opt-in) uses client-side rendering which is pretty slow in practice, something that is well known: https://www.mediawiki.org/wiki/Extension:Math#Discussion_of_pros_and_cons JMP EAX (talk) 00:19, 22 August 2014 (UTC)

Why are we not doing server-side rendering? -- Taku (talk) 22:02, 22 August 2014 (UTC)

Server-side rendering is, as I understand it, the plan for the future that Physikerwelt is working on. From m:Extension:Math: "Beginning from Math 1.2 // MW 1.23+ you can use a Mathoid server that uses MathJax to convert texvc input on the server side to MathML+SVG rendering. Mathoid is the rendering mode that is going to be used on future Wikipedia." -- Jitse Niesen (talk) 15:00, 23 August 2014 (UTC)

Looking at MathJax Output formats the SVG mode is only supported by IE >=9 not all andriod devices support it. Its also limited in the character is can display so some obscure character might not work. MathML mode only works as standard on firefox and with a pluging on IE. So both server-side options will have some holes in support. The other problem with server-side is that it can't always respond well to client side changes, such as changing the page width, zooming or using different locl font size. Server-side rendering will work for a lot of people but it not the perfect solution, for that we will have to wait until the other browsers all adopt MathML (which is taking a little longer that waiting for the WMF).--Salix alba (talk): 20:32, 24 August 2014 (UTC)

For anyone interested in community participation in software development across all wiki projects, a discussion has been started at m:Community Engagement (Product)/Process ideas. Deltahedron (talk) 19:28, 22 August 2014 (UTC)

Math 2.0 is now live in betlabs. [44] Thanks to User:Jdforrester (WMF) for the support. --Physikerwelt (talk) 21:29, 22 August 2014 (UTC)
- Page takes forever to load in Google Chrome, i.e. nothing gets really displayed. JMP EAX (talk) 16:54, 23 August 2014 (UTC)

Same for me in FF 31.0. Deltahedron (talk) 17:12, 23 August 2014 (UTC)

- Page is loading fine for me (FF 31/win8.1). However, first test page with MathML enabled [45] produced "(Failed to parse (MathML with SVG fallback (experimental): Invalid response ("Error fetching URL: couldn't connect to host...") from server "http://localhost:10042":)" error messages instead of equations.TR 11:49, 25 August 2014 (UTC)
- The beta labs server seems to be working fine now and does give me MathML. -- Jitse Niesen (talk) 13:55, 30 August 2014 (UTC)

dvisvgm

I have used this to covert some tikz stuff I made to SVG (though noting for Wikipedia yet.) It seems it can also convert equations to SVG via htlatex at least, but that requires some htlatex hackery/config: [46]. Beware that unlike dvipng, dvisvgm needs ghostscript to actually work (at least with tikz; that's because it relies on gs as interpreter for PS/PDF DVI specials. There's a direct SVG driver in tikz that can--in theory--produce SVG directly, but it has some major bugs. Also, that driver probably won't help with equations, which tikz itself doesn't handle.) JMP EAX (talk) 22:06, 24 August 2014 (UTC)

There are some production-quality SVG TeX backends like BaKoMa (which can even produce a bit of SVG+SMIL, i.e. declaratively animated SVGs), but they are all commercial. The htlatex/dvisvgm hackery seems the only free one, besides MathJax, which is honestly even more silly on the server side (via Mathoid) as it basically runs a fully fledged web browser process to render stuff and MathJax re-implements TeX in Javascript (and not terribly well). JMP EAX (talk) 22:10, 24 August 2014 (UTC)

mini-rant about MathJax

For some backgrond info: MathJax was basically made by Design Science (company), the makers of MathType. Before you think that's awesome, MathType was the tech behind the equation editor before Office 2007. M$ ripped out that (or rather made it legacy) after they implemented their own editor which uses the new OpenType Math fonts (and standard) that M$ designed inhouse [47], which is way, way better, coming close to TeX quality. Now MathType (Design Science) was probably going to go the Y&Y way [of the dodo] after that, but they managed to reinvent themselves as a web services company. Their actual tech is quite meeeeh, but it's the only free web thingy for math basically, given that browsers have started to drop [direct] support for MathML last year. MathJax is basically a ghetto monopoly now. JMP EAX (talk) 22:34, 24 August 2014 (UTC)

MathJax does not use actual OpenType Math font features (i.e. the superset of TeX math font metrics that M$ put into OpenType Math and recently into the ISO standard thereof). MathJax uses the STIX fonts, which themselves don't yet have that. Most glyph positioning is done by hackery in MathJax. The XITS fork of STIX (and Asana Math) have actual OpenType Math support in the free fonts world. JMP EAX (talk) 22:48, 24 August 2014 (UTC)

FYI, here's the WMF-ish plan: [48]. JMP EAX (talk) 05:06, 25 August 2014 (UTC)

And just so you don't think I'm just gratuitously ranting about this, I've attached a sample problem with MathJax rendering in Google Chrome, where MathJax actually has to do some rendering/positioning (as opposed to just translating a subset of LaTeX to MathML, which is what it does in Firefox.) It's not an optical illusion, the enlarged version also has baseline alignment problems between sub-parts of the aa^-1 formula. JMP EAX (talk) 07:11, 28 August 2014 (UTC)

So, what do you suggest for us? It's all very well to rant about MathJax, but without alternative suggestions that won't improve matters. From your description, it looks like it will be a lot of effort to get the dvisvgm route to work and it is not clear that it will be better. -- Jitse Niesen (talk) 08:26, 28 August 2014 (UTC)

No one has an illusion that there is a perfect solution. Given that the web doesn't support math natively (mathml was once promising but isn't getting anywhere), there will remain some degree of hackery in a foreseeable future. What we're is asking some "modest" performance and appearance improvement that puts Wikipedia "on par" with other sites. This is a feasible cheap goal. By the way, although Deltahedron likes to frame this in a math-editing issue, this is actually a larger issue: Wikipedia as a website looks old. For example, the main page is another part of Wikipedia that has remained unchanged for "ages". WMF clearly understands this and that's why they are trying to put stuff like VE and media viewer to modernize the website Wikipedia. (Ah, this reads like a rant.) -- Taku (talk) 12:27, 28 August 2014 (UTC)

But Deltahedron did hit a nail in the sense that the fundamental problem is no one, as it seems, is accountable for math rendering; that is, it would be nice if there is some math-tech guy who fixes the math implementation here whenever it breaks and also plans to a further development (not someone "oh, I don't know it's not part of my job description.) -- Taku (talk) 12:39, 28 August 2014 (UTC)

Since you guys are probably (directly or indirectly) paying AMS dues, it might make some sense to try talk to whoever is paying for MathJax at AMS to convince them that money is better spent on native MathML support in browsers. None of the MathML implementers (in any browser [engine]) got paid anything for their MathML implementation work. Instead AMS decide to sink money a polyfill (MathJax) that will always suck in the long run. But given the disaster that the STIX fonts were, I'm not terribly surprised AMS made another bad engineering decision... JMP EAX (talk) 13:05, 28 August 2014 (UTC)

You think Microsoft will implement MathML support for some cash? And then a decade later we can finally enjoy MathML in the majority of common browser versions? ;) --Unverbluemt (talk) 12:02, 31 August 2014 (UTC)

FWIW, I've asked someone I know (former prof of mine) who is family closely associated with the inner circle of ACM SIGACT and they don't have funds for something like this, nor do they see it as much within their remit. JMP EAX (talk) 18:26, 28 August 2014 (UTC)

I am not a member of the AMS, but will explore this within the UK community. Email me if interested, as this is clearly no longer a WP or even WMF issue. Deltahedron (talk) 18:33, 29 August 2014 (UTC)

Alignment of PNGs with text

The following might be of interest http://tex.stackexchange.com/questions/44486/pixel-perfect-vertical-alignment-of-image-rendered-tex-snippets JMP EAX (talk) 02:28, 25 August 2014 (UTC)

MathJax and texvc don't support the same subset of LaTeX

I just realized this when I kept seeing the flashing "failed to parse [blah, blah]". Turning MathJax off makes that error permanent. Basically MathJax supports \mkern (a fundamental TeX command) but texvc chokes on it. JMP EAX (talk) 17:00, 28 August 2014 (UTC)

I believe the current plans are to run all equations through texvc first. Basically this means the subset of LaTeX wikipedia maths supports is defined as those parts supported by texvc. There are a few other incompatibilities documented at Help:Formula#Unimplemented elements and workarounds.--Salix alba (talk): 17:17, 28 August 2014 (UTC)

Maltsev or Mal'cev or Malcev varieties or conditions

Do we really not have page for these? I tried various permutations, but I still can't find them on wiki. Nor are they mentioned in Anatoly Maltsev. JMP EAX (talk) 15:58, 31 August 2014 (UTC)

There is a brief mention in Group extension#Central extension and we have Malcev algebra and Malcev-admissible algebra, but I could find nothing else. If you would like to create an article for Malcev variety, go for it! --Mark viking (talk) 16:34, 31 August 2014 (UTC)

Sep 2014

?=2? in the FAQ

I never heard of this. Is it even something worth including in the FAQ? JMP EAX (talk) 22:40, 3 September 2014 (UTC)

Search this page's archives for tau and you will see many discussions over the years. After doing so, perhaps you will become a Tauist. --Mark viking (talk) 22:52, 3 September 2014 (UTC)

I see. By the way, there's an article that has been stuck in draftland for a couple of years: Draft:Tau (Proposed mathematical constant). JMP EAX (talk) 00:50, 6 September 2014 (UTC)

Discussion notification

I have posted a request to change the URL for Zentralblatt MATH linked to from WP templates and modules from HTTP to HTTPS. Please feel free to comment there. It Is Me Here ^{t / c} 16:03, 9 September 2014 (UTC)

Edward Nelson dead?

An anonymous editor has edited Edward Nelson to claim that he is no longer with us. I am very sorry to hear this, if true -- he was my favorite ultrafinitist, by a lot. I corresponded with him briefly at one point while I was in grad school. Can anyone confirm or refute? --Trovatore (talk) 01:49, 11 September 2014 (UTC)

http://www.math.princeton.edu/news/home-page/professor-emeritus-edward-nelson-passed-away-september-10th. PrimeHunter (talk) 02:33, 11 September 2014 (UTC)

Taylor series in several variables section

First formula - shouldn't there be a factorial of the sum of indexes instead of the product of factorials of all indexes? -- Preceding unsigned comment added by 78.104.183.88 (talk) 11:48, 11 September 2014 (UTC)

See Talk:Taylor series#Multi-index notation. S?awomir Bia?y (talk) 12:06, 11 September 2014 (UTC)

To 78.104.183.88: No. When differentiating with respect to one variable, the others are held constant. So only the exponent of the one variable is brought down and needs to be cancelled out. JRSpriggs (talk) 12:29, 11 September 2014 (UTC)

List of mathematical shapes

ALERT, List of mathematical shapes (edit | talk | history | protect | delete | links | watch | logs | views) has been greatly expanded by 300kB this month, by users occupying IP ranges 99.xxx.xxx.xxx and 108.xxx.xxx.xxx who have also been reverting each other. Some of the new additions are not mathematical shapes at all, and a proposal to rename the page exists at talk:List of mathematical shapes. Up until this rash of activity it was only 2.5kB large -- 70.51.46.146 (talk) 05:18, 21 September 2014 (UTC)

Problem at Ramsey theory

Could use more eyes at Ramsey theory. An editor has been putting in unpublished (look carefully at the references) new results and has been reverted three times now. Bill Cherowitzo (talk) 04:03, 23 September 2014 (UTC)

You mean Ramsey's theorem. I have applied temporary semiprotection to encourage the IP and the new editor to work for consensus. So far nobody has used the article talk page. EdJohnston (talk) 04:13, 23 September 2014 (UTC)

Suren Arakelov

Can anyone point to a reliable source for his biographical details? In particular, is there any support for the assertion that he is of Armenian descent? The article currently has no references that give anything about him personally, as opposed to Arakelov theory, and if nothing emerges then the article may have to be deleted on BLP and general notability grounds. Deltahedron (talk) 15:28, 28 September 2014 (UTC)

Interesting case. This compilation of information about people whose names are embedded in Math Subject Classifcation has a good bit of information about him distributed through the document. It was compiled by Dave Rusin. It looks to have good information, but isn't a peer-reviewed document. --Mark viking (talk) 18:37, 28 September 2014 (UTC)

I saw that too, it's linked from the Russian-language version. I can't see that being a reliable source: it's effectively a personal blog quoting personal emails. I'm certainly not going to include assertions of mental illness based on that. Deltahedron (talk) 18:54, 28 September 2014 (UTC)

Unsourced material at Midy's theorem

Somebody restored unsourced material at Midy's theorem here: https://en.wikipedia.org/w/index.php?title=Midy%27s_theorem&oldid=prev&diff=626394495 on the grounds that "this is referred to in other places in article". More precisely, the material derives from an unpublished 2005 article in a pdf at a personal homepage. If this has been published in the meantime by all means we can use this, but otherwise it seems more reasonable to remove these mentions "in other places in article". Tkuvho (talk) 10:22, 21 September 2014 (UTC)

This reference [49] may be helpful. Deltahedron (talk) 10:46, 21 September 2014 (UTC)

This published article by Ross is certainly a fine source if it proves the relevant generalization of Midy's theorem. Why should the page rely on an unpublished pdf from a homepage rather than a published article by Ross? Tkuvho (talk) 11:08, 21 September 2014 (UTC)

I restored the section headed "Extended Midy's theorem" because it had been excised without considering the rest of the article. As a result, the following section, which starts "Midy's theorem and its extension ...", could have left the casual reader baflled as to what the "extension" part refered to. There are further references to the extended theorem in the "Proof" section of the article. If we now have a better source for the extension, then certainly go ahead and add it to the article (I can only see a preview of the Ross article on JSTOR, so I am not clear whether this covers the extended theorem or not). Gandalf61 (talk) 14:23, 29 September 2014 (UTC)

Oct 2014

Category:Pretzel knots and links

Category:Pretzel knots and links, which is within the scope of this WikiProject, has been nominated for renaming to Category:Pretzel knots and links (mathematics). If you would like to participate in the discussion, you are invited to add your comments at the category's entry on the Categories for discussion page. Thank you. RevelationDirect (talk) 02:36, 1 October 2014 (UTC)

Comment on the WikiProject X proposal

Hello there! As you may already know, most WikiProjects here on Wikipedia struggle to stay active after they've been founded. I believe there is a lot of potential for WikiProjects to facilitate collaboration across subject areas, so I have submitted a grant proposal with the Wikimedia Foundation for the "WikiProject X" project. WikiProject X will study what makes WikiProjects succeed in retaining editors and then design a prototype WikiProject system that will recruit contributors to WikiProjects and help them run effectively. Please review the proposal here and leave feedback. If you have any questions, you can ask on the proposal page or leave a message on my talk page. Thank you for your time! Harej (talk) 15:17, 1 October 2014 (UTC)

Combinatorics terminology

Hi, I am sitting over a text that has the following passage: "The oligonucleotide spectrum owes much of its discriminatory power to the number of possible oligonucleotides: if n is the size of the vocabulary and w is oligonucleotide size, the number of possible distinct oligonucleotides is n^w; for example, there are 4⁵=1024 possible pentanucleotides." I would like to link it to the appropriate English Wikipedia article but am not sure which one this would be. On the German Wikipedia, the relevant information is in Variation (Kombinatorik), and that article links to Partial permutation here, which seems a plausible English equivalent to me, yet the article is written in a way that I am not sure it actually covers the same subject as the German one. Any pointers or clarifications? -- Daniel Mietchen (talk) 23:20, 2 October 2014 (UTC)

Partial permutation is, in the German terminology, a variation without repetitions. You want variations with repetitions, a different concept. I think the relevant article is n-tuple. --David Eppstein (talk) 23:34, 2 October 2014 (UTC)

Essentially what you have is exponentiation. This section of the article talks about elements from an alphabet Exponentiation#Combinatorial_interpretation. Maximilianklein (talk) 00:14, 3 October 2014 (UTC)

Thanks to both of you for checking. I'm going for Exponentiation#Combinatorial_interpretation. -- Daniel Mietchen (talk) 00:38, 3 October 2014 (UTC)

I believe that you have made the correct choice based on the content of these articles. However, the natural combinatorial term would be "n-tuple". The problem here is that n-tuple redirects to tuple where the concept gets confounded with a different usage (in computer science mostly) and gets buried in an attempt to encompass all meanings of tuple. I actually like the "variation with repetition" terminology used in German, but unfortunately that is not commonly used in English. I will attempt to add something to tuple that supports the n-tuple redirect. Bill Cherowitzo (talk) 04:03, 3 October 2014 (UTC)

Done Bill Cherowitzo (talk) 21:07, 3 October 2014 (UTC)

Wikipedia talk:Articles for creation/Geometric nonlinear finite element analysis

Dear mathematicians: This old AfC submission needs a lead and some rewriting, but is this a notable topic, and should the page be kept and improved instead of being deleted as a stale draft? --Anne Delong (talk) 14:26, 3 October 2014 (UTC)

Delete. The topic is already better covered by Finite element method and related articles, and this stub adds nothing of interest. --Quondum 19:20, 3 October 2014 (UTC)

I'd keep it. I agree this is a notable topic. Perhaps I am missing something, but nonlinear finite elements aren't covered Finite element method, as far as I can tell. We do have a good Wikiversity course on Nonlinear finite elements, which suggests that there is plenty of material out there upon which to base an article. This article only seems to cover geometric nonlinearities; there are material nonlinearities and boundary nonlinearities as well. --Mark viking (talk) 21:04, 3 October 2014 (UTC)

Well, if nonlinear finite elements aren't covered, the material could be added so that it is covered, or it could be its own topic, with a link to it from the other article. This is assuming that Quondum doesn't point out where it's already covered. If it's to be a separate topic, someone will have to write a lead summary for it (my math is too rusty). --Anne Delong (talk) 21:24, 3 October 2014 (UTC)

Beurling vs Beurling-Ahlfors transforms

The link Beurling transform redirects to Singular integral operators of convolution type#Beurling transform while Beurling-Ahlfors transform redirects to Grunsky matrix#Beurling transform. My understanding is that these are essentiually the same thing. What is the appropriate target? Deltahedron (talk) 18:56, 3 October 2014 (UTC)

I agree that the two redirects seem to refer to the same transform. Singular integral operators of convolution type#Beurling transform is a bogus target; it looks like it should be Singular integral operators of convolution type#Beurling transform in the complex plane. Given that the section Grunsky matrix#Beurling transform refers to Singular integral operators of convolution type as the main article, it seems reasonable to have both Beurling transform and Beurling-Ahlfors transform redirect to Singular integral operators of convolution type#Beurling transform in the complex plane.. --Mark viking (talk) 21:16, 3 October 2014 (UTC)

They are the same according to Hamilton, D.H. (2002). "Area distortion of quasiconformal mappings". In Kühnau, R. Handbook of complex analysis: geometric function theory. Volume 1. Amsterdam: North Holland. p. 158. ISBN 0-444-82845-1. Zbl 1074.30016. . Deltahedron (talk) 21:27, 3 October 2014 (UTC)

Redirect Radical extension

For the past three years, the redirect Radical extension has been targeted at Separable extension, but an IP editor has recently objected to this, on the grounds that the "redirect is nonsensical. Radical extensions are neither identical to nor special cases of separable extensions nor are they mentioned anywhere on that page."[50] Now, I know little of Galois theory, so I thought I'd ask for input here as to whether a more suitable target (or targets) is available, or whether the original should be restored. Thank you, VeryCrocker (talk) 20:45, 30 September 2014 (UTC)

Abelian extension (the redirect target of Solvable extension) sounds like a better choice to me for a redirect from radical extension. (Or we could have separate articles but these are all very closely related.) --David Eppstein (talk) 20:58, 30 September 2014 (UTC)

Or Abel-Ruffini theorem? Deltahedron (talk) 20:58, 30 September 2014 (UTC)

Are Glossary_of_commutative_algebra#R or Purely inseparable extension not potential candidates? I only ask because they mention the term. If more than one target is suitable, a disambiguation page could be made. --VeryCrocker (talk) 20:02, 3 October 2014 (UTC)

I don't think the term "radical extension" is ambiguous -- it's a subextension of a solvable extension, which is in turn an extension that can be factored into a tower of abelian extensions. But maybe since there are several relevant articles to link to, a stub that links to all of them would be appropriate. --David Eppstein (talk) 20:29, 3 October 2014 (UTC)

IMO, "radical extension" deserves to be a true article, because of the "fundamental theorem of Galois theory of equations" (the name is mine): If a field K of characteristic different of n contains the n-th roots of unity, an extension of degree n of K has a cyclic Galois group if and only it is a radical extension. This is this theorem that implies that a polynomial equation is solvable in radicals if and only if its Galois group is solvable. I'll try to write this article. D.Lazard (talk) 08:41, 4 October 2014 (UTC)

A good place to start might be a few lines at Glossary_of_field_theory#Field_extensions. Deltahedron (talk) 10:36, 4 October 2014 (UTC)

Modular exponentiation

We have long-standing articles at Modular exponentiation and exponentiation by squaring. (They should probably be merged, but that's not what I'm here to talk about.) Recently, a new editor has written a third article, Discrete exponential function, that covers much of the same material. He has rather persistently linked to it from other articles, such as Discrete logarithm. I have proposed a merge, but the editor refuses to respond to any kind of discussion. So we could use some input from the community in this little knot of articles. Mgnbar (talk) 21:33, 4 October 2014 (UTC)

The article had no content beyond what's already in modular exponentiation, so I changed it to a redirect. Ozob (talk) 14:57, 5 October 2014 (UTC)

Spinors

I have been attempting for some time to make the lead of the spinor article accessible to a wider audience, in part on my own impetus, but in part on the helpful urgings of others of varying skill levels. But now we seem to be at an impasse that would benefit from some outside input. Four milestones in the recent bout of edits are:

August 14 revision
This revision from yesterday, which was the culmination of I think the most input from other editors.
This revision from today, where I tried to get some "high brow" content into the first paragraph.
Finally, this is me giving up, and basically going back to the philosophy adopted by the August 14 revision, modulo saying things in hopefully a way that doesn't require the reader to know what an "irreducible representation" is, which I think is far beyond what likely readers of the article are already familiar with.

I would like some input on a way forward. It has already been suggested that the way forward is backwards, but I would find it hard to believe that all of the work and discussion in the mean time has been for naught. S?awomir Bia?y (talk) 12:48, 28 September 2014 (UTC)

There is now also this revision, thanks to helpful edits from User:RogierBrussee. I would appreciate any input from project members. S?awomir Bia?y (talk) 11:54, 29 September 2014 (UTC)

I have made a few further changes here. Someone else really needs to look at this the editing environment there has become problematic. One editor, who has accused me of ownership there (although it rather looks the other way around) is now threatening to revert to his preferred revision. The editor threatening to revert has run roughshod over rather a lot of discussion that has taken place, and not really correctly understood the sequence of edits that took place as the product of those discussions. I would happily welcome more constructive input, but this post seems to indicate no interest in constructive discussion. More opinions are urgently needed there. S?awomir Bia?y (talk) 18:06, 29 September 2014 (UTC)

To update, RogierBrussee has reverted to one of S?awomir's versions. M??c²???_?lk 20:54, 29 September 2014 (UTC)

Well, I think this revert leaves the lead in worse shape. Does anyone disagree? S?awomir Bia?y (talk) 20:55, 29 September 2014 (UTC)

I hate to say this, but it is not as good as this version you wrote, long before the "introduction" section was added. Based on the comments at talk:spinor not everyone is happy with it though... M??c²???_?lk 21:05, 29 September 2014 (UTC)

I reverted to one edit after my last edit which was indeed an improvement. After that things got worse than what they were in my opinion. More to the point I had asked Slawomir to back off after he spent days improving things without getting to a satisfactory result and let me have a go at it to which he agreed, and I would let it be known that I was finished. I object to Slawomir taking of on a new editing spree just hours after my first edits and before I said I was finished. I wrote that i would revert his edits and I did. After that I moved the two more technical paragraphs to the overview section and deleted what was there. In my opinion that is an improvement. Slawomir obviously disagrees and reverted everything. There seems to be this mistaken idea that spinors are just like vectors and one just has to use some magic explanatory tool like the non simply connectedness of the Rotation group. That is just not true. Root systems or Clifford algebra's will get you the existence of spinor representations, and with a lot of explanation you can relate that to representation theory but it is just not trivial. Therefore it is pointless to try to explain things for the laymen. I am all in favour making things as simple as possible but not simpler. For example saying that the Clifford algebra is generated by the gamma matrices misses the point, because what you have to do is to construct a representation of the abstract Clifford algebra (which is constructed from the vector space) to a concrete matrix algebra. So every choice of orthonormal basis and every choice of gamma matrices gives a different, albeit isomorphic representation of the Clifford algebra and a different but isomorphic representation of the Spin group. See? Seems like a trivial difference at first but now start reading Weinbergs (otherwise excelent) book on quantum field and notice how he starts writing down explicit gamma matrices on page 3 or so, which is horrible because now what depends on the choice of gamma matrices and what does not. The worst thing about this whole affair is that all this energy would be better spent on other sections. I particularly hate the example section which seems to be written by someone from geometric algebra people that want every thing inside the Clifford algebra. It would be so much better if the different constructions were run through and compared in dimension 3 and 4 (and perhaps dimension 2). RogierBrussee (talk) 23:00, 29 September 2014 (UTC)

+----------------------------------------------------------------------------------------------------+ "Therefore it is pointless to try to explain things for the laymen." This is an absolutely wrong starting position in editing an article that is likely to be read by probably many high school and college students, who are "laymen" by the standards of the revisions you have in mind. The lead must at least convey a sense of what the thing is about to all of the likely readers of the article. To disregard this consideration is astonishing. S?awomir Bia?y (talk) 23:10, 29 September 2014 (UTC)

Yes, I agree. This flies in the face of WP:TECHNICAL. We should strive to keep the leads of our articles at as low a level of difficulty as possible, while retaining the details of the subject later in the articles. Writing an article that can be read only by people who are already experts is pointless. --David Eppstein (talk) 23:55, 29 September 2014 (UTC)

See my lengthy explanation on laymen in the Talk page.

TL;DR Given that many of the mathematically and physically literate people here are already somewhat confused on the details about this subject (really nobodies fault I hasten to say, the confusion is widely taught), clarity and correctness take precedence over intuitive understanding because _there is no intuitive route to the existence of spinors_ , at least not one that I and apparently Michael Atiyah is aware of. The properties of spinors are easy enough to explain for say first year physics students, and I did, I think. In my opinion it is OK if even a bright high school student comes to the conclusion that they have something to do with the geometry of vectors and quantum mechanics, but for a proper understanding he or she needs more background. That is just the way it is, and no mention of WP:Technical can change that. Anyway I am tired of fighting this. It is not that I don't want to cooperate, I just cannot do it when every time I make an edit it is reverted within minutes or "improved" before I have time to get to a new round of editing. I have tried giving Slawomir input which he did try to incorporate at some point but only after a very long and frustrating process for all of us and with a result that nobody was pleased with. I have work, wife and kids and they all need attention. RogierBrussee (talk) 10:43, 30 September 2014 (UTC)

The bottom line here is that you seem to be of the opinion that your revision of the lead and introduction to the article is better than the current one. The community already responded quite positively to the initial edits aimed at making the lead accessible to a wider audience. The present version is the product of many revisions in response to comments on the talk page. Notwithstanding your current frustration, I think the current revision is superior than any that has preceded it, in large part due to your own efforts. But it is there for all to see, and I think others should be allowed to judge.

"For a proper understanding, one needs more background" -- yes, but so what? That does not mean we shouldn't try to explain things as best as we can to those that don't have this background. Surely that is one of the most important functions of an encyclopedia. Also, for a sufficient definition of "proper", this is surely an unreasonable attainment to expect of any reader of an encyclopedia article about spinors. Entire books are written about spinors. And even Sir Michael Atiyah, as you have helpfully pointed out, admits to not understanding them "properly". S?awomir Bia?y (talk) 11:57, 30 September 2014 (UTC)

I just want to say that despite all the frustration, head-butting and occasional drama, real strides have been made in this article. Comparing the August 11 version to the current version, both the lead and introduction are much, much improved in clarity and accessibility. I know there are still issues to hash out, but good job, you all. --Mark viking (talk) 20:28, 1 October 2014 (UTC)

Thank you RogierBrussee and S?awomir Bia?y (in no particular order) for the good work on the spinor article, and thank you for listening to every single concern from us mere mortals in the spinor world. YohanN7 (talk) 22:39, 3 October 2014 (UTC)

The recent edits have been a big step backwards in readability. I have more or less reverted these to the earlier revision, modulo minor copy editing, that met with favorable reviews as per above, pending discussion. My reasons have been articulated in detail at Talk:Spinor#New edits. Outside opinions would be helpful. S?awomir Bia?y (talk) 05:38, 6 October 2014 (UTC)

Scott domain unsourced

Looks like Scott domain has remained unsourced since 2009. I do see some real textbooks in books.google.com that could be used as sources, but if anyone happens to know a bit about this discipline's literature, they would probably do a better job than me picking random sources. Any takers? Rschwieb (talk) 13:10, 6 October 2014 (UTC)

Article for deletion Concave hull

Discussion at Wikipedia:Articles for deletion/Concave hull. -- D.Lazard (talk) 07:03, 10 October 2014 (UTC)

Wikipedia talk:Articles for creation/Linear Threshold Unit

Dear mathematicians: This old AfC submission is about an interesting topic and there appear to be plenty of references. I added some, but being unfamiliar with the topic I may have messed it up. Can someone please check this over, and also tell me if this is a notable topic that should be kept and improved? Or is it covered somewhere else under another title? --Anne Delong (talk) 18:56, 7 October 2014 (UTC)

It is possibly notable. An LTU is a historical name for a kind of artificial neuron proposed by McCulloch and Pitts and is also a simple kind of perceptron. My recommendation is to merge and redirect to the Artificial neuron#History section, where LTUs are already mentioned and where a reader can get a better context. If there are no objections, I can do this. --Mark viking (talk) 19:24, 7 October 2014 (UTC)

Go right ahead, Mark viking. I'm sure that you can do a better job than I. Please remember to credit Justprajwal, who created the draft, in your edit summary. Let me know when you are done, so I can move, redirect and attribute the old draft. --Anne Delong (talk) 20:52, 7 October 2014 (UTC)

The selective merge has been done at this diff. Please check that I did it correctly. Thanks, --Mark viking (talk) 22:09, 7 October 2014 (UTC)

Great. The draft is now a redirect at Linear threshold unit. --Anne Delong (talk) 12:03, 10 October 2014 (UTC)

Image of calculator deleted from Baker percentage article

My apologies if this question is not of interest to this group. I had placed an image of a calculator in the baker percentage article, since they're commonly used with baker's percentages, but it was reversed in this edit. Daniel Wing & Alan Scott say in The Bread Builders: Hearth Loaves and Masonry Ovens (page 8 & 9), emphasis added by me,

Since I placed the image, I obviously like it, and you just read a quote from a popular artisan baking book for it's use. What do you math folks think, is the calculator image appropriate in the article? Gzuufy (talk) 04:15, 16 October 2014 (UTC)

I agree with A bit iffy (talk · contribs) that your image is off-topic. It's just a calculator, not even turned on. Do you propose to add that to every article that has a formula in it? Do you suppose that the readers are idiots who wouldn't guess how to calculate the formula without such an image? --David Eppstein (talk) 05:39, 16 October 2014 (UTC)

To answer your first question, "No." It is an unusual tool to keep in a typical kitchen for cooking purposes. I have read portions of many cookbooks in my 50+ years, and have never seen a calculator presented as a tool typically used in a kitchen, but have seen a number of drawings or pictures of measuring cups and spoons presented in those same books along with other equipment. To answer your second question about idiocy, "No." On the other hand, I do believe ignorance is possible. Gzuufy (talk) 14:48, 16 October 2014 (UTC)

I agree with David. A giant image of a calculator takes up precious screen real estate without adding anything of value to the article. (Although it is possible you might get a different reaction by asking a more relevant Wikiproject like something to do with cooking.) S?awomir Bia?y (talk) 17:23, 16 October 2014 (UTC)

It appears there's some consensus, with three folks believing it inappropriate. That's fine, I'm not going to shop around for the answer I want. Thanks for your answers! Gzuufy (talk) 19:15, 16 October 2014 (UTC)

Terminology

I think that in general, Wikipedia math articles would benefit from having a short section about the terminology of the different symbols that are used, as many articles seem to lack some or much of that. For example, what is the variable that is written under the summation sign in a series called; is it the "summation variable"? Is there anything that can be done about this to increase the overall quality of math articles in this aspect? --Kri (talk) 12:47, 18 October 2014 (UTC)

Should Lie theory be merged to Lie group

Hi all,

It seems there is a disagreement among editors as to whether Lie theory should be merged into Lie group. I'm in favor of merger as the former doesn't have much materials and the term is also somehow vague. For example, how much the representation theory of Lie groups a part of Lie theory? In any case, more inputs will help. -- Taku (talk) 11:10, 11 October 2014 (UTC)

I'll respond here, because I see this as part of a larger issue. We have an article on Ring theory, although ring theory is merely the study of Ring (mathematics). We have an article on Group theory, although group theory is merely the study of Group (mathematics). And so on. These articles end up with strange divisions of labor, that I've never seen systematized or explained.

I'm not sure that Lie theory merits its own article, but it has at least as much merit as group theory or ring theory. I'm not even sure that Lie groups are the central object of the theory; maybe Lie algebras are. Mgnbar (talk) 17:18, 11 October 2014 (UTC)

Absolutely no merger. Lie theory is the framework inside which Lie groups, Lie algebras and more sits. It is fairly technical, so the Lie theory article should be an overview article with supporting detailed articles like Lie group, Closed subgroup theorem and Lie correspondence etc. YohanN7 (talk) 18:03, 11 October 2014 (UTC)

Also, representation theory is not part of Lie theory, though it rests heavily on the Lie correspondence. YohanN7 (talk) 18:04, 11 October 2014 (UTC)

For a good overview of what Lie theory is (the main applications of today), see John M. Lee, Introduction to smooth manifolds (mostly ch. 20), Wulf Rossmann, Lie groups and Lie algebras: An introduction through linear groups (mostly ch. 2) or Brian C. Hall, Lie groups, Lie algebras and Representations (mostly ch 3). There is also more to it, like "local groups" and the study of differential equations. YohanN7 (talk) 18:17, 11 October 2014 (UTC)

Actually, Lie theory might warrant a category of its own. I can think of some 15-20 (potentially new) articles in such a category. That would be a long-term project though. YohanN7 (talk) 18:35, 11 October 2014 (UTC)

This comment is a great example of my point. YohanN7 reasonably proposes that Lie theory give an overview, leaving the details to other articles. But Group theory explicitly states that it covers advanced notions (although it doesn't) and leaves the basics to Group (mathematics). That's what I meant by "strange divisions of labor, that I've never seen systematized". Mgnbar (talk) 19:06, 11 October 2014 (UTC)

"Group theory" is not a great article and its hatnote is probably a bit misleading or dated, but I can see that there is separate scope for a topic "Group theory" as distinct from "Group (mathematics)". Group theory is a huge area of mathematics. "Group (mathematics)" concerns the basic notions and their applications, and "Group theory" gives a description of the area of mathematics and its basic subdivisions. S?awomir Bia?y (talk) 21:32, 11 October 2014 (UTC)

Indeed, is there any great "theory" article among math articles? I think the problem with these types of articles, as I alluded, is that the scope is not clear and most of times they seem to duplicate materials in more specialized articles. Also, from the quality assurance point of view, it is much more important to keep main articles such as Lie group and group (mathematics), as, presumably, the main articles as opposed to the theory articles are far more visible to the readers. (Of course, if some other editors want to work on them, I'm not going to interfere.) -- Taku (talk) 21:58, 11 October 2014 (UTC)

I totally agree with your observation about the current state of affairs, but should these deficiencies make us reorganize in an illogical way? Lie theory has more than enough mention (and definition of what it is) in the literature to warrant an article. I'd be utterly surprised if I was redirected to "Lie group" or "Lie whatever" if I typed "Lie theory" in the search box. A student about to chose courses may want to know a little about the general topic (often the name of the course or mentioned in the description). By the way, the essence of Lie theory (yes, I can source that statement) is captured in the article that you wrote YohanN7 (talk) 22:47, 11 October 2014 (UTC)

Actually, I think we should proceed the other way around. Sections 8, 9, and 10 in Lie group should be reduced to a minimum, the material could be distributed to Lie theory and the relevant specialized articles, e.g Baker-Campbell-Hausdorff formula. Our really important articles, of which Lie group is one, tend to be cluttered with stuff in attempts to be complete regarding the surrounding theory. They aren't clean, and much space is devoted to cover marginal topics that only a few personally involved mathematicians really care about. I think that out of 100 persons looking up Lie group, only 1 is interested in anything else than a fairly in-depth description of real or complex Lie groups, not paraphernalia. Who goes to Lie group to find out about "p-adic Lie groups"?

A related phenomenon is that whenever fields are involved, much space (and confusion for many uninitiated readers) is devoted to disclaimers about finite fields, especially of characteristic 2. Most or all of such stuff could be hidden under pop-ups. YohanN7 (talk) 00:08, 12 October 2014 (UTC)

The idea that we use the "theory" article to keep the main article (e.g., group - group theory, ring - ring theory) short or in reasonable length does make sense. This may even be the answer to Mgnbar's "strange subdivisions" (I too have always found the divisions strange and unclear.) But to me this is the argument "in favor of merger": Lie group isn't long enough to warrant distributions of materials to spin-off artciles. Meantime. the consensus seems clear (non-merger) for now. -- Taku (talk) 11:29, 14 October 2014 (UTC)

I don't think length by itself can be used to argue in one or the other direction. What I am looking for is a logical subdivision of the material. Old Sophus had no idea about what manifolds are, so he didn't know about Lie groups. Lie theory is both much more and much less than Lie groups.

I have, on the talk page, proposed material, pertaining to Lie groups in particular, that very much belongs in the article, but is missing. I have also raised the issue of differentiable versus analytic in our definition of Lie group. The latter issue may be worth a discussion. YohanN7 (talk) 18:20, 14 October 2014 (UTC)

There is an important difference between whether a topic merits its own article and whether we should be working on the topic at all. The priority should be proportional to visibility to readers. Lie group and Lie algebra are pretty visible and the standards on them should be pretty high as well. In other words, if this is the goal, then it is easier for us not having Lie theory as a separate article. As for the division of materials, the article title Lie theory is not helpful since it's too vague. But I guess, in any case, what matters if there is some editor who wants to work on it. Building good materials is more important since we can always mess with organizations. -- Taku (talk) 15:10, 18 October 2014 (UTC)

"Cantor's first uncountability proof" is a "good article" nominee

I have nominated Cantor's first uncountability proof for "good article" status. The article in its present form was written mostly by Robert J. Gray, a historian of mathematics who has published on this and related topics in refereed journals. Michael Hardy (talk) 16:36, 20 October 2014 (UTC)

Natural number

A new editor is insisting on major changes to the lead of natural number without waiting for consensus. Please take a look. --Trovatore (talk) 04:57, 5 October 2014 (UTC)

This needs the attention of experienced editors before the situation gets out of hand. There is a bit of an invasion there by a few IP's. One of them is currently attacking an established editor with vicious threats on his talkpage. The issue seems to be whether the term "counting number" should be included on par with "natural number" and "whole number" in the lede. It seems that "counting number" is a primary school term that is not in common usage among people likely to use wiki, but the IP's insist on retaining it. Tkuvho (talk) 08:17, 15 October 2014 (UTC)

There is now a conflict resolution entry for this: https://en.wikipedia.org/wiki/Wikipedia:Dispute_resolution_noticeboard#natural_numbers Experienced editors are invited to contribute. Tkuvho (talk) 10:02, 17 October 2014 (UTC)

The current discussion at Talk:Natural_number#equivalent could benefit from the attention of our resident logicians and set theorists. Tkuvho (talk) 14:00, 21 October 2014 (UTC)

I am not one of these, :-) but I did participate a little, anyway. Boris Tsirelson (talk) 16:33, 21 October 2014 (UTC)

"Hilbert-Bernays paradox" is an orphan

Currently no articles link to Hilbert-Bernays paradox. Michael Hardy (talk) 17:20, 23 October 2014 (UTC)

Vera de Spinadel and metallic means

Is Vera de Spinadel a notable academic? Her work appears to be primarily on the metallic means, an article that is also on AfD. S?awomir Bia?y (talk) 11:37, 17 October 2014 (UTC)

I have nominated Vera de Spinadel for deletion, here. S?awomir Bia?y (talk) 19:55, 23 October 2014 (UTC)

Request for help copyediting Heart_valve#Physiology

Hello Mathematics editors! I come from the far-off Wikiland of WP:ANATOMY and humbly beseech any kind editors here to fix the wikicode used to represent some formulas on this article: Heart_valve#Physiology. Any additional thoughts or comments or edits to the article are also welcome. Cheers, --Tom (LT) (talk) 23:51, 26 October 2014 (UTC)

sockpuppet investigations of long-standing project participants

I would much appreciate if someone could take a look at this and comment. Tkuvho (talk) 10:29, 28 October 2014 (UTC)

Indeed, someone needs to step up and just indef Carmella1. That would solve the problem. S?awomir Bia?y (talk) 13:35, 28 October 2014 (UTC)

This concerns the infamous two envelope problem. Great fun, lots of confusion. Badly needs some sensible mathematicians to look at it. Richard Gill (talk) 09:11, 29 October 2014 (UTC)

Unfortunately User:Caramella1 has continued harassing fellow editors, as in this edit. Tkuvho (talk) 11:21, 29 October 2014 (UTC)

I started an ANI thread here. S?awomir Bia?y (talk) 11:43, 29 October 2014 (UTC)

Hat at number

Does Number need a fancier hat? Tkuvho (talk) 17:58, 30 October 2014 (UTC)

Tkuvho post is about this edit [51], and another similar edit by the same editor. D.Lazard (talk) 18:44, 30 October 2014 (UTC)

Nov 2014

Please help review a submission at AFC

Please review Draft:Lie bialgebroids -- Roger (Dodger67) (talk) 14:48, 31 October 2014 (UTC)

The title was inappropriately plural. I changed it to the singular. I also did some punctuation editing and the like. So far only one other article links to it. Michael Hardy (talk) 15:57, 1 November 2014 (UTC)

Arrowhead matrix

A COI edit stopped by a filter is discussed at Wikipedia:Help desk#Edit triggered a filter. Review by an editor with matrix knowledge is needed. PrimeHunter (talk) 00:03, 4 November 2014 (UTC)

Ivar Stakgold

I expanded the new biography Ivar Stakgold greatly (previously a {bridge-game-stub}). As academic applied mathematician he earned a 70th birthday volume in his honor, c1996. WP:CAT {20th-century mathematicians} altho he is living, emeritus. {maths rating} on the Talk page.

I used as sources Library of Congress online catalog records and enhancements and the Mathematics Genealogy Project, with some references that are fullish but free form. Planning to leave a notice here, I provided fullish edit summaries and some comments (especially at Ivar Stakgold#Books). I hope they help.

--P64 (talk) 20:00, 4 November 2014 (UTC)

fullish. adj. Meaning, rather full. Pronunc., full-ish or foolish. -P64

MathML rendering available

An announcement at the wikitech-l mailing list says that logged-in users now have an option to enable MathML rendering at Special:Preferences#mw-prefsection-rendering. I think it's saying that Internet Explorer would fallback to SVG. Also, there are a couple of editing tricks (create an anchor and display inline/block). Johnuniq (talk) 02:21, 24 October 2014 (UTC)

I'm impressed; the big formula in squared triangular number (the one in the proofs section) looks pretty good with this option, and the formulas in the reference titles are correctly sized. (I'm less impressed that you broke my previous preference setting for MathJax, but never mind.) One issue I noticed, though: we have a bunch of formulas in which editors have included \scriptstyle in order to try to get the formula size produced by the old bitmap renderer closer to the text size. Doing that with the MathML option is a bad idea; it actually comes out subscript-sized (just what you asked for but way too small). So I think the best option for these is to remove the \scriptstyle command, but in some cases \textstyle may be needed instead (e.g. look at the references of squared triangular number -- I've used textstyle there because otherwise the formulas in the titles come out way too big). Another issue: the baseline of the formulas doesn't match the baseline of the text. That's annoying enough to me that for now I think I'll stick with MathJax. (This is all on Chrome for OS X btw; presumably these rendering issues will differ for different platforms.) --David Eppstein (talk) 02:54, 24 October 2014 (UTC)

I really like this so far. Formula looks a lot better, for instance.Brirush (talk) 03:06, 24 October 2014 (UTC)

I've reopened bug 32694http://bugzilla.wikimedia.org/show_bug.cgi?id=32694 which addresses baseline issues.

For what its worth only Firefox has decent MathML support and Chrome will fallback to SVG. --Salix alba (talk): 06:43, 24 October 2014 (UTC)

The jury is still out for me on this one. The \scriptstyle command, seemingly ignored by MathJax, does result in an unacceptable rendering with MathML. I've removed them from one article (Square root), but this was a lot of work ... could someone write a bot to do this? Also, the baseline problem does need to be dealt with. In said article there was an instance of two radicals appearing at different heights wrt the baseline on the same line of text. I used \phantom as a kludge to get the heights right, but then the radical sign extends too far (in order to cover the phantom letter) ... I left it that way as the lesser of two evils. Editors will be spending far too much time on these appearance issues unless something is done relatively quickly. Bill Cherowitzo (talk) 19:01, 24 October 2014 (UTC)

Better, but not good enough (Chrome on Windows). The math is displayed in a (too) bold typeface - and there is, as mentioned, the baseline problem. This is still unacceptable for inline LaTeX. YohanN7 (talk) 01:55, 27 October 2014 (UTC)

As noted above. Only Firefox (and other Gecko engine based browsers) has proper support for MathML. For other browsers (including Chrome) this setting will just fall back to SVG rendering (which is suboptimal).TR 09:39, 27 October 2014 (UTC)

I'm fairly optimistic that things will get better quickly on this. Physikerwelt, Frédéric Wang and other have done great work getting basic system going. This has been tricky as it involves large changes in the code which are hard to get through code review. Now thats out of the way the smaller tweeks to the system should be easier to do. There has been quite a bit of traffic on the baseline bug including input from the main MathJax person. I've started a new bug about the font size bug 72553http://bugzilla.wikimedia.org/show_bug.cgi?id=72553 it would be helpful if people could add to that as its quite a browser dependant issue.

@Wcherowi: For the \scriptstyle in square root, I could not quite see why it was used in the first place. The best way to do derivative inline might be to use \tfrac \tfrac{dy}{dx}=3x^2

{\tfrac {dy}{dx}}=3x^{2}

or {\scriptstyle \frac{dy}{dx}}=3x^2

{\scriptstyle {\frac {dy}{dx}}}=3x^{2}

with the \scriptstyle in { } so the whole equation is not rendered small. I'm generally against specific hacks to make the equation look nice as there are so many different ways to view equations and a hack might work in one method and not another.--Salix alba (talk): 10:25, 27 October 2014 (UTC)

Thanks for that example. It both shows an appropriate use of \scriptstyle and implies why a bot would not be such a good idea. I agree with your position on specific hacks. I was experimenting in square root and don't usually engage in such behavior. Bill Cherowitzo (talk) 19:40, 27 October 2014 (UTC)

Looks good in Firefox, albeit slightly too small on Windows. That is because the size for the (defualt serif) font is not adjusted to fit the page's sans-serif font. Firefox' internal fontstack for MathML is

"MathJax_Main, STIXGeneral, Cambria, Cambria Math, XITS, Latin Modern Math, DejaVu Serif, DejaVu Sans, Times, Lucida Sans Unicode, OpenSymbol, Standard Symbols L, serif;"

. I happen to have STIX fonts installed, but Cambria (which 99% of Windows users will see) is equally small. So if possible (that is, if Firefox supports it), you may need some CSS to increase the size. -- [[User:Edokter]] {{talk}} 11:54, 27 October 2014 (UTC)

I've just noticed a bug when an equation contains a percent. <math>P = 10%</math> now cause a bug $P=10\%$ it should be <math>P = 10\%</math> giving $P=10\%$ . I think the old texvc system managed to parse this OK. I'm doing a scan to find all the pages where this occurs.--Salix alba (talk): 20:35, 27 October 2014 (UTC)

That would cause an error in LaTeX, too, so I think the bug is in the formula rather than in the MathML implementation. --David Eppstein (talk) 20:57, 27 October 2014 (UTC)

Yes the latex formula need to be fixed. I've compiled a list User:Salix alba/percent bug of the 250 or so articles which may contain the bug. I've corrected some of them but there is still about half to do. The list is generated from the September dump so there will be other articles with the bug.--Salix alba (talk): 23:37, 27 October 2014 (UTC)

The bug for darkness of the font is bug 71958http://bugzilla.wikimedia.org/show_bug.cgi?id=71958. It is currently wontfix as its device dependant.--Salix alba (talk): 08:23, 28 October 2014 (UTC)

I've now hopefully fixed all the cases of percentages causing problems. Strangely the presence of an unescaped percentage did not always cause the red error message, sometimes is just didn't display the percent, which is harder to spot. There are a couple of other rendering bugs I've noticed.

The \textrm command causes a couple of problems. With png rendering it needs \, to force spaces between words and spaces are ignored so <math>\textrm{A\,B C}</math> is rendered as "A BC". In MathJax <math>\textrm{A\,B C}</math> is rendered as "A\,B C". The solution is to change to the \text command which preserves spaces.

Setting the vertical-align style <math style="vertical-align:-10%;">B</math> (

B

) renders the equation invisible when using the mathml or SVG fallback in chrome. I think this is a bug in the system bug 72626http://bugzilla.wikimedia.org/show_bug.cgi?id=72626 rather than with the syntax, although all the instances I've found seem to be workarounds for the baseline problem.--Salix alba (talk): 09:33, 29 October 2014 (UTC)

MathML accepts characters such as ?. I noticed this when translating from HTML to LaTeX (missing the ?) and then later switched to PNG rendering. I don't know if this should be considered a feature or a bug. See for yourself below.

YohanN7 (talk) 11:08, 29 October 2014 (UTC)

Info: You can report bugs and give suggestions at mw:Extension:Math/Roadmap. Best wishes, --Quartl (talk) 07:34, 5 November 2014 (UTC)

This doesn't work

I set my preferences for MathML and then I could no longer see anything coded in TeX. All I see is "[Math Processing Error]". This persists even after I've changed my preferences back to what they were. Michael Hardy (talk) 06:16, 5 November 2014 (UTC)

You are still loading Nageh's obsolete MathJax script from your vector.js. Remove it and MathML should work. -- [[User:Edokter]] {{talk}} 06:59, 5 November 2014 (UTC)

A new feature

https://lists.wikimedia.org/pipermail/wikitech-l/2014-October/079144.html

For editors, there are also two new optional features:

1) You can set the "id" attribute to create math tags that can be referenced. For example, the following math tag

<math id="MassEnergyEquivalence"> E=mc^2 </math>

can be referenced by the wikitext

[[#MassEnergyEquivalence|mass energy equivalence]]

This is true regardless of the rendering mode used.

Michael Hardy (talk) 15:18, 5 November 2014 (UTC)

What is the second feature? -- Taku (talk) 16:54, 5 November 2014 (UTC)

It's explained in more detail in the link, but it's a way of doing \textstyle or \displaystyle in the html part of the encoding rather than in the latex part. --David Eppstein (talk) 18:22, 5 November 2014 (UTC)

Wikipedia talk:Articles for creation/Saddlepoint approximation

Hello mathematicians. This old AfC submission will soon be deleted as a stale draft. Is this a notable topic, and should the page be kept and improved instead? --Anne Delong (talk) 12:44, 6 November 2014 (UTC)

It's definitely a notable topic (although pretty far from my own areas of expertise). I'm a little puzzled by the decline reason, as the AfC draft cites two books on the subject of the article by reputable academic publishers. It's not a great article at the moment, but pushing it out into the main space may be a way to solicit improvement by normal editing. What do others think? S?awomir Bia?y (talk) 12:49, 6 November 2014 (UTC)

The style needs work, but besides that I think the article is fine. The topic is notable, and the citations are adequate per WP:SCICITE. Ozob (talk) 14:30, 6 November 2014 (UTC)

I agree that this topic is notable and lack of inline citations shouldn't prevent a transition to mainspace. But we already have an article on Method of steepest descent, of which the saddle-point approximation is a synonym. Hence a merge may be best. --Mark viking (talk) 16:31, 6 November 2014 (UTC)

(sigh) Thanks, S?awomir Bia?y, Ozob and Mark viking; I wish I could do this merge but I don't have the knowledge. If someone here will move the text, I will be happy to handle the attribution stuff. --Anne Delong (talk) 19:10, 6 November 2014 (UTC)

I think it is unlikely you will find volunteers on a short notice, but how about just approving the article and tag it with " suggested merge"? YohanN7 (talk) 19:20, 6 November 2014 (UTC)

I am not sure whether "saddle-point approximation" is a synonym of "method of steepest descent" or not, but I see that this article "Saddlepoint approximation" describes only the real-valued case. No contour integrals on the complex plane, no complex numbers at all. This makes it less general, and accordingly simpler, more accessible. It is also written in the probabilistic language (still more accessibility for some audience). And it is shown that this special case is indeed useful for some applications. If merge them, then probably the merged article should be nearly the "direct sum" of the two articles. That is, two separate sections, with some common lead. Or not to merge them? Boris Tsirelson (talk) 20:21, 6 November 2014 (UTC)

But wait; maybe it should rather be merged with Laplace's method? Indeed, Laplace's method#Example 1: Stirling.27s approximation and Wikipedia talk:Articles for creation/Saddlepoint approximation#Examples could be a single list. Boris Tsirelson (talk) 20:25, 6 November 2014 (UTC)

Fréchet space

I post this here because I suspect the page has few watchers. I find the article very nice, it is crisp and clear. The page rating should be changed, but there is not a single inline citation. I can (and will) add a couple, but my access to functional analysis literature is limited (to John B Conway's A course in Functional Analysis). Some help appreciated. YohanN7 (talk) 16:04, 6 November 2014 (UTC)

Maybe try to contact User:Robert McGuigan=User:RMcGuigan, the originator of "LF-space" in 2005, last seen in May 2014. Boris Tsirelson (talk) 21:17, 6 November 2014 (UTC)

Symmetry: Splitting off geometry section

On Talk:Symmetry, I have proposed a major revision to symmetry which would remove the geometry portion and replace it with low-difficulty description and link to the new page, as well as simplifying the physics portion by moving relevant material to the pre-existing article symmetry (physics). I have a sample draft available at User:Brirush/sandbox, and I would be interested in hearing feedback before taking any action.Brirush (talk) 18:52, 9 November 2014 (UTC)

A remark: scale symmetry is not isometric. Otherwise, yes, looks good. Boris Tsirelson (talk) 19:20, 9 November 2014 (UTC)

Good catch! I removed the offending line.Brirush (talk) 20:09, 9 November 2014 (UTC)

Redirect for "Numbers"

There is a discussion at Wikipedia:Redirects for discussion/Log/2014 November 4#Numbers for deciding if Numbers should remain a redirect to Number or should be redirected to Number (disambiguation). Further opinions are needed to reach a consensus. D.Lazard (talk) 16:53, 12 November 2014 (UTC)

Inductive probability

Can someone check if the article Inductive probability makes any sense? --Ruud 09:43, 13 November 2014 (UTC)

The article doesn't make much sense to me, in that it seems to be a big synthesis of Bayesian inference, mutual information, algorithmic complexity, and other concepts into some original research. It seems related to Solomonoff's theory of inductive inference, another problematic article. There does exists a notion of inductive logic and inductive probability in philosophy; the Stanford Encyclopedia of Philosophy article has a nice summary of the different approaches tried and we have a a start of an article on it in Inductive reasoning. --Mark viking (talk) 10:29, 13 November 2014 (UTC)

It seems reasonable, but it is too long and repetitive. And reads like a textbook. JRSpriggs (talk) 10:32, 13 November 2014 (UTC)

This quotation from the user's talkpage does not inspire a lot of confidence:

Also I have done the maths as text, which works alright because the maths is not difficult. However I dont have references (other than to other wiki pages). Honestly I find it difficult to read scholarly articles. I am not an academic. So maybe my page is not useful to anyone else. Thats OK.

Maybe some more careful checking is warranted. Rschwieb (talk) 14:59, 13 November 2014 (UTC)

Draft:Reckless Xi function

Dear mathematicians - is there anything in this old draft that should be kept? --Anne Delong (talk) 23:57, 13 November 2014 (UTC)

Nope. At best, it's self-named original research. The OEIS entry referenced in the article is written by someone claiming to be "Frederick Reckless", but there is no evidence that such a person actually exists. It seems likely that this is a hoax. Oh, and someone should probably ping User:CRGreathouse to look into the OEIS entry. S?awomir Bia?y (talk) 00:35, 14 November 2014 (UTC)

Thanks for the heads-up. It looks like OR to me, more than a hoax -- the math checks out, as best I can tell, though of course it doesn't meet the notability guidelines.

Modulo the (nontrivial) issue of attribution, the OEIS sequence looks fine to me.

CRGreathouse (t | c) 05:35, 14 November 2014 (UTC)

Alexander Grothendieck

I'd like to let you know about the nomination of the article Alexander Grothendieck for ITN at Wikipedia:In the news/Candidates#Alexander Grothendieck. It isn't posted yet due to concerns on article quality, mostly referencing. Cenarium (talk) 14:36, 15 November 2014 (UTC)

There has been some grumbling at Talk:Alexander Grothendieck#Jargon and Sources - a need for in text clarification that the mathematical works of Grothendieck should be made understandable to someone who doesn't know anything. Perhaps editors here more familiar with his works than I would care to weigh in on the futility of that request. S?awomir Bia?y (talk) 20:45, 15 November 2014 (UTC)

An anecdote: many years ago I gave a talk "The Grothendieck constant in physical laboratory" in France, and the audience was very disturbed and angry. I did not understand, why, and asked a friend. The answer was that I took a tiny result of Grothendieck, not worth to be mentioned, which was an insult for his admirers... Boris Tsirelson (talk) 21:51, 15 November 2014 (UTC)

It is getting rather exasperating dealing with User:Medeis, who citing his own ability to express elementary biological facts in a way that any educated lay person can understand, seems to believe that all concepts can therefore be expressed by some sort of sound-bite. Moreover, he refers to WP:JARGON and WP:MTAA without (apparently) having read or understood either. Please see his rather baffling assertions concerning accessibility at Talk:Alexander Grothendieck and Candidates#Alexander_Grothendieck. S?awomir Bia?y (talk) 01:43, 16 November 2014 (UTC)

It is now on the main page, under recent deaths with no blurb. Could the one liner in Deaths in 2014 be improved to say more than just one a field medal? --Salix alba (talk): 09:07, 16 November 2014 (UTC)

Richard Feynman said (something like) "I can't teach you how to understand quantum theory, because I don't understand it." The problem is that quantum theory requires some difficult math and violates a lot of our common sense. Grothendieck's work requires much more difficult math (at least at the start). Because it's not about reality, it doesn't violate much common sense, but it's very hard to motivate to the non-mathematician.

My point is that making Grothendieck's work accesssible would be a feat, perhaps worthy of a prize itself. So we can use this occasion to improve the articles on Grothendieck, including citations, but making them truly accessible in a few days seems too ambitious. Mgnbar (talk) 14:59, 16 November 2014 (UTC)

I fully agree. The basic starting point of his whole work in algebraic geometry is the introduction of the notion of scheme. This definition involves commutative algebra, topology, sheaf theory and category theory, and, for being well understood, requires to understand an analogy with manifolds. And this is the first hundred pages of a work of thousands of pages! D.Lazard (talk) 15:43, 16 November 2014 (UTC)

Formula overload in Artin transfer

I can't view Artin transfer (group theory) (primarily edited by DanielConstantinMayer (talk · contribs)) when logged in -- it's ok logged out or probably with different math rendering preferences -- because it's huge and packed with formulas that cause the Wikipedia servers to choke. Instead I get the error message "Sorry, the servers are overloaded at the moment. Too many users are trying to view this page. Please wait a while before you try to access this page again. Timeout waiting for the lock".

I was looking at it to see what should be done about the proposed merge between this and Transfer (group theory), which appears to be on the same topic in much more high-level terms. The "Transfer" article is not much more than a stub, but I think the other one goes too far to the other extreme, so some trimming and attention to WP:TECHNICAL is in order. Maybe some group theory expert here would like to take this on? --David Eppstein (talk) 07:07, 16 November 2014 (UTC)

I have no problem viewing the page; perhaps it depends on the math rendering system used. But holy smokes, that is a lot math formulas, badly formatted and mostly unexplained. Beyond the lead, it reads more like a terse journal article than an encyclopedia article. It also seems to lean pretty heavily on D.C. Mayer's publications, but I don't know enough of this field to determine whether this is a COI issue. --Mark viking (talk) 07:44, 16 November 2014 (UTC)

Perhaps we should just redirect Artin transfer (group theory) to Transfer (group theory), and let others debate what should be in it other than Mayer's paper. -- Arthur Rubin (talk) 06:58, 17 November 2014 (UTC)

I tried PNG, MathML and MathJax (all with Firefox on Windows). MathJax, of course, takes forever. (The article, b t w, illustrates why the use of inline LaTeX should carry a lifetime sentence, or at the very least, a sentence of a few years behind bars ) YohanN7 (talk) 15:59, 16 November 2014 (UTC)

Yup, MathJax can't handle this, strange though that the server pukes. YohanN7 (talk) 16:04, 16 November 2014 (UTC)

The practice of creating detailed articles in the field of your own research and then subsequently sneaking in references to your own very recent publications (see also Principalization (algebra)) should at least be looked at closely, the more so because it is not a very blatant WP:COI in this case. YohanN7 (talk) 17:03, 16 November 2014 (UTC)

Diophantus spam

User talk:Morcohen2 insists on adding material on Diophantus that's not properly sourced. He did it twice from his account and once from IP in the past 24 hours. Tkuvho (talk) 13:17, 18 November 2014 (UTC)

User talk:Morlvi seems to be a sockpuppet based on edit history. Tkuvho (talk) 13:21, 18 November 2014 (UTC)

Apart from the issue of sourcing, the added content states a matter of opinion (that the title "father of algebra" ought to belong to Diophantus instead of al-Khw?rizm?). A comparison might indeed be appropriate, but we cannot advance unattributed opinions. S?awomir Bia?y (talk) 13:25, 18 November 2014 (UTC)

We now have some further insights by the same editor here: https://en.wikipedia.org/w/index.php?title=History_of_algebra&diff=prev&oldid=634376716 Tkuvho (talk) 14:06, 18 November 2014 (UTC)

Since the editor is very new, I'm not sure that the use of multiple accounts is malicious. I've asked him on his talk page to create user pages which identify the accounts as alternates. Ozob (talk) 15:20, 18 November 2014 (UTC)

more upright d's

Please help with this https://en.wikipedia.org/w/index.php?title=Leibniz%27s_notation&oldid=634556411&diff=prev and there is a similar development taking place at derivative. Tkuvho (talk) 18:46, 19 November 2014 (UTC)

Draft:360360

Is this a collection of trivia or does it deserve a place on WP? Roger (Dodger67) (talk) 20:43, 18 November 2014 (UTC)

Lean toward exclusion; all the interesting facts are already in the "360360" entry in 100000. -- Arthur Rubin (talk) 21:51, 18 November 2014 (UTC)

Of the facts presented about 360360, I can't detect a single noteworthy or interesting one, except perhaps that it is highly composite (?). Also the tone is unencyclopedic ("infamous") and unclear (is it highly composite?). Mgnbar (talk) 03:09, 19 November 2014 (UTC)

I disagree that there is nothing interesting about this number, but I don't think there's enough. I think being the lcm of the first few positive integers is interesting. But when I searched this number on OEIS, the only interesting properties of this number that I found all seemed to be minor variants of this, and that WP:NUMBER requires at least three independent interesting properties. --David Eppstein (talk) 03:53, 19 November 2014 (UTC)

Hi all, if you do decide that it's a notable topic, would you mind pinging me so I can fix/approve the page? Otherwise I'll just link to this discussion as a reason not to approve the article. Cheers, Primefac (talk) 20:01, 19 November 2014 (UTC)

Category:Zero and Category:One

The naming of Category:Zero and Category:One is under discussion, see Wikipedia:Categories_for_discussion/Log/2014_November_19#Numbers] -- 67.70.35.44 (talk) 07:34, 20 November 2014 (UTC)

Singles and plurals and distribution families

An issue has come up at Student's t-distribution, where a user doesn't like the existing phrasing, "In probability and statistics, Student's t-distribution (or simply the t-distribution) is a family of continuous probability distributions that arise when... " -- complaining that the subject-verb agreement is wrong.

He's made three alternative proposals so far, most recently diff, none of which seem to me to work.

Apparently he finds the existing version "awkward and bizarre" (as he put it in a lengthy discussion on my talkpage). It seems fairly regular mathematical usage to me. But, rather than the two of us just go backwards and forwards, it does seem to me that we could use some external input here. So, although it seems rather a trivial thing to bring here, I would be grateful for some wider community input. Thanks, Jheald (talk) 23:32, 20 November 2014 (UTC)

Quotient by an equivalence relation

Quotient by an equivalence relation is an article that can be immensely improved. Remind me to look at it some time over this weekend. (And look at it yourself!) Michael Hardy (talk) 04:54, 22 November 2014 (UTC)

The concept of "quotient by an equivalence relation" is defined and studied in Equivalence class, which is a redirect from quotient set and quotient space. This generalization to category theory and scheme theory must have another title such as quotient (category theory). D.Lazard (talk) 09:53, 22 November 2014 (UTC)

I must admit there might be a better title. There "is" a generalization of a quotient in equivalence classes to category theory and that is called a coequalizer. The article in question is about a special case, which is important and deserves its own article (whence one). Unfortunately, the most common term is just "quotient" (by f). -- Taku (talk) 13:23, 22 November 2014 (UTC)

Match-3 games are NP-hard

Luciano Gualà, Stefano Leucci, Emanuele Natale (24 March 2014). "Bejeweled, Candy Crush and other Match-Three Games are (NP-)Hard". arXiv:1403.5830 . Bibcode:2014arXiv1403.5830G. CS1 maint: Multiple names: authors list (link)

There's been a few studies (such as the one above) on the issue, might be something to update various match 3 game articles with, to add a mathematical/educational context -- 67.70.35.44 (talk) 10:33, 24 November 2014 (UTC)

Talk:Ellipse#Circumference

Although I am for the moment assuming good faith, I'm having a harder and harder time believing that I'm not being messed with by the OP there. Does anyone have any suggestions on how to respond to future replies, if any appear?--Jasper Deng (talk) 02:06, 25 November 2014 (UTC)

Why do you need to explain to this person that they are wrong? The talk page is not a classroom nor a discussion forum. --JBL (talk) 02:10, 25 November 2014 (UTC)

Exactly my thoughts. At least he isn't inserting that nonsense into articles. I completely agree that it's quickly getting contrary to WP:NOTAFORUM.--Jasper Deng (talk) 02:11, 25 November 2014 (UTC)

I've collapsed it; I doubt any further replies would help solve whatever problem the OP has, and it has nothing to do with improving the article.--JohnBlackburne^words_deeds 03:14, 25 November 2014 (UTC)

Breaking up topos

I have started a discussion on whether it makes sense to separate the article topos into two articles: one on math, the other on logic. The feedbacks are very welcome. -- Taku (talk) 05:14, 28 November 2014 (UTC)

Good article nomination: Addition

I have nominated addition as a good article. It is well-sourced, covers all major topics, etc. Due to the simple nature of the subject, it should not take someone with an advanced background to review it (I believe it mentions Dedekind cuts, but that's about as bad as it gets). Link:Wikipedia:Good_article_nominations#Mathematics_and_mathematicians Brirush (talk) 00:03, 30 November 2014 (UTC)

Homothety

Should homothetic transformation and homothetic center really be two different articles? Michael Hardy (talk) 23:27, 30 November 2014 (UTC)

Dec 2014

A new redundant category

Greenrd (talk · contribs) has created Category:Foundations of mathematics which is redundant with Category:Mathematical logic. JRSpriggs (talk) 08:47, 1 December 2014 (UTC)

According to Topics in mathematics in Portal:Mathematics, the latter is a subset (subcategory) of the former. Just noting, I have no opinion. YohanN7 (talk) 09:21, 1 December 2014 (UTC)

Two articles in Category:Foundations of mathematics are already in Category:Systems of set theory which is in Category:Set theory which is in Category:Mathematical logic. And Category:Foundations of mathematics is in Category:Fields of mathematics which already contained Category:Mathematical logic. This is as one would expect since "Mathematical logic" and "Foundations of mathematics" are synonyms. JRSpriggs (talk) 09:37, 1 December 2014 (UTC)

I disagree that "Foundations of mathematics" and "Mathematical logic" are synonyms: For taking a simple example, Automated theorem proving and category:Automated theorem proving? belong naturally to "Mathematical logic" and are far to belong to the foundations of mathematics. On the other hand, the foundations of mathematics clearly involve philosophical and epistemological questions which do not belong to mathematical logic. The debates between constructive analysis and non-standard analysis vs. classical analysis are examples of questions of foundations of mathematics that do not belong to mathematical logic, as involving the same logical foundation. D.Lazard (talk) 10:56, 1 December 2014 (UTC)

Can you help with an excessive quotation issue?

An IP brought up concerns at the copyright problems board about the extensive quotation at Josip Plemelj - from the third paragraph under "A geometrical construction from his schooldays" to the end is a quote. Investigation confirms that this material is likely under copyright, which means that the IP is right that the quotation doesn't comply with copyright policies. WP:NFC forbids extensive quotation. I would really prefer to ask somebody to help turn that into a proper paraphrase than to blank the section - I think it's quite unlikely that I could paraphrase it myself, since the material is so far from my realm. Would any of you be able to help out with this? If not, I can of course apply the usual {{copyvio}} template to the section in hopes that somebody else will. But with a case like this one, I really hate to do that. :) If there's no takers, it'll probably be blanked in a day or so and removed or truncated in about a week. --Moonriddengirl ^(talk) 11:58, 20 November 2014 (UTC)

This strike be a bit odd, since while still possibly being a copyvio it is certainly no verbatim quote as the original source is in Slovenian and not in English. So the question here is whether the "translation" is too literal/close to the original. One option of course would be imply to rewrite the mathematical content as it is, but it certainly would preferable if we get Slovenian speaker who can verify the IP claim and help rewriting the paragraph witn actually being able to read the source.

Another issue might be that such an extensive coverage of a childhood episode might not all that appropriate for an encyclopedic article.--Kmhkmh (talk) 13:50, 20 November 2014 (UTC)

The quote in question is very long and includes many details of conversations and school schedules. It is not encyclopedic. Perhaps the optimal resolution is to summarize this episode in Plemelj's life in a couple of sentences. Mgnbar (talk) 13:47, 20 November 2014 (UTC)

Shortening the section seems appropriate to me. Do you have access to the source and can you read it by any chance?--Kmhkmh (talk) 13:51, 20 November 2014 (UTC)

The quote was probably added by User:XJaM, who might be able to help. r.e.b. (talk) 18:23, 20 November 2014 (UTC)

I'm so grateful for all of your responses. :) Projects do not always pitch in like this. I have now asked for User:XJaM's help. Whether or not he added it, he is familiar with the subject area (having edited the article) and might be able to help. :) Summarizing it would suit fine if the verifiability of the content is not suspect. --Moonriddengirl ^(talk) 12:20, 21 November 2014 (UTC)

In the absence of any other action on this, I've now gone ahead and removed the quote. But I see no reason why the constructions and accompanying diagrams should not be restored to the page if anyone has the skills and inclination to do that. Thanks to all who responded above. Justlettersandnumbers (talk) 23:48, 1 December 2014 (UTC)

"Notability" of Stirling polynomials

The "notability" of the topic of the new article titled Stirling polynomials is being questioned. Would perhaps a few more references settle that? Michael Hardy (talk) 23:25, 1 December 2014 (UTC)

Like most of that user's edits, none of the identities appearing in the article appear in the cited source. S?awomir Bia?y (talk) 23:43, 1 December 2014 (UTC)

To clarify my tagging: the article contains not even the most basic statement of why one should find these objects interesting, and this is why I tagged it. (I also think the "context" tag should be put back, but evidently User:Michael Hardy thinks the two sentence lead I wrote is sufficient on this front :).) --JBL (talk) 00:11, 2 December 2014 (UTC)

Draft:Gaussian process latent variable models

Hello, mathematics experts! Should Draft:Gaussian process latent variable models be published? --Cerebellum (talk) 07:25, 3 December 2014 (UTC)

This is not in my field. However, it strikes me as someone taking a well-known idea, slapping a new name on it and then trying to claim credit for it. JRSpriggs (talk) 16:31, 3 December 2014 (UTC)

User:Brirush Sectionifying

Over the last couple of weeks, since at least 22 Nov, User:Brirush has been "Sectionifying" lots of articles, splitting the leads up into lots of sections leaving behind a diminished lead which often says practically nothing e.g. arithmetic topology, arithmetic combinatorics, topological combinatorics. I believe it might be a good idea to just wholesale revert all the articles that have been sectionified rather than trying to check each one individualy to see if any of the sectioning was justified. 2.97.23.254 (talk) 16:27, 1 December 2014 (UTC)

I have no problem with you reverting the edits, but make sure you don't revert ones like Nash-Moser theorem, cofunction and computable analysis where content was added, unless you dislike the content. The size of the edit should be a clue. I do not plan on doing the reverts myself, as I obviously find my edits useful, but I won't keep you from reverting them.Brirush (talk) 17:00, 1 December 2014 (UTC)

Other useful ones to avoid deleting: Adding reference to R (complexity), adding image to conformal equivalence, adding "see also" items to many articles, adding an image to convex body, expanding dimension theory significantly, etc. I hope you exercise some restraint in your reverts.Brirush (talk) 17:26, 1 December 2014 (UTC)

Just to give another perspective, I looked at some of Brirush's edits and they all look improvement to me. (The amount is such that as if someone is paying him to do it.) Ledes don't need to be long and in fact many Wikipedia articles can use "sectionifying". People, both creators of the pages and others, (by which I mean editors such as myself) tend to add materials and changes in the organizational structure tend to lag behind. He is just correcting this. -- Taku (talk) 18:41, 1 December 2014 (UTC)

Yes, I agree with Taku. This is part of the natural process of turning stubs into something better than stubs; it gives them more structure, making it easier to see where they should be expanded. Reverting would send the wrong message "no, we want our stubs to stay stubby". --David Eppstein (talk) 18:47, 1 December 2014 (UTC)

I can understand your point of view--generally we don't want to reduce the usefulness of leads by cutting them down to single sentences. The Manual of style doesn't provide a lot of guidance for this. WP:LEADLENGTH says only that leads should be one or two paragraphs for articles of less than 15K characters. Wikipedia:Manual of Style/Lead section#Stubs says that sectioning of a stub should occur at an article length of 400-500 words. Some of the articles that Brirush has been sectioning have been shorter than this. But short articles often fit on a single screen, so there isn't much added cognitive friction in sectioning even short articles. I've looked at some of his recent edits and they seem fine to me. My guess is that Brirush is working very hard to improve the class of the mid and high importance articles in this project, a laudable goal. Sectionfying is a cheap way to help an article progress from 'stub' to 'start' class. So I'd recommend looking at each article on a case by case basis and if the sectioning has truly harmed understanding, unsectionfy and discuss on the article's talk page. --Mark viking (talk) 21:32, 1 December 2014 (UTC)

I went through and did more work on these articles (arithmetic topology, arithmetic combinatorics, topological combinatorics). If you find any more that are especially bad, let me know.Brirush (talk)

I undid your topological combinatorics one, but less because sectionifying was wrong there (it's a good length to have sections added and move from stub to start) and more because the text you added to make the sections flow seemed to me to misunderstand the subject. --David Eppstein (talk) 18:49, 3 December 2014 (UTC)

Thank youBrirush (talk) 00:44, 4 December 2014 (UTC)

merger proposal

We have a new article titled Legendre's formula, whose topic is the same as that of an old article titled de Polignac's formula. I've put "merge" tags on them. If they are merged, we have the question of what the title should be. Michael Hardy (talk) 23:53, 5 December 2014 (UTC)

Exponential broken up

Hi,

The article exponential map has been split into two articles: exponential map (Lie theory) and exponential map (Riemannian geometry) per the consensus at the talkpage, the original page having become the disambiguation page. It remains to fix a large number of incoming links. I did fix the most, but there are some instances when I couldn't figure out the correct targets. It seems many of them should have not be linked to the exponential map (a concept in differential geometry) to begin with. It would be nice if other editors with necessary background can take care of them. -- Taku (talk) 03:38, 6 December 2014 (UTC)

Maths ratings

I noticed that all Top-Class articles are rated B-class or higher. Are they really all at this level? Or is this an artifact from earlier, less restrictive rating requirements? In fact, I noticed that the maths rating "matrix" at Wikipedia:WikiProject_Mathematics/Wikipedia_1.0 is almost lower triangular.76.98.76.147 (talk) 00:46, 7 December 2014 (UTC)

I've noticed the same thing, but I've attributed it to editors' greater interest in more important topics and the relatively small number of articles on those topics. Ozob (talk) 02:59, 7 December 2014 (UTC)

Factorial categories

We're having a discussion at Talk:Factorial#Categories that started out being about some recent edits changing the categorization of that one article, but I think may be broadening to cover the proper relationship between Category:Factorial and binomial topics and Category:Gamma and related functions and their articles. The participation of additional knowledgeable participants would be helpful. --David Eppstein (talk) 06:08, 7 December 2014 (UTC)

Launch of WikiProject Wikidata for research

Hi, this is to let you know that we've launched WikiProject Wikidata for research in order to stimulate a closer interaction between Wikidata and research, both on a technical and a community level. As a first activity, we are drafting a research proposal on the matter (cf. blog post). Your thoughts on and contributions to that would be most welcome! Thanks, -- Daniel Mietchen (talk) 02:15, 9 December 2014 (UTC)

Concerns over the lead at Fourier transform

An editor has expressed concern over the lead at Fourier transform. Comments are welcome at Talk:Fourier transform#?Lead. S?awomir Bia?y (talk) 13:04, 26 November 2014 (UTC)

Several editors have expressed concern about the FT lead. Grandma (talk) 14:43, 26 November 2014 (UTC)

Indeed, over the course of the years, editors have expressed many concerns about the lead. I am here referring to the discussion of the present form of the lead. Only one editor (you) has expressed concerns about that, and they have not been terribly constructive. S?awomir Bia?y (talk) 15:06, 26 November 2014 (UTC)

User:I'm your Grandma. is acting rather disruptively at the talk page now. I had refactored the section on periodic and transient phenomena, forking out a new section that concerned the lead as a whole. She has insisted on merging these two sections, which makes no sense (presumably out of some sense of ownership) since the section Talk:Fourier transform#Lead has nothing at all to do with transient and periodic phenomena. Anyway, I don't wish to get involved in an edit war on the talk page there, but editors here should be aware that Grandma seems to be deliberately trying to scuttle the attempt to gather outside input. S?awomir Bia?y (talk) 16:03, 26 November 2014 (UTC)

I've been reverting further edits to the discussion page there as vandalism. More eyes would be helpful though. S?awomir Bia?y (talk) 16:29, 26 November 2014 (UTC)

I also encourage other editors to take a look at the lead of Fourier transform! Sincerely, Grandma (talk) 18:01, 26 November 2014 (UTC)

I could use some help dealing with "Grandma"'s continued trolling at that discussion page. S?awomir Bia?y (talk) 08:41, 9 December 2014 (UTC)

Open Access Reader, tool to find missing academic citations

Hi, I'm working on a project to find academic citations missing from Wikipedia, which I think might be useful for this Wikiproject. It's just a proof of concept right now, but if you have any ideas or feedback, that'd be really helpful at this early stage. Check it out: Open Access Reader.

EdSaperia (talk) 13:02, 9 December 2014 (UTC)

Waring's prime number conjecture

SuggestBot recently pointed me to the article linked above. It's extremely stubby (though better than the useless mathworld article it links), but before I work on it I wanted to check that I'm not missing anything obvious. The statement is just a weakening of the weak Goldbach conjecture, right? And as such, it follows from last year's papers by Helfgott (are they accepted to be correct?). Does anyone know of sources actually discussing this conjecture independently of weak Goldbach? Perhaps I will just merge and redirect it there.... Any thoughts welcome. --JBL (talk) 04:38, 10 December 2014 (UTC)

I have no idea about Helfgott but I'd support a merge to Goldbach's weak conjecture which is much more complete and as you say appears to be on almost the same problem. The main thing I'd want to find out before merging (so it could be included) is: why Waring? How did his name come to be associated with this? --David Eppstein (talk) 04:47, 10 December 2014 (UTC)

This is a particularly good question because the one reference in the article doesn't mention Waring. A quick internet search is not instructive. --JBL (talk) 04:58, 10 December 2014 (UTC)

Equilateral hexagon

In Equilateral pentagon it is available to calculate the values of three of the internal angles as a function of the values of the other two angles. Then is it available to calculate the values of three of the internal angles in Equilateral hexagon when I know the other three angles? --Eric4266 (talk) 11:09, 11 December 2014 (UTC)

If three adjacent angles of an equilateral hexagon are known, then that determines the distances between the other three vertices. There will then be two possible locations for the middle one of those vertices. In other words, there will be two solutions for the other three angles (with a degenerate special case when you have a straight angle). JRSpriggs (talk) 16:46, 11 December 2014 (UTC)

Deletion of Fork (topology)

Deletion of Fork (topology) has been proposed. Michael Hardy (talk) 18:55, 11 December 2014 (UTC)

Why no standard Wikiproject tag?

Why don't you use a standard Wikiproject tag? Why should this one Wikiproject be different than every single other one? This makes things more difficult for new page patrollers and the like. Oiyarbepsy (talk) 07:16, 11 December 2014 (UTC)

You mean, why is our standard Wikiproject tag called {{maths rating}} and not something else more...standard? History and inertia, I assume. But also, if you look at the should-not-be-used {{WikiProject Mathematics}} you will see another reason: because it is (or at least at some point was) the consensus of the project that indiscriminately tagging articles by project without also rating them is useless -- we have a bot-maintained list of articles that does a better job of identifying project-related articles than the banners do. As for new-page patrolling, see Wikipedia:WikiProject Mathematics/Current activity. --David Eppstein (talk) 07:24, 11 December 2014 (UTC)

Well, as long as the bot alerts you to new articles. I place the Wikiproject tags on all new articles I encounter so the WikiProjects who know the subject will see that there's a new article, but if your bot handles it, it's fine. Oiyarbepsy (talk) 07:30, 11 December 2014 (UTC)

The bot can miss things, mostly when they're not appropriately categorized. (If the category is added later, the bot will treat the article as new.) So catching and fixing those errors is definitely helpful. --David Eppstein (talk) 07:38, 11 December 2014 (UTC)

One qualm I've had about that bot is that its maintenance is wholly the work of one person rather than a crowd-sourced thing. If anything happens to him, the Universe will collapse (or at least those who follow our "current activities" page will no longer be able to do so). Michael Hardy (talk) 18:58, 11 December 2014 (UTC)

\not in MathJax puts the slash in the wrong place

With MathJax as my preferred rendering style (in Chrome on OS X), anomalous cancellation does not appear correctly: the slashes are placed near the digits they are supposed to be through. I.e. $\not {3}$ (<math>\not{3}</math>) renders as "/3" rather than as a slashed three. With the new MathML/SVG rendering it looks ok, so this is just MathJax. This does not happen when I use MathJax on web sites that I control, with the script from http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML, so I'm guessing it must be something Wikipedia is doing differently than the standard MathJax that screws it up, or possibly a bug in an older version of MathJax that's being used here. Anyone here have any idea what the problem is, how to communicate the existence of the problem to the people who maintain Wikipedia's MathJax interface, and how to persuade them to actually fix it? And/or, whether there's some way of working around this that still renders correctly in the other styles? --David Eppstein (talk) 23:50, 6 December 2014 (UTC)

Presumably here https://www.mediawiki.org/wiki/Extension_talk:Math? I wonder whether we are going to use mathjax or mathml. (For me the "mathml" option works the best.) -- Taku (talk) 03:46, 7 December 2014 (UTC)

Thanks for the suggestion; I left a pointer there to the discussion here. --David Eppstein (talk) 05:16, 7 December 2014 (UTC)

It curiously only fails with numbers

\not 3

and works with letters

\not B

. Looking at the generated code

3

there is a padding-left on the three which shifts it right. My guess is that this is a MathJax bug which has been fixed in the latest version but not version of MathJax we use.--Salix alba (talk): 07:44, 7 December 2014 (UTC)

An experiment:

a\not \in A\,

Michael Hardy (talk) 18:59, 11 December 2014 (UTC)

Strange notation in Proof that ? is irrational

I'm a bit rushed or I would try to figure out what _ought_ to appear where this appears in Proof_that_?_is_irrational#Hermite.27s_proof:

\overbrace {\left.\int _{0}^{1}(1-z^{2})^{n+1}{\frac {\sin(xz)}{x}}\right|_{z=0}^{z=1}} ^{=\,0}

Michael Hardy (talk) 19:40, 12 December 2014 (UTC)

I would assume that it's merely stating that that part of the formula is equal to zero and its removal leads to the simplification in the next line. No? --David Eppstein (talk) 20:17, 12 December 2014 (UTC)

Perhaps this is obvious, but there shouldn't be the integral sign (it's a boundary term after integration by parts.) . -- Taku (talk)

Oh, you mean that aspect of the notation: the fact that it has both an integral sign and a vertical bar, and no d? Yes, I think including the integral sign is a mistake. --David Eppstein (talk) 21:52, 12 December 2014 (UTC)

OK, now I've looked at it while not distracted by pressing things, and I've made the obvious correction. Michael Hardy (talk) 23:55, 12 December 2014 (UTC)

Israel Gelfand's Shapiro companions

Are Ilya Piatetski-Shapiro, coauthor of

Gelfand, I. M.; Graev, M. I.; Pyatetskii-Shapiro, I. I. (1969), Representation theory and automorphic functions, Academic Press, ISBN 0-12-279506-7

and Z. Ya Shapiro, coauthor of

Gelfand, I.M.; Minlos, R.A.; Shapiro, Z. Ya. (1963), Representations of the Rotation and Lorentz Groups and their Applications, New York: Pergamon Press

the same person? YohanN7 (talk) 08:03, 12 December 2014 (UTC)

No. According to MathSciNet, Ilya Piatetski-Shapiro has MR Author ID 139240, while Z. Ya Shapiro has MR Author ID 264360. Boris Tsirelson (talk) 06:45, 13 December 2014 (UTC)

Thank you. I thought maybe something had gotten lost in translations, since the subjects are closely related and were some of Gelfand's main interests at that time. (Next time I'll know where to look.) YohanN7 (talk) 07:44, 13 December 2014 (UTC)

I understand your doubt. But MathSciNet usually knows who is who. Boris Tsirelson (talk) 09:25, 13 December 2014 (UTC)

Euclidean algorithm

I have nominated Euclidean algorithm for a featured article review here. Please join the discussion on whether this article meets featured article criteria. Articles are typically reviewed for two weeks. If substantial concerns are not addressed during the review period, the article will be moved to the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Delist" the article's featured status. The instructions for the review process are here. -- Preceding unsigned comment added by ?DrKiernan (talk o contribs)

Seems like more anti-intellectualism from our friends in the wider Wikipedia community (anyone remember the ridiculous affair that the mathematical works of Alexander Grothendieck should be made accessible to laymen?) Now we are told that the article on the Euclidean algorithm should be made understandable to 10 year old children! S?awomir Bia?y (talk) 13:53, 6 December 2014 (UTC)

I think commenting on this nomination is worthwhile. Explaining and promoting mathematics to the widest community possible is important. More generally, Wikiarticles can often be structured so that there is something in them for general public as well as, when necessary, something in them for the expert. My thoughts, sincerely, Grandma (talk) 14:27, 6 December 2014 (UTC)

It's not a particularly good article. Anyone reading the whole thing risks to die from boredom. YohanN7 (talk) 14:54, 6 December 2014 (UTC)

Parts of it are boring to me as well. Perhaps not the best article to nominate? Or, maybe because it needs work, it would benefit from the scrutiny that comes with nomination? Grandma (talk) 15:07, 6 December 2014 (UTC)

Why waste time on an article that is already (undeservedly) FA-class? Yes, surely there must be other better suited. But I can't think of a single math article that is very likely to appear as a featured article (except articles about mathematicians). YohanN7 (talk) 15:26, 6 December 2014 (UTC)

I agree, the article can be improved. Nothing about the FA designation implies that the article is perfect. But the reasons for nominating it for review are thoroughly idiotic (an easily Googled fact tag, and a belief that the article should be accessible to 10 year olds). A review can be constructive, with thoughtful comments that lead to real improvements. But that didn't happen here. S?awomir Bia?y (talk) 19:00, 6 December 2014 (UTC)

Can we please keep the rhetoric conducive to teamwork? Thank you, Grandma (talk) 19:29, 6 December 2014 (UTC)

Grandma, I'm not sure what you hope to accomplish by your continued trolling, but I'm pretty sure "teamwork" is not high on the list. S?awomir Bia?y (talk) 19:47, 6 December 2014 (UTC)

Is there any reason to limit the inputs to two integers? I would think that one could start with any finite number of real numbers. Take their absolute values. Sort by size. Remove zero and any duplicates. Then begin a loop where you replace the largest number by the difference between the largest and the second largest and then resort and remove duplicates (if any). It terminates when there is only one number left (the GCD). No guarantees that it will terminate. JRSpriggs (talk) 10:17, 7 December 2014 (UTC)

The termination is almost exactly the definition of commensurable. This algorithm is not new, but it is slower than computing first the GCD of the two smallest entries, and then iterate (slower because of more operations involving two large integers).

To S?awomir Bia?y: I have not seen anywhere that "we are told that the article on the Euclidean algorithm should be made understandable to 10 year old children". However Euclidean algorithm is one of the rare important mathematical results that can been told to 10 year old children: It suffices to known long division to introduce it in the modern form using Euclidean division, and this is not even needed for the version by subtractions, which requires only to understand what is a divisor. The concept of GCD is not even required as a background, as Euclidean algorithm is the most elementary way to define GCD's and prove their existence (The set of common divisors is not changed when running the algorithm, and at the end, one gets the set of all divisors of the single remaining integer). It is a pity that the article is written in a style which makes elementary notions unnecessarily obscure for the layman. D.Lazard (talk) 11:38, 7 December 2014 (UTC)

Dr. Lazard, I do not see the problem with the style of the article that others are complaining about. This is not to say that this or that could not be rewritten in a different style, but I don't see any problems with the style that obviously need fixing, especially not to the extent that the article deserves to be dragged to FA review. Making the article accessible to a 10 year old, for whom even a capacity for reading at an advanced level is rather unlikely, is an unreasonable standard for any encyclopedia article, let alone one about a mathematical algorithm. I am aware that some young persons may learn this algorithm from textbooks which are written for one of such a reading and mathematical level, but I highly doubt that an encyclopedia article would benefit from being rewritten in such a style. There is a project "simple Wikipedia" that is more appropriate for such an undertaking. S?awomir Bia?y (talk) 15:26, 7 December 2014 (UTC)

S?awomir Bia?y, where was "understandable to 10 year old children" first brought up with respect to this Euclidean article? Or is this your interpretation of what is expected? Grandma (talk) 16:11, 7 December 2014 (UTC)

[52] S?awomir Bia?y (talk) 16:26, 7 December 2014 (UTC)

And that is not the same as saying that "the Euclidean algorithm should be made understandable to 10 year old children". Some material in the article should, yes, be accessible to the typical reader, and some material can be there for the expert. Grandma (talk) 16:31, 7 December 2014 (UTC)

"Grandma", for someone who pays lip service to the idea of "teamwork", you have almost nothing to add to a productive discussion. The single "fact" tag for which the article was brought to FAR has been fixed (by me). Apart from some vague statement that the article should be more accessible (the only target anyone has identified is a 10 year old, a clearly ridiculous standard). If no one actally has anything concerte to add, I propose that we close the FAR as resolved. S?awomir Bia?y (talk) 16:38, 7 December 2014 (UTC)

I oppose to close the FAR. The article is full of unresolved issues. Here are some of the main ones.

Before my today edit, the article did not mention one of the most important applications (important, at least, by the computer time devoted to it), the reduction of fractions. I have added it in the lead, but it deserves a section.
Section "Bezout's identity" presents a method for computing it. I do not know if it is WP:OR, but I am sure that nobody uses it, as extended Euclidean algorithm is much more efficient and easier to use.
In the applications, the distinction is unclear between the applications of Euclidean algorithm and those of extended Euclidean algorithm. Extended Euclidean algorithm is introduced only after using it several times (such as in "Bézout's identity" section).
The section on polynomial Euclidean algorithm is very poor (compare with sections "Univariate polynomials with coefficients in a field" and "Pseudo-remainder sequences" of Polynomial greatest common divisor. It is not even said that polynomial Euclidean algorithm is fundamental for testing multiple roots and polynomial factorization. Undue weight is given to Sturm chains, that are not an application of Euclidean algorithm, but a variant of it (this is not said).
The section "Generalizations to other mathematical structures" contains a confusing description of Gröbner bases. It says that it is a Generalization of Euclidean algorithm, which is historically wrong, as the connection between them has been discovered 7 years after the introduction of Gröbner bases. The important fact is not even given, namely that the polynomial Euclidean algorithm and Gaussian elimination are two special cases of Gröbner basis computations.

This only some of the many issues of this article. Considering them as minor would give a bad opinion of our community to external people. D.Lazard (talk) 19:17, 7 December 2014 (UTC)

These comments should really appear on Wikipedia:Featured article review/Euclidean algorithm/archive1 so it becomes part of the review process.--Salix alba (talk): 23:15, 7 December 2014 (UTC)

I mean no offense, but this is not a particularly "exciting" article to read. In a sense, it is irrelevant whether the article is understandable to 10-year-old boys and girls since they will not be reading it in the first place. In fact, it is not clear to me what the target audience of the article is. Wikipedia articles are meant for college-educated or college-being-educated "adults"-those who already known gcd. Thus, in principle, it is not necessary to write them like textbooks that are used in elementary schools. But we "could" choose to make the article accessible to children, but then as pointed out above, it's much better to start without gcd; the algorithm is simpler than the concept (I suppose.)

If the article is meant for more sophisticated readers, then it still fails them. I'm thinking of a para from the article like this one (excuse me for a long quote):

The fundamental theorem of arithmetic applies to any Euclidean domain: Any number from a Euclidean domain can be factored uniquely into irreducible elements. Any Euclidean domain is a unique factorization domain (UFD), although the converse is not true. The Euclidean domains and the UFD's are subclasses of the GCD domains, domains in which a greatest common divisor of two numbers always exists. In other words, a greatest common divisor may exist (for all pairs of elements in a domain), although it may not be possible to find it using a Euclidean algorithm. A Euclidean domain is always a principal ideal domain (PID), an integral domain in which every ideal is a principal ideal. Again, the converse is not true: not every PID is a Euclidean domain.

Again, who would be reading this? The majority of non-math major students need not learn about the distinction between lovely ring-alphabets: UFD, PID, GCD, etc. And why is this in the article "Euclidean algorithm"? Especially, the mention of GCD domains is problematic; it's only interesting to students in "ring theory". It's quite remarkable that the existence of GCD can guarantee that the domain is an integrally closed domain. But there is no need for a student to start to think about GCD domains before he (usually not she) learns about integrally closed domains.

In short, it's not clear to me what reader would enjoy reading this article. -- Taku (talk) 22:02, 7 December 2014 (UTC)

In the UK we start talking about GCD in Key Stage 3, 11 - 14 years old. I would say there is a good number of children in that age group who would try to read this article. So there is a good case for targeting some of the article at that age group. I think it does that quite well. The article much also pass WP:FACR in particular 1b: comprehensive. This means it must include advanced material which such children will not be able to follow.--Salix alba (talk): 23:10, 7 December 2014 (UTC)

A bit off topic but its not just the wikipeidia community which has problems with maths. Nature has just rejected an Obit of Alexander Grothendieck by David Mumford and John Tate for being too technical.[53] --Salix alba (talk): 09:41, 16 December 2014 (UTC)

Intriguing: Tsirelson's rogue edits

According to Daqu,

Tsirelson is known for undoing other people's Wikiedia edits without explaining his reasons for doing so.

If you are intrigued, see this edit, with the summary "Added fact about Tsirelson's rogue edits of Wikipedia". See also here and here. --Boris Tsirelson (talk) 09:53, 16 December 2014 (UTC)

Intriguing indeed. @Daqu: surely you must have an explanation. I see no reverts of your edits unless you have edited as an ip. YohanN7 (talk) 10:53, 16 December 2014 (UTC)

It surely must be intended as a joke. Unfortunately, on the internet the line between humor and psychopathic behavior is often not very clear. S?awomir Bia?y (talk) 12:10, 16 December 2014 (UTC)

Notification of merger proposal

I propose to merge Stern-Brocot tree and Calkin-Wilf tree, as they appear to be exactly the same tree. I have no opinion for the name of the merged article. I notify this project because of the low number of readers and watchers for both pages. I have opened the discussion at Talk:Stern-Brocot tree#Merger proposal. D.Lazard (talk) 18:00, 16 December 2014 (UTC)

Discussion of the merits of this proposal can continue at that talk page, but I would like to point out a factual error in your announcement here: these are not the same tree as each other. For instance, the children of 1/2 are different. --David Eppstein (talk) 18:33, 16 December 2014 (UTC)

Notification of Request for comments

I have opened a request for comments at Talk:Euclidean algorithm#Request for comments. D.Lazard (talk) 11:39, 19 December 2014 (UTC)

Two drafts for review

These two drafts were submitted today and look promising:

User:Cleary83/sandbox (matrix regularization)
User:Kjross/sandbox (loss function surrogates for classification)

Math topics aren't my forte on Wikipedia, so I'm posting these here if anyone has any comments or wants to review them. Thanks, ~SuperHamster Talk Contribs 06:12, 21 December 2014 (UTC)

Frame (signal processing)

Should the new article titled Frame (signal processing) be merged into Frame of a vector space? Michael Hardy (talk) 21:15, 21 December 2014 (UTC)

A merge does seem appropriate. For what it's worth, I think the new article frame (signal processing) is written in a much clearer style than frame of a vector space. S?awomir Bia?y (talk) 15:00, 26 December 2014 (UTC)

On a related note, Frame (linear algebra) probably should be a disambig page; in fact, it's already written that way. -- Taku (talk) 23:08, 26 December 2014 (UTC)

Recent activity at Talk:Quantum Mechanics

Hi!

There has been a storm of activity the past week (by few authors). I think we need more to chip in since the article is (ought to be) pretty vital in physics (and mathematics by extension to today's math-infested QM applications). The interested could perhaps have a look at Talk:Quantum mechanics#1920s quantum mechanics not obsolete. YohanN7 (talk) 11:59, 29 December 2014 (UTC)

WikiCup 2015

Hi there; this is just a quick note to let you all know that the 2015 WikiCup will begin on January 1st. The WikiCup is an annual competition to encourage high-quality contributions to Wikipedia by adding a little friendly competition to editing. At the time of writing, more than fifty users have signed up to take part in the competition; interested parties, no matter their level of experience or their editing interests, are warmly invited to sign up. Questions are welcome on the WikiCup talk page. Thanks! Miyagawa (talk) 21:53, 29 December 2014 (UTC)

Navier - Stokes Millennium Prize Problem. Alternative Solution

The above shows that our old friend Continuum-paradoxes (talk · contribs · deleted contribs · logs · edit filter log · block user · block log) is back (and apparently editing under various IPs). He is no longer limiting his contributions to discussion pages, so it might be good for project participants to keep an eye on Navier-Stokes related articles (and other articles that this crank might attempt to push his OR). S?awomir Bia?y (talk) 01:52, 30 December 2014 (UTC)

Source of the article : Wikipedia

Kamis, 03 Mei 2018

Wikipedia talk:WikiProject Mathematics/Archive2014

Jan 2014

Video Wikipedia talk:WikiProject Mathematics/Archive2014

Wikipedia:Articles for deletion/Gilles Baroin

Maps Wikipedia talk:WikiProject Mathematics/Archive2014

Epsilon zero

Subtraction methods

Consistency in pluralization?

Binary notation

Question regarding well-defined vs. completely determined

How to handle CMP index in cite template

TeX rendering on Firefox

AfC submission

Brouwer fixed-point theorem

Poisson point process

Invitation to User Study

New functional analysis template added to many articles

Cocycle

Topology good aeticle review

Quotition

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Partial derivative : how to read and how to compute it ?

AfC submission

Wikipedia talk:Articles for creation/Chi-Squared Divergence

Hamilton Mathematics Institute

List of algebras

Thoughts on this wikiproject

Zeta(-1)

AfC submission

Feedback request: VisualEditor special character inserter

Cone

Distance from a point to a line and Perpendicular distance

Pollock's conjecture(s)

spelling of "l'Hopital's rule"

AfC submission (Deep learning)

Mathematics and art

Topology of uniform convergence

Wikipedia talk:Articles for creation/Phan Sequence

Feb 2014

Intersection

Wikipedia talk:Articles for creation/Stability of Boolean networks

"Octagonal"

AfC submission

Cyclic sieving

EOM links

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Displayed equations are centered?

Wikipedia talk:Articles for creation/Ignatov's theorem

Numbering equations

AfC submission

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Decoupling (mathematical analysis)

Suborder into order?

Summation

{{val2}}

How to display math with the next release

Changes of Math 2.0

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Performance of cache fixed 15 Feb 2014

List of mathematical symbols as TeX codes

user Wachipichay

Euler's identity?

Eigenvalues and eigenvectors - Illustration

Popular pages tool update

List of unsolved problems in Cryptography

Global analysis?

Requested articles/Mathematics/Logic?

Upright versus italic d

AfC submission no 2

K(n,n) equation

Miss-matched <sub> and <sup> tags

Total free access to Royal Society History of Science journals for 2 days on March 4th and 5th !!!

Fibred category -> Fibered category

Four-paragraph leads -- a WP:RfC on the matter

Help needed with eight links to Index (mathematics)

Mar 2014

"Numerical cipher"

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