# Wikipedia talk:WikiProject Mathematics/Archive/2013/Oct

Template:Wikipedia talk:WikiProject Mathematics/archivelist

## Context-setting in queueing theory articles

I find it alleged that nearly all of our queueing theory articles begin with "In queueing theory, . . .".

That is bad. It makes no attempt to inform the lay reader that mathematics is what the article is about.

The following are appropriate:

- In algebra,
- In arithmetic,
- In geometry,
- In number theory,
- In calculus,
- In advanced calculus,
- In mathematics,
- In probability theory,
- In mathematical logic,

The following are NOT appropriate:

- In topology,
- In category theory,
- In queueing theory,

The lay reader has not heard of those things. (As an undergraduate, I was surprised to find that some literate people hadn't heard of topology. But it's true.)

If an article is titled "Mathematical induction" or "Fundamental theorem of algebra" or the like, then the title alone obviates the need for such an initial context-setting phrase.

So, shall we fix all our queueing theory articles? Michael Hardy (talk) 01:50, 28 September 2013 (UTC)

- I'm not convinced that category theory is considered part of mathematics; many category theorists seem to think that mathematics is part of category theory. I'm not sure what to suggest as an alternative. — Arthur Rubin (talk) 02:09, 30 September 2013 (UTC)
- Wow... What about a category theory faculty, with a school of math inside it? Boris Tsirelson (talk) 06:17, 30 September 2013 (UTC)
- Surely this is because category theory can be used as a foundation for mathematics; see Lawvere's elementary theory of the category of sets. Ozob (talk) 14:12, 30 September 2013 (UTC)

- But, then, I'm not sure what category theory is, exactly, so I tend to agree that
*some*alternative is necessary. — Arthur Rubin (talk) 02:23, 30 September 2013 (UTC)

- I'm not convinced that category theory is considered part of mathematics; many category theorists seem to think that mathematics is part of category theory. I'm not sure what to suggest as an alternative. — Arthur Rubin (talk) 02:09, 30 September 2013 (UTC)

- I agree that it is best to put first-sentence context in plain terms. I have been doing this as I encounter math articles without good context. Topology is an especially good example, as topology, in the form of Geospatial topology, means something different to a cartographer than to a mathematician. How best to do this? I've seen a two level hierarchy used in some articles:
- * In topology, a branch of mathematics, a
**first-countable space**is .... - * In category theory, a discipline in abstract nonsense, .... (just joking)
- or
- * In mathematics, specifically general topology and metric topology, a
**compact space**is ... - Although a bit more verbose, I like that the hierarchy both lets the general reader know that this is math and the more advanced reader the specific context. --Mark viking (talk) 03:38, 30 September 2013 (UTC)
- So should one say queuing theory part of mathematics or operations research or probability or statistics or applied mathematics or what? Dmcq (talk) 14:08, 30 September 2013 (UTC)
- Actually the boilerplate for queueing theory articles is "In queueing theory, a discipline within the mathematical theory of probability," which I believe already provides clear context. The queueing theory article itself starts "Queueing theory is the mathematical study of waiting lines" which is also clear and proves that you don't always have to use the boilerplate. --RDBury (talk) 16:18, 2 October 2013 (UTC)

I think the emphasis on boilerplate in place of creative solutions for context-setting (as promoted by e.g. Hardy) has been extremely harmful to the quality of our prose. It leads to atrocities like "In mathematics, in the field of additive combinatorics, Kneser's theorem, named after Martin Kneser, is a statement about set addition in finite groups." In this encyclopedia, we are in the English language, not German, with its tendency to many clauses at the start place and to the verbs to the end hold back, writing. Stilted prose makes for a difficult reading experience. Context is necessary but not at the expense of readability. —David Eppstein (talk) 18:02, 2 October 2013 (UTC)

- I think your German syntax is imperfect. In German, unlike English, one never splits infinitives. What would Mark Twain think? Michael Hardy (talk) 18:35, 6 October 2013 (UTC)

- I have also noticed that there is a tendency to cram all kinds of information into the very first sentence. This is especially the case for eponyms. There is a widespread belief that the namesake must be identified immediately, but this usually clashes with any kind of context-setting that the first sentence is supposed to provide. Sławomir Biały (talk) 18:50, 2 October 2013 (UTC)
- MOS:CONTEXTLINK indicates
*In an article about a technical or jargon term, the opening sentence or paragraph should normally contain a link to the field of study that the term comes from*, but doesn't specify the grammatical format. So adding contextual links is policy, but the links do not have to be in initial clauses in the first sentence. --Mark viking (talk) 21:14, 2 October 2013 (UTC)

I'd say eponyms should usually be identified in the first paragraph, and often, but not always, in the first sentence. Michael Hardy (talk) 18:36, 6 October 2013 (UTC)

- I think the eponym and the specific subarea of mathematics to which the subject belongs should be in the first paragraph, but usually *not* in the first sentence. This secondary information distracts from the main purpose of the first sentence, which is to state what the subject actually is. And the insistence on cramming secondary information like this into the main sentence, while still keeping the definition of the subject, has led to run-on sentences and much awkward prose. This is harmful to readability and makes our articles look more technical than they are, when what we should be trying to do is make the writing as clear and simple as possible so that the only obstacle to understanding them is the difficulty of the mathematics itself. —David Eppstein (talk) 19:17, 6 October 2013 (UTC)

## Learning Entropy

This article recently got accepted by WP:WikiProject Articles for creation

It looks more than a bit dodgy to me. The four refs that discuss the concept all share a common author; what's presented seems very vague; and I do find this non-Shannon entropy pretty dubious and of questionable notability, unless some pretty strong evidence is forthcoming for its significance (which, at least in the article, it seems to me so far hasn't been).

Am I being over-sensitive and over-suspicious here, or do others agree? Second opinions would be appreciated. Jheald (talk) 23:16, 6 October 2013 (UTC)

- The article doesn't seem to have any content. I wouldn't be surprised if the concept is non-notable. Ozob (talk) 01:04, 7 October 2013 (UTC)

- I tried reading through the first reference and confess it seemed a buzzword-compliant word salad of topics in statistics, dynamical systems, and signal processing. I gather it is supposed to be a new method for change point detection, but don't see the relation to the traditional concept of Shannon entropy. Fractals are mentioned, so perhaps some variant of Tsallis entropy? At any rate, most refs are from a single group and I don't see any secondary refs, so notability may be an issue. --Mark viking (talk) 01:17, 7 October 2013 (UTC)

- Off to AfD we go then. Jheald (talk) 08:12, 7 October 2013 (UTC)

## Feedback request regarding a list

I created Lists of unsolved problems in mathematics a while ago. Now I am no longer sure whether a particular one of the entries should be kept in the list or not. Do you think Unsolved Problems on Mathematics for the 21st Century fits into the scope of the list, or should it be removed? Thanks for any feedback. -- **Toshio** **Yamaguchi** 13:13, 7 October 2013 (UTC)

- I suggest that you create articles for the three red-links in your meta-list. If you are unable to create an article to resolve one of the links, then perhaps it should be removed. JRSpriggs (talk) 02:31, 8 October 2013 (UTC)

## Waghani's theorem

Hoax? Anna Frodesiak (talk) 13:46, 7 October 2013 (UTC)

- Possibly. I think the references need to be checked for their credibility. I have been unable to find a mention of the 1988
*An Introduction to Group Theory*reference via Google. A Google search for*"International Journal of Universal and Abstract Algebras"*finds only this Wikipedia article, so the second reference might also be non-existent. Same goes for*"Advances in Applied Abstract Algebra in Quantum Gravity"*. The last reference appears to be a personal blog. --**Toshio****Yamaguchi**14:31, 7 October 2013 (UTC)

- Also there are no credible Google hits for "Sheth algebra", which the theorem is supposedly about. Sławomir Biały (talk) 14:48, 7 October 2013 (UTC)
- The only title hit for "Sheth" in MathSciNet is Template:MR, which is about Hilbert spaces and appears unrelated to the paper. In particular, reference [2] does not appear to exist. I think it's a hoax. I've tried prodding it, but I expect the editor who created it to unprod it and force an AfD. —David Eppstein (talk) 16:14, 7 October 2013 (UTC)
- As predicted, the prod was removed. Now at AfD. Please participate. —David Eppstein (talk) 05:36, 8 October 2013 (UTC)
- Hi David Eppstein (talk), I removed the prod because it was causing problems with the formula. — Preceding unsigned comment added by 219.90.100.148 (talk) 12:31, 8 October 2013 (UTC)

- As predicted, the prod was removed. Now at AfD. Please participate. —David Eppstein (talk) 05:36, 8 October 2013 (UTC)

- The only title hit for "Sheth" in MathSciNet is Template:MR, which is about Hilbert spaces and appears unrelated to the paper. In particular, reference [2] does not appear to exist. I think it's a hoax. I've tried prodding it, but I expect the editor who created it to unprod it and force an AfD. —David Eppstein (talk) 16:14, 7 October 2013 (UTC)

## AfC submission

Could any of you have a look at this? Appreciated, FoCuSandLeArN (talk) 15:51, 10 October 2013 (UTC)

- I'm no expert at game theory, but it looks good to me. I've left a pointer at WT:ECON#Article for creation since I think this is more their style. Ozob (talk) 13:24, 11 October 2013 (UTC)
- I can't verify that the term is actually used (in spite of the references), but it is a concept of some interest. If I get a chance, I may look at it more closely. — Arthur Rubin (talk) 15:47, 11 October 2013 (UTC)

- There are copyright violations in the lead of the article, I noted this on the AfC submission page. so the whole article probably needs to be checked. As for the subject, Aggregative games have been around for decades and have been worked on by many different groups. There is a mean-field approach for these games that makes them computationally tractable even for large N and they've seen use in economic models. There is potential for a notable article on the subject. --Mark viking (talk) 17:31, 11 October 2013 (UTC)

- I think that aggregative games are
*not*a proper subset of general n-person games. Any n-person game can be encoded as an aggregative game. So this whole thing seems suspicious to me. JRSpriggs (talk) 05:47, 12 October 2013 (UTC)

- I think that aggregative games are

- Thanks a lot, people! Here's another one. Would you be interested in doing a weekly sweep? We get dozens of these a month. Cheers, FoCuSandLeArN (talk) 15:19, 14 October 2013 (UTC)
- If it has the same topic as an EoM article, it's certainly a valid topic for Wikipedia. That one looks like a quick yes. —David Eppstein (talk) 16:33, 14 October 2013 (UTC)
- The article looks like a close copy of the EoM article. As long as that is OK (not sure about copyright in this instance), it is a valid topic and the article looks like a fine stub. --Mark viking (talk) 17:21, 14 October 2013 (UTC)
- I think it's different enough not to be a problem. I don't see much close paraphrasing nor any copied text (not counting the equations, in which there isn't much to change), just an overall similarity in the choice of what information to present. —David Eppstein (talk) 17:42, 14 October 2013 (UTC)
- Looking at the article again, I agree the prose is different enough to not be considered a copyvio or a too-close paraphrasing. The article is good to go. --Mark viking (talk) 22:12, 14 October 2013 (UTC)

- I think it's different enough not to be a problem. I don't see much close paraphrasing nor any copied text (not counting the equations, in which there isn't much to change), just an overall similarity in the choice of what information to present. —David Eppstein (talk) 17:42, 14 October 2013 (UTC)

I wonder if people involved in that WikiProject _ever_ exercise any judgment about editing the title of the article rather than just going with whatever the draft has. If I write such a draft and call it "GirafFe", about animals with long necks living in African plains, will they approve it and move it to the article space with the title "GirafFe"? Someone moved the draft to Aggregative games. So I moved it from there to Aggregative game and fixed the link. I've seen lots of previous instances just as glaring. Michael Hardy (talk) 16:43, 14 October 2013 (UTC)

- Thanks for dong this. Not only did the closing AfC admin not exercise judgement, they ignored our comments on the article. I had to handle the copyvio separately, too. --Mark viking (talk) 10:28, 15 October 2013 (UTC)

- Just a few comments here. When I post a submission to an appropriate WikiProject, I expect the latter to go ahead and review the article given we lack the expertise to fairly do so ourselves. I did not approve that submission, and if you have any comments about it, please refer to the respective user's talk page. As for the naming, we try to do our best, but as I said, we are not mathematicians, doctors, geographers, biographers nor engineers, so when an article follows simple MOS standards, we feel safe enough to accept the article name as is, and in some instances do obviously change it. You can't expect us to please 100% of the technical encyclopaedia's audience, especially when the backlog is usually above 1000, even during the backlog drives. We are kind enough to notify you of several pertinent submissions, and that's one of the reasons we do so. Unfortunately almost none of our requests are answered by the majority of WikiProjects, so we have to make do. As I said before, ancarryd was hinted at by AfC after your aggressive post on the reviewers' talk page, if you'd like to see a better representation of your Project's interests, please come forward and dedicate some time to reviewing. I've selected another submission for you to start with. Kind regards, FoCuSandLeArN (talk) 14:08, 17 October 2013 (UTC)

- I'd like to thank you (and the rest of the AfC project) for diligently bringing relevant articles to the attention of the Wikiproject. Please don't think that your work is not appreciated just because certain editors can be a little prickly about MOS issues. Sławomir Biały (talk) 15:44, 17 October 2013 (UTC)

- I'd like to thank you as well. I think there is good synergy between our groups. Here is background on the particular issue. Both Michael and I posted comments on the article page between the AfC header and the lead--his about a suggested name change and mine about a copyvio in the lead. The closer approved the article, deleted the comments and did not fix the issues. I thought it odd and followed up with him. He was expecting the comments somewhere else. I then followed up with the author and we got the copyvio resolved. My irritation was at ignoring the existing AfC comments, but anyone can make mistakes. Guidance on where best to place comments is appreciated. Thanks, --Mark viking (talk) 18:30, 17 October 2013 (UTC)

I think there may be a structural issue in that AfC submissions are in talk name space and there is no obvious place to leave comments on them. So when these submissions are brought to the attention of this project, the discussion happens here, but then subsequent AfC reviewers may well not find it here. —David Eppstein (talk) 17:07, 17 October 2013 (UTC)

- You need to install the helper script: see WikiProject Articles for creation/Reviewing instructions. RockMagnetist (talk) 17:36, 17 October 2013 (UTC)
- Ok, but that does not contradict what I said about there being an *obvious* way to leave comments. —David Eppstein (talk) 18:02, 17 October 2013 (UTC)
- I agree it's not obvious. Such a big AfC banner and such a tiny link to reviewer instructions. RockMagnetist (talk) 18:27, 17 October 2013 (UTC)
- And even if you do manage to find the instructions link, most of it is aimed at how to make an actual decision on the submission. The parts about having a discussion first are treated as an afterthought in the "see also" section. —David Eppstein (talk) 18:34, 17 October 2013 (UTC)

- I agree it's not obvious. Such a big AfC banner and such a tiny link to reviewer instructions. RockMagnetist (talk) 18:27, 17 October 2013 (UTC)
- Do we really need to install and learn the AfC helper script just to add a comment to an AfC article? It seems a high bar to set for participation. I have used Template:Afc comment before, but didn't this time, as I thought it better to be consistent with the style of the other comments. --Mark viking (talk) 18:50, 17 October 2013 (UTC)
- Thank you for clearing this out. I'm glad we understand each other. AfC comments within the submission are intended for the submitter and/or future reviewers, unless the past reviewer added that particular article to his/her watchlist. The AfC comment template is a handy way of commenting without using the script (I recommend using the script for reviewing maths submissions if you're willing to participate). All other comments should be directed to the AfC talk page, where all reviewers discuss reviewing matters on a daily basis. I understand some problems have taken place because of this fragmented means of communication and will continue to do so given we often deal with very inexperienced submitters who get quite anxious. That's why we also advise using the Teahouse and the AfC Help desk for more urgent problems. We are constantly working towards being as clear and simple as possible (a tough task considering the inherent shortcomings regarding AfC as a concept), so we appreciate all of your input. Please come over and talk to us about all this, as I'm sure it will be a very positive experience. As for reviewing per se, here's yet another submission. Regards, FoCuSandLeArN (talk) 19:09, 17 October 2013 (UTC)

- Ok, but that does not contradict what I said about there being an *obvious* way to leave comments. —David Eppstein (talk) 18:02, 17 October 2013 (UTC)

Thanks for pointing to {{Afc comment}} — I didn't know about that one before and have just used it on the Brauner space submission, I hope correctly. —David Eppstein (talk) 19:55, 17 October 2013 (UTC)

## What tau deserves

The triannual discussion of tau is in full blast here: Talk:Tau_(2π)#Tau_deserves_its_own_article. Tkuvho (talk) 08:56, 15 October 2013 (UTC)

## Frame graph

What should be the fate of the new article titled Frame graph? Are there any results of interest that should be included in the article, rather than a mere definition? Is the topic worthy of an article? Michael Hardy (talk) 21:54, 15 October 2013 (UTC)

- There's some related material on orthonormal representations in our article Lovász number and in chapter 9 of Lovász' geometric graph theory book. However, I don't know of any relevant references for this meaning of the title phrase "frame graph": everything that I can find with that phrase uses it with a different meaning (not consistently with each other either). —David Eppstein (talk) 23:34, 15 October 2013 (UTC)
- Notable or not, there's not enough material at the moment for an article. What's there should have been added to Frame of a vector space. --RDBury (talk) 10:39, 18 October 2013 (UTC)
- I've tried prodding the article. —David Eppstein (talk) 18:23, 22 October 2013 (UTC)

- Notable or not, there's not enough material at the moment for an article. What's there should have been added to Frame of a vector space. --RDBury (talk) 10:39, 18 October 2013 (UTC)

## Level in mathematics rating

People often complain that mathematics articles are particularly difficult to understand because the experts writing the articles have a completely different level of understanding of the topic than the typical reader, who might be for example a high school student. Has the community considered including the level of the article in the mathematics assessment, i.e. whether an article is intended to be at for example high school, undergraduate, or graduate level? Isheden (talk) 06:21, 18 October 2013 (UTC)

- One difficulty is that different parts of the article have and should have different levels. For instance, I believe that we should try to write the first sentence of an article at least one level below its most technical parts. (in a rough system of levels like high school / general undergraduate / undergraduate specializing in mathematics / graduate coursework / research). —David Eppstein (talk) 06:34, 18 October 2013 (UTC)
- Sure, but a topic has a general level of difficulty that could be recorded somewhere. It's not a precise thing, but Stone–Čech compactification is going to come out more difficult than calculus, no matter how hard we work to make the introduction as gentle as possible.
- My question is more, what good would it do? The "ratings" are for editors, not readers. Who's going to see them, and how will they benefit from seeing them? --Trovatore (talk) 09:15, 18 October 2013 (UTC)
- Yes, the "ratings" would be a guide for editors what prerequisites that can be expected. The reader typically just stops reading without posting anything on the talk page if the article is not accessible. Isheden (talk) 10:00, 18 October 2013 (UTC)
- I'm not convinced that grading articles' difficulty makes a lot of sense. For example, chain rule starts out very gently, but by the end it mentions Banach spaces, semimartingales, and other advanced topics. Or, as another example, the basics of Fibonacci numbers can be explained even to young children, but understanding the divisibility of Fibonacci numbers by primes requires some knowledge of quadratic residues in prime fields. Deep (even not-so-deep) subjects can be explained and understood on many levels, so we should expect our articles to have parts of inconsistent difficulty. Ozob (talk) 13:35, 18 October 2013 (UTC)
- I agree with Ozob. More, it is rather common that rather elementary notions need deeper mathematics that are not easy to explain elementarily. I have encountered this problem with Critical point (mathematics): before my edits, the lead were confusing between the critical points of a function and the critical points of the graph. To resolve this confusion, I had to understand that the critical points of the graph are, in fact, the critical points of the projection (of the curve) parallel to one of the axes. With this remark both definitions agree, but the latter needs the notion of differentiable map between manifolds. Nevertheless, the notion of critical point of a projection must appear in the lead, because it is fundamental for elementary sketching of algebraic curves and also for explaining the notion of stationary point in the orbit of a planet. I have tried to resolve this, but the article deserves further editing. D.Lazard (talk) 14:43, 18 October 2013 (UTC)
- Let's take Critical point (mathematics) as example: Shouldn't at least the first part of the article be accessible to a student taking a first course in calculus? I think there should be a few examples and a simple discussion of the first derivative test without fancy notation like in the beginning. Why are there two articles Stationary point and Critical point (mathematics), respectively? Is one of them intended for a lower level? Isheden (talk) 16:42, 18 October 2013 (UTC)
- Stationary point and critical point are different, though related concepts. For example a point where the derivative is undefined is a critical point but not a stationary point. The case for a merge could be made though. On your wider point, that the start of an article should be as accessible as possible, that's already a guideline, though perhaps not already followed. I'm not sure how having a difficulty rating would would help to enforce that; it would better to add "too technical" tag to the article if it needs to be reworded for a wider audience. I think the difficulty rating idea, or at least a variation of it, has been raised before, and it seems tempting. But even if you could get around the issue that articles don't lend themselves easily to a single rating, I think a bigger issue is whether the possible benefits outweigh the additional time and effort it would take to create and maintain these ratings. Readers already know whether they can understand an article and editors, the good ones at least, should know at what level to write a section without having to read a rating on the talk page. WP has a write once, ready many data model so it's really readers who should be the primary concern. Is there there a scenario you have in mind where readers would save time by checking a difficulty rating over not checking? Keep in mind that the first line of an article is supposed to establish context, so someone who sees the name of an unfamiliar subject there won't be spending a lot of time on the article to start with. --RDBury (talk) 09:04, 20 October 2013 (UTC)
- As far as I know, in the main stream of mathematics, "critical point" is defined only for differential functions and thus "critical point" and "stationary point" are exactly the same thing. I believe that the assertion "a point where the derivative is undefined is a critical point" comes from a confusion between the notion of critical point of a function and the notion of critical point of a curve for the projection on the
*x*-axis. In fact, for the function (half unit circle), the derivative is not defined for*x*= ±1, and (-1, 0) and (1,0) are critical points of the projection of the circle on the*x*-axis); this does not implies that -1 and 1 are critical points of the function*f*. This confusion is rather common, and I have done it myself (see my self revert in the history of stationary point). *About a merge of critical point (mathematics) and stationary point*: I was tempted to do it, but I have renounced because the latter article is, in fact, devoted to the study of the possibles shapes at a stationary point of the graph of a function of a single variable, while the former should describe the main aspects of the notion in various branches of mathematics (it is yet almost a stub). Thus I am not convinced that a merge would improve WP.- D.Lazard (talk) 11:23, 20 October 2013 (UTC)
- (Apologies for getting further off topic...) The terminology seems to vary somewhat, for example Stewart defines a critical number as a point where the derivative is 0 or undefined. I'm not sure about mainstream mathematics but when I was teaching first semester calculus I probably included endpoints of the domain as well. Basically make the definition so that "extreme point => critical point" is always true. We also have Fermat's theorem (stationary points) and First derivative test which cover much of the same ground as the above two articles. --RDBury (talk) 22:56, 20 October 2013 (UTC)
- One more off-topic comment: If in main stream mathematics critical point and stationary point are exactly the same thing, then they should be covered in a single article, with one redirecting to the other. One possibility would be to redirect critical point (calculus) to stationary point. Another possibility is to expand the disambiguation page critical point. Currently only the use in calculus is mentioned there. Isheden (talk) 10:04, 21 October 2013 (UTC)

- As far as I know, in the main stream of mathematics, "critical point" is defined only for differential functions and thus "critical point" and "stationary point" are exactly the same thing. I believe that the assertion "a point where the derivative is undefined is a critical point" comes from a confusion between the notion of critical point of a function and the notion of critical point of a curve for the projection on the

- Stationary point and critical point are different, though related concepts. For example a point where the derivative is undefined is a critical point but not a stationary point. The case for a merge could be made though. On your wider point, that the start of an article should be as accessible as possible, that's already a guideline, though perhaps not already followed. I'm not sure how having a difficulty rating would would help to enforce that; it would better to add "too technical" tag to the article if it needs to be reworded for a wider audience. I think the difficulty rating idea, or at least a variation of it, has been raised before, and it seems tempting. But even if you could get around the issue that articles don't lend themselves easily to a single rating, I think a bigger issue is whether the possible benefits outweigh the additional time and effort it would take to create and maintain these ratings. Readers already know whether they can understand an article and editors, the good ones at least, should know at what level to write a section without having to read a rating on the talk page. WP has a write once, ready many data model so it's really readers who should be the primary concern. Is there there a scenario you have in mind where readers would save time by checking a difficulty rating over not checking? Keep in mind that the first line of an article is supposed to establish context, so someone who sees the name of an unfamiliar subject there won't be spending a lot of time on the article to start with. --RDBury (talk) 09:04, 20 October 2013 (UTC)

- Let's take Critical point (mathematics) as example: Shouldn't at least the first part of the article be accessible to a student taking a first course in calculus? I think there should be a few examples and a simple discussion of the first derivative test without fancy notation like in the beginning. Why are there two articles Stationary point and Critical point (mathematics), respectively? Is one of them intended for a lower level? Isheden (talk) 16:42, 18 October 2013 (UTC)

- I agree with Ozob. More, it is rather common that rather elementary notions need deeper mathematics that are not easy to explain elementarily. I have encountered this problem with Critical point (mathematics): before my edits, the lead were confusing between the critical points of a function and the critical points of the graph. To resolve this confusion, I had to understand that the critical points of the graph are, in fact, the critical points of the projection (of the curve) parallel to one of the axes. With this remark both definitions agree, but the latter needs the notion of differentiable map between manifolds. Nevertheless, the notion of critical point of a projection must appear in the lead, because it is fundamental for elementary sketching of algebraic curves and also for explaining the notion of stationary point in the orbit of a planet. I have tried to resolve this, but the article deserves further editing. D.Lazard (talk) 14:43, 18 October 2013 (UTC)

- I'm not convinced that grading articles' difficulty makes a lot of sense. For example, chain rule starts out very gently, but by the end it mentions Banach spaces, semimartingales, and other advanced topics. Or, as another example, the basics of Fibonacci numbers can be explained even to young children, but understanding the divisibility of Fibonacci numbers by primes requires some knowledge of quadratic residues in prime fields. Deep (even not-so-deep) subjects can be explained and understood on many levels, so we should expect our articles to have parts of inconsistent difficulty. Ozob (talk) 13:35, 18 October 2013 (UTC)

- Yes, the "ratings" would be a guide for editors what prerequisites that can be expected. The reader typically just stops reading without posting anything on the talk page if the article is not accessible. Isheden (talk) 10:00, 18 October 2013 (UTC)

## Polynomial

For anyone who hasn't seen the discussion and is interested, recent edits to the Polynomial article are beiong discussed at Talk:Polynomial#Recent edits. Gandalf61 (talk) 12:00, 24 October 2013 (UTC)

## Notation for the chain rule

An anonymous editor at Chain rule is claiming that "there are massive inconsistencies (and outright errors) in notation" in the article. He seems to be proposing wide changes; we have already reverted each other over the statement of the chain rule in the lede several times (though I think it might be best at this point to simply change the statement). See Talk:Chain rule#Notational consistency/rigor. Ozob (talk) 14:15, 25 October 2013 (UTC)

## "Shape analysis"

So the Topological_skeleton begins with a link to shape analysis, which sounds like it would be connected with a geometric-topological study of shapes, but rather the link is a redirect to Shape analysis (program analysis) which does not seem to be what was desired. I'm not familiar with any branch of mathematics called shape analysis, but if someone knows what it is and can create a stub I'd like to redirect. Otherwise, I would try to reword the lead of Topological Skeleton a bit. Rschwieb (talk) 15:19, 25 October 2013 (UTC)

- I redirected the shape analysis link to Shape analysis (digital geometry). These sorts of morphological and related analyses are used in computer vision and digital image processing, where the notion of "shape" extends to both topological and geometric properties of a set of pixels. --Mark viking (talk) 22:10, 25 October 2013 (UTC)

## Wikipedia talk:Articles for creation/Washer - test for time serie outlier detection

Hello mathematicians! Here's one more submission at AfC that may be of interest. —Anne Delong (talk) 21:06, 25 October 2013 (UTC)

- The article doesn't refer to any secondary sources, and there is no proof of notability. The first reference seems to be the primary source for this statistical test. The article is written to imply that the second reference makes use of this test, which would at least suggest notability, but the second reference predates the first one by a decade, so this seems unlikely to me. The other references are either to code samples or are not about the topic of the article. Ozob (talk) 15:33, 27 October 2013 (UTC)
- I just left a similar comment on the submission where it is more likely to be seen by one of the AfC reviewers. —David Eppstein (talk) 17:42, 27 October 2013 (UTC)
- Thanks, guys, I have declined it. One down, 1,409 more to go... —Anne Delong (talk) 20:23, 28 October 2013 (UTC)

- I just left a similar comment on the submission where it is more likely to be seen by one of the AfC reviewers. —David Eppstein (talk) 17:42, 27 October 2013 (UTC)

## Gyrovector space

Those with an interest in groups, Lorentz transforms and mathematical generalizations might like to add a comment at Talk:Gyrovector space#Proposed deletion. I'm mentioning here because this is unlikely to be watchlisted by many. — *Quondum* 07:55, 26 October 2013 (UTC)

## Anyone interested in mathematical physics?

Hello,

For the past few weeks, I've been working to bring the article AdS/CFT correspondence to FA status. It's obviously not a math article, but I have a feeling that there may be editors here who could help me out. If you're interested, please take a look at the article, and let me know what you think. You may support, oppose, or leave a comment at this page. Thanks. Polytope24 (talk) 19:37, 26 October 2013 (UTC)

## Superpartient number and Superparticular number

I have found these articles from "See also" section of Irreducible fraction. A *superpartient number* is simply an irreducible fraction greater than one. A *superparticular number* is a fraction of the form I do not know if this pedantic terminology is notable. Superpartient number is poorly sourced and almost an orphan (linked only from "See also" sections and user pages). The other article is better sourced and is linked (ouside of "See also" sections) from several articles about music theory, but it is not clear from these articles if the terminology is notable. Should they be prodded or proposed for AfD? D.Lazard (talk) 18:42, 27 October 2013 (UTC)

- A quick Google search [1], [2], [3], shows that "Superpartient number" seems to a be a medieval term for describing musical intervals, possible originating with Pythagoras [4]. "Superparticular number" seems to have a similar origin [5], [6], although it also seems mentioned in Boethian Number Theory, which I know nothing about. So these terms, if not notable could probably merged into, or at least defined in, a musical article section like Interval (music)#Alternative interval naming conventions where the superparticular number is already mentioned. --Mark viking (talk) 19:04, 27 October 2013 (UTC)
- Both titles get a reasonable number of hits in Google scholar, especially under slightly different names (superparticular ratio gets 75 hits, superpartient ratio gets 24; perhaps the articles should be moved to those titles?). So I think they're both notable. It should be irrelevant for notability that many of those hits are in historical studies rather than in pure mathematics. There are in fact a few articles in pure mathematics that use the "superparticular" terminology (I have written one myself, but it's not the only one) but it's possible that "superpartient" is used only historically and in music theory rather than in modern mathematics; if so, the superpartient article should be rewritten to focus better attention on what it's actually notable for. —David Eppstein (talk) 19:21, 27 October 2013 (UTC)

## Sbornik: Mathematics

It hasn't yet shown up on our current activity page, but Sbornik: Mathematics has been proposed for deletion. I suspect "the oldest mathematical journal in Russia" should be enough to meet the WP:NJournals criterion "The journal has an historic purpose or a significant history" but our article needs some help. For one thing, it is written in a way that makes it appear to be about the translation into English, rather than the original Russian journal itself. And for another it has no reliable sources. If someone here is interested in and/or knowledgeable of Russian mathematical literature, this might be a good one to work on. —David Eppstein (talk) 00:01, 28 October 2013 (UTC)

- I changed the name to the Russian version of the journal and added a link so the corresponding Википедия article. I also removed the prod, if someone wants to afd it they still can. If you just speak a little Russian it might be possible to make enough sense of the Google translation of the Russian Wikipedia article to merge with this article. I tried this last year with a French article last winter and got some reasonable results.--RDBury (talk) 05:07, 28 October 2013 (UTC)

## philosophers galore

https://en.wikipedia.org/wiki/User:Liz is promoting vast numbers of mathematicians and historians to the "philosopher" list. Is this activity beneficial? Tkuvho (talk) 17:33, 28 October 2013 (UTC)

- To give the latest example: the page for Emil Leon Post describes him as a mathematician and logician. What basis is there for claiming that he is a philosopher? Tkuvho (talk) 17:35, 28 October 2013 (UTC)

- What do you mean by "promoting"? RockMagnetist (talk) 18:12, 28 October 2013 (UTC)

- I thought if an academic was categorized as a "logician", this meant that their work involved the philosophical field of logic. Now that I see this questioned, I will cease while I see what WikiProject Mathematics folks say. I don't recall assigning any historians to the philosopher category as I have just been working on Logicians this morning. But I think "vast" is an overstatement. But I'll stop and check back to see what those who are more knowledgeable than I about this field come down on the categorization.
iz**L**^{Read! Talk!}18:15, 28 October 2013 (UTC) - P.S. I came to this WikiProject to learn what I could about mathematical side of logic and just happened to see this comment. Next time, if you have any questions, just leave me a message on my Talk Page. L.

- I thought if an academic was categorized as a "logician", this meant that their work involved the philosophical field of logic. Now that I see this questioned, I will cease while I see what WikiProject Mathematics folks say. I don't recall assigning any historians to the philosopher category as I have just been working on Logicians this morning. But I think "vast" is an overstatement. But I'll stop and check back to see what those who are more knowledgeable than I about this field come down on the categorization.

- According to the policy, a category must be a
*defining*characteristic of the subject (i.e., significant enough to appear in the lead) and should be verifiable. RockMagnetist (talk) 18:17, 28 October 2013 (UTC)

- According to the policy, a category must be a

- Also, the most specific category that applies should be used, and there is already the category of logician, so even if they are philosophers it would be redundant to add that category. RockMagnetist (talk) 18:25, 28 October 2013 (UTC)

- I agree, by the way, that Tkuvho should have contacted you directly first. RockMagnetist (talk) 18:27, 28 October 2013 (UTC)

- Just a couple of stray comments here:
- Part of the problem is that there is a branch of mathematics that, for historical reasons, is called mathematical logic, and among mathematicians, for short, it's often just called "logic". However, at least today, it's much more mathematics than it is logic.
- That said, don't go too far the other direction — a number of important mathematical logicians also count as philosophers. I would definitely keep Hilbert, Russell, Gödel, (Donald A.) Martin, probably several others. --Trovatore (talk) 18:33, 28 October 2013 (UTC)

- Mathematical logic and Philosophical logic have been areas of contention at WP for some time. Some editors see it as just one field of logic and others see these as distinct fields. There are certainly plenty of mathematicians who are more interested in logic as a mathematical system rather than as a foundation for philosophy. I recommend keeping them generally separate subfields and separate categories, but as Trovatore implies, articles/biographies are best considered on a case by case basis. --Mark viking (talk) 18:49, 28 October 2013 (UTC)
- That's a generally good summary in broad strokes but it understates the problem. Mathematical logic is not really "logic as studied by mathematicians as a mathematical system"; it's more accurate to say that it's just not "logic", in the general sense of the word, at all. It's a collection of mathematical disciplines that are
*called*"logic" for historical reasons. --Trovatore (talk) 20:45, 28 October 2013 (UTC)- I do not agree. The object of modern mathematical logic is essentially, about the following questions: "What is a correct mathematical reasoning?", "What is a proof?", "What is provable?", ... The fact that the answers need deep mathematics and the construction of elaborate mathematical systems does not mean that the questions that are addressed are very different of those of classical logic. D.Lazard (talk) 21:39, 28 October 2013 (UTC)
- Mathematical logic is generally thought of as the union of four fields, set theory, recursion theory, model theory, and proof theory. (To my mind one might easily add category theory and universal algebra, but for some reason this is not usually done.)
- The way it appears to me, your summary above applies primarily to proof theory, and hardly at all to the other three fields usually considered branches of "mathematical logic".
- My academic discipline, descriptive set theory, is definitely part of "mathematical logic", but it's hardly "logic" at all — it's more like the most abstract branch of real analysis. Now, that's not to say that logic-type questions don't come up; they definitely do come up (definable sets are classified by the complexity of the logical form of their definitions, and then the properties of such sets are studied). But the
*field*is not logic in the general sense of the word. -Trovatore (talk) 22:01, 28 October 2013 (UTC)- (I'm surprised Template:Ping hasn't commented here.) I don't fully agree with Template:Ping as to what (unadorned) "logic" is, but I strongly agree that "mathematical logic" and "philosophical logic" are distinct fields which rarely overlap, and a practitioner of one is rarely a practitioner of the other. (My fields of expertise include generalized recursion theory, set theory, and (generalized) universal algebra, so I fall strongly into the first category.) — Arthur Rubin (talk) 22:31, 28 October 2013 (UTC)

- I do not agree. The object of modern mathematical logic is essentially, about the following questions: "What is a correct mathematical reasoning?", "What is a proof?", "What is provable?", ... The fact that the answers need deep mathematics and the construction of elaborate mathematical systems does not mean that the questions that are addressed are very different of those of classical logic. D.Lazard (talk) 21:39, 28 October 2013 (UTC)

- That's a generally good summary in broad strokes but it understates the problem. Mathematical logic is not really "logic as studied by mathematicians as a mathematical system"; it's more accurate to say that it's just not "logic", in the general sense of the word, at all. It's a collection of mathematical disciplines that are

So, should Alexander S. Kechris be excluded from Category:Greek philosophers? Boris Tsirelson (talk) 07:25, 29 October 2013 (UTC)

- I wouldn't put him there. I don't recall that he's ever published a philosophical work. He's not
*uninterested*in the philosophical aspects (the first math logic course I ever took was from him, and I debated philosophical points with him — of course he had much more knowledge to go on, and I have since come around to a view much more like his). But to the best of my knowledge he's never attempted to contribute to philosophy in any formal way (e.g. publication). --Trovatore (talk) 18:11, 29 October 2013 (UTC)

- I wouldn't put him there. I don't recall that he's ever published a philosophical work. He's not

- Good question. However, contrary to the image I may present by that "answer", I am not a philosopher, so I would have to leave it to others to decide. I would lean against.... — Arthur Rubin (talk) 08:25, 29 October 2013 (UTC)
- To answer User Liz's question: Ivor Grattan-Guinness is a historian of mathematics. He was one of the academics added to the list of philosophers yesterday. Tkuvho (talk) 13:17, 29 October 2013 (UTC)

I have had to revert a few of Liz's recent edits, but on the whole, the overwhelming majority are just fine. What I think Liz doesn't realize is that being called a "philosopher" is apparently a huge insult to mathematicians, which is to completely misunderstand what a philosopher is. I have tried very hard to remove all the pseudophilosophy from the philosophy category tree and project (religion, esotericism, mysticism, and people handing out photocopied pages with no margins and tiny fonts on street corners, etcetera) and I have tried very hard to limit the category and project to scholarly and academic subject matter. However, even this is not good enough for some because there is deeply felt disrespect for even scholarly and rigorous philosophy as an academic field.

As far as categories are concerned, I believe we are at a fairly developed point to where we can categorize articles specifically without offending anyone. If a person is a set theorist, go ahead and put them in the set theorist category, and don't cry too much about the supracategory two levels up that puts logicians under philosophers. If we have specific catgeories, the problem solves itself. With that said, I am wondering what this group would prefer: Categegory:Recursion theorists or Category:Computability theorists? Greg Bard (talk) 22:24, 29 October 2013 (UTC)

- Since we appear to have actual recursion theorists on hand, I should let them speak for themselves, but the parent category for the field is currently called Category:Computability theory — it would make sense to be consistent with that, either by using Category:Computability theorists or by renaming the parent category. —David Eppstein (talk) 22:31, 29 October 2013 (UTC)

Just returning to this discussion to see whether I needed to revert my categorization and am surprised to see it already archived. This is one of the more lively WikiProjects I've come across. I intended to do all of the reverts necessary but it sounds like the consensus was that each person needed to be evaluated on a case-by-case basis and Greg Bard has already done this. Thank you, I didn't mean to create any extra work for anyone.

Needless to say, I will leave Category:Logicians alone from now on, I had no idea that this was a contentious area and I'm kind of shocked that a mathematician would be insulted to be thought of as working in an area of philosophy. Having worked through almost the entire category, I'd say that the mathematician/philosopher split in Logicians category is around 60/40 or 50/50.

To be honest, I think the average person (say, me) will see "logic" and think of the philosophy of logic, not mathematical logic. So, if there is such disdain for philosophy, in the future, categorize mathematicians as Category:Mathematical logicians, **not** Category:Logicians. Again, thanks for clearing this up! * L*iz

^{Read! Talk!}21:59, 17 November 2013 (UTC)

## Wikipedia talk:Articles for creation/Segal-Bargmann space

Dear mathematicians: I'm not sure if this is the right place to post this or if the physics experts should be notified instead. —Anne Delong (talk) 17:05, 29 October 2013 (UTC)

- This is a topic in mathematical physics, so at the risk of duplication, it is appropriate here and over at physics. --Mark viking (talk) 17:31, 29 October 2013 (UTC)

## New stub Gerrit Bol

In case anyone is interested we have an article google-translated from the Dutch and German wikipedia articles. **M∧ Ŝ**

*c*

^{2}

*ħ*ε

*И*23:15, 29 October 2013 (UTC)

_{τlk}- You can use Template:Translated page on the talk page of the article to indicate an article that was translated from another Wiki. I don't know if the use of this (or similar) template is mandatory, but it doesn't hurt to add it. Sławomir Biały (talk) 13:23, 30 October 2013 (UTC)