Wikipedia talk:WikiProject Mathematics/Archive/2011/Apr

Montante's method
Is this a notable article? Jakob.scholbach (talk) 21:19, 27 March 2011 (UTC)


 * It's entirely unreferenced, and there are no google scholar hits. I am suspicious of the supposed origin of this algorithm as well: the attribution feels like self-promotion and original research.  At any rate, there is a well-known fraction-free algorithm called the Bareiss algorithm from 1968 that predates the date of 1973 given here.  As far as I can tell, the two algorithms are the same or very nearly the same.  Sławomir Biały  (talk) 21:34, 27 March 2011 (UTC)


 * Eswiki has an article about the supposed discoverer. Doesn't look quite like run-of-the-mill self-promotion (modulo my lack of knowledge of Spanish). Could possibly be a case of people naming the result after the one among several independent discoverers that they identify with the most. If it's really the same thing, it ought to redirect to a common article, which then should document the various names. –Henning Makholm (talk) 22:08, 27 March 2011 (UTC)


 * But there is no evidence of anyone calling it Montante's method, and I can't find any reference to Montante regarding the method. The interview here refers to apparently unpublished papers by Montante Pardo, in which he apparently calls it the "Método Montante".  That's more than a little questionable, and does look very much like self-promotion and original research to me.  Sławomir Biały  (talk) 22:21, 27 March 2011 (UTC)


 * There are some Google hits in Spanish that look like the algorithm is taught under that name at various institutions in (mostly) Mexico:   . These links appear to be too different to all be self-promotion.
 * It feels at least plausible that some Spanish-speaking project member would be able to dig up a reliable source for the name. Anyone have access to a collection of Mexican linear algebra textbooks? –Henning Makholm (talk) 22:52, 27 March 2011 (UTC)
 * Perhaps Google scholar and Google books don't index Spanish-language books, but there is an utter absence of any kind of relevant hits for "Metodo Montante" or "Montante's method", and variants in reliable published sources. This very algorithm appeared in a widely cited article by Bareiss five years before Montante allegedly came up with it.  It seems to be a neologism that should be avoided.   Sławomir Biały  (talk) 23:09, 27 March 2011 (UTC)
 * So, should it be merged into the article on the Bareiss algorithm and attributed to him? JRSpriggs (talk) 09:30, 28 March 2011 (UTC)


 * Since the article seems to be of rather low quality, I nominated it for deletion. Jakob.scholbach (talk) 19:46, 31 March 2011 (UTC)
 * People here seem to call it Montante's Method. I found an interview published by a different university in the same city, here. I cannot truly attest to whether this method was found independently or not, but it is a method whose credit is given to him, at least here in the city. Perhaps another Mexican could confirm if the term is used outside of Monterrey/Nuevo León? And about the article deletion, please understand that EsWiki is waaaay behind EnWiki. If we were to quality-test every article, most would most likely disappear. While I agree that articles in Spanish should also follow Wikipedia's guidelines, I must also say that EsWiki is still a work in progress, and deletion of articles will damage more than what it would help, unless information found on them is proven to be actually false. Also, don't always expect Google Scholar hits about Mexican universities, you fail to see the (possibly sad) context they work in. — Preceding unsigned comment added by 187.138.107.2 (talk • contribs) 02:00:48, 14 October 2013 Note:Comment added after archival. ···V ani s che nu (mc/talk) 00:51, 30 October 2013 (UTC)

Fourth Dimension
An editor is insisting in marking the lead of Fourth dimension as dubious in "In mathematics, the fourth dimension, or a four-dimensional ("4D") space,[dubious – discuss] is an abstract concept derived by generalizing the rules of three-dimensional space". They say a four dimensional space could be any sort of space not necessarily Euclidean whereas others have said it referes in this instance to an extension of Euclidean 3-space. I would like to remove the dubious tag or otherwise resolve this. This is a bit similar I guess to the N-dimensional space business mentioned in a section above but as far as I can see there has been no real follow up to that, also I think they are a bit different in that N-dimensional space is actually used for many other things like configuration spaces whereas four-dimensional space is rather specific. Talk is at Talk:Fourth dimension. Dmcq (talk) 11:00, 31 March 2011 (UTC)


 * A mathematician could use the term 4-dimensional space in any discussion of a "space" that has "dimension" 4. For example, a vector space (over any field) with a basis consisting of 4 elements, a manifold whose charts map to R4, a manifold whose charts map to C4, a topological space of Hausdorff dimension 4, etc. So I feel strongly that 4-dimesional space should not be restricted to 4-dimensional Euclidean space. Mgnbar (talk) 12:57, 31 March 2011 (UTC)


 * The definite article seems out of place in that article's lede. CRGreathouse (t | c) 13:12, 31 March 2011 (UTC)


 * My understanding is that it's a historical usage, and the name of the article was taken from the book The Fourth Dimension by Charles Hinton (1912). &mdash; Carl (CBM · talk) 13:14, 31 March 2011 (UTC)


 * @Mngbar: If you ask a mathematician about "a point in 4-dimensional space", with no qualifiers and not saying "a four dimensional space", she will immediately assume you mean 4D Euclidean space. The term "4-dimensional space" as a proper noun is completely tied to Euclidean spaces in ordinary mathematical usage. We have to add other words to make it clear when we mean some other sort of four-dimensional space. &mdash; Carl (CBM · talk) 13:14, 31 March 2011 (UTC)


 * You raise a good point. Out of context, it would be unlikely for the mathematician to be referring to a particular complex manifold or topological space. However, I argue that "a point in 4-dimensional space" would just as commonly refer to an element of a four-dimensional vector space. In teaching, we often draw pictures of vector spaces, even when we have not assumed any Euclidean structure on them. Furthermore, a major point of contention at Talk:Fourth dimension is whether "four-dimensional space" should default to Euclidean or Minkowski space. There is a strong physics influence here, and maybe there should be. Mgnbar (talk) 13:43, 31 March 2011 (UTC)


 * Looking at the lead again the 'a' in 'a four dimensional space' looks out of place to me but the 'the' in 'the fourth dimension' is correct in the context of referring to 4 dimensional Euclidean space. The lead does talk about that physics deals with four dimensional spacetime but doesn't say strongly enough that the article is just dealing with a mathematical space rather than spacetime. The fourth dimension is also referred to in things like 'The Time Machine' where they mean something like a four dimensional Euclidean space where we are confined to a layer like in Abbot's book Flatland rather than anything like the modern conception of spacetime. Dmcq (talk) 20:44, 31 March 2011 (UTC)


 * There may be a strong 'physics' influence here, but in a broad way. In my experience, physicist avoid the term fourth dimention in favor of space-time. Ocassionally the will use the term 3+1 dimensions. On the other hand, there seems to be a popular understanding that time is the 'fourth dimension' such as what Dmcq mentions above. Without proof, I would guess that the most common reason for a user to goto the fourth dimension article is because of this popular misunderstanding of space-time. Some fraction would be interested in 4 spatial dimensions as well looking for concepts related to a non-self-intersecting Klein bottle, etc. I can't speak at all about why mathematicians would use it.


 * I have ran into similar arguments in other articles where people insist that space-time is four-dimensional or 4D (instead of 3D+1 or better yet not mentioning dimensions at all). I think part of the problem is combining fourth dimension with 4 dimensional (4D) space. To me at least 'fourth dimension' is a colloquial expression that could mean the extra dimension of either space or time, while 4 dimensional space could mean any group of 4 parameters and 4D is definitely 4 spatial dimensions.TStein (talk) 00:04, 2 April 2011 (UTC)

Gauss–Codazzi equations vs. Gauss–Codazzi equations (relativity)
I have no idea what these two are about exactly, but these two articles seems to be about the same thing. Opinions on what should be done? Headbomb {talk / contribs / physics / books} 19:16, 31 March 2011 (UTC)
 * They're the same, but both articles suffer from irreconcilable notational incompatibility. Sławomir Biały  (talk) 21:35, 31 March 2011 (UTC)
 * Well I redirected Gauss–Codazzi equations (relativity) to Gauss–Codazzi equations. If someone wants to bother doing a merge, go right ahead. Headbomb {talk / contribs / physics / books} 19:21, 1 April 2011 (UTC)

Making sense of 0.000...01
Our page http://en.wikipedia.org/wiki/Talk:0.999.../FAQ lists a number of frequently asked questions about 0.999... One of the answers to these questions deals with the "number" 0.000...01 (with an implied infinity of zeros before the last digit). The answer asserts, correctly, that this number is meaningless as a real decimal. I added a brief parenthetical comment here to the effect that one can make sense of such a number in a proper extension of R, providing a link to a page where this is discussed. The parenthetical remark was apparently too much for the guardians of purity at 0.999... and was reverted, most recently here. I would appreciate some input. Tkuvho (talk) 20:24, 31 March 2011 (UTC)


 * I think that is likely to just confuse people more. I don't have anything against the hyperreals, but I think that when people are already confused about something that's part of the grade school curriculum (real decimal expansions), we should be particularly hesitant to point them at even more difficult things that are not even part of the usual undergraduate curriculum (hyperreal decimal expansions). So I think the point of the FAQ is to be very simplistic. The article itself does discuss infinitesimals, as I think it should. &mdash; Carl (CBM · talk) 20:30, 31 March 2011 (UTC)


 * Are infinite decimals part of the grade school curriculum?? You are lucky if you get them in high school in many cases.  The purpose of a FAQ page is not to address a particularly young segment of our readership, but to attempt to answer typical questions that might arise on the talk page.  A number of inexperienced editors have reacted with interest to the suggestion that infinitesimals have a role to play here.  Frankly, I don't see why the talk page is any less of a legitimate place to discuss infinitesimals than the 0.999... page itself.  Tkuvho (talk) 21:00, 31 March 2011 (UTC)


 * I have seen grade school curricula with the fact that 0.999... = 1 (specifically, the 10x - x = 9x proof). Ozob (talk) 21:28, 31 March 2011 (UTC)


 * You mean, "the 10x - x = 9 proof". --Boris Tsirelson (talk) 07:01, 1 April 2011 (UTC)


 * Yes, thank you. Ozob (talk) 11:29, 1 April 2011 (UTC)


 * The fact that only rational numbers have repeating decimal expansion, and the algorithm for finding the corresponding rational from such an expansion, are common topics. Here is an NCTM worksheet that puts that skill in middle school. . &mdash; Carl (CBM · talk) 21:47, 31 March 2011 (UTC)


 * Those are extremely useful formulas, indeed.  From the point of view of a wider continuum, they hold up to an infinitesimal error if the infinity of periods is interpreted in terms of an infinite hypernatural.  From the real view point, all such infinitesimal differences are erased by an application of limit or standard part.  None of this contradicts the fact that student intuitions about "0.000...1" have a fruitful mathematical implementation.  Tkuvho (talk) 04:56, 1 April 2011 (UTC)


 * I think the game Hackenbush is a good illustration that these ideas are not altogether theoretical, that there may be very good reasons for saying that one 'value' is larger than another even though sticking them on the real line leaves no room for difference . Dmcq (talk) 11:45, 1 April 2011 (UTC)


 * Excellent point. There are several ways of making sense of the "0.000...01" intuition, Hackenbush being one of them.  These are closely related to the surreals.  Meanwhile, the maximal surreals have recently been shown to be isomorphic to the maximal hyperreals.  So really it's the same basic idea.  But getting this past the purists at the FAQ page seems to require a titanic effort.  They are currently busy eliminating any vestiges of an alternative to the reigning dogma.  Tkuvho (talk) 12:18, 1 April 2011 (UTC)


 * The article itself already does cover infinitesimals, of course; I don't think anyone is removing that. It seems to me that an FAQ does not need to cover every alternative theory. The point of the FAQ is to give very simple answers to a few questions, not to replace the main article. &mdash; Carl (CBM · talk) 12:22, 1 April 2011 (UTC)


 * Here's an analogy. Suppose we had a FAQ in solar system about whether the sun orbits a stationary Earth or the Earth orbits a stationary Sun. The right answer to that would be "modern science accepts the theory that the planets of the solar system are in orbit around the Sun (heliocentrism)." We would not want to go into length about how a few modern scientists have been interested in geocentrism and about how it is possible, after some effort, to reformulate things in a geocentric coordinate system. The lack of infinitesimals on the real line is similar: the thing which students need to learn first is that there are no infinitesimals on the real line. Only after they are comfortable with that fact could they be in a position to study other systems in which there are infinitesimals, but which (like geocentrism) are considered only potentially-useful fictions by modern researchers. &mdash; Carl (CBM · talk) 12:31, 1 April 2011 (UTC)


 * Thanks for your comment. I am obviously not going to pursue the FAQ thread if you are against it.  Perhaps we can settle for a more meaningful mention of infinitesimals in the lede of 0.999....  The following comment is somewhat predictable, but I will make it anyway: I agree with your geocentric/heliocentric analogy, provided the roles are reversed.  Tkuvho (talk) 14:05, 1 April 2011 (UTC)


 * Yes, the article should definitely discuss infinitesimals in some depth, since infinitesimals are the heart of the issue from my perspective. Another analogy that I have in mind is quantum mechanics. Bell's theorem shows that quantum mechanics is incompatible with the naive idea that an event in one place must take some amount of time to influence events in another place. Surely many people would find that surprising at first, and there are always some people who look for a way to work around the theorem (so-called "loopholes"). But the overall consensus of physicists (as far as I have been told) is that the theorem is correct in rejecting local variable theories in quantum mechanics. For an outsider like me, the primary question to ask is "why do physicists feel that way", rather than "what arguments can I use to avoid accepting what the experts have accepted". Similarly, I think that an article on 0.999 should emphasize why mathematicians treat it as equal to 1, which not only tells readers that fact but helps demonstrate the methodology of mathematics. &mdash; Carl (CBM · talk) 14:54, 1 April 2011 (UTC)

The readability of articles
I have just been reading a mathematics article about the Halting Problem (Turing et al) and found it to be very difficult to read. A lot of text books on subjects particularly in the field of science and maths have been written in this style and it leaves the reader frustrated and confused. Surely an encyclopedic article should be accessible to the widest audience possible? I think some simplification of the language with perhaps more steps and examples would help to get across to the reader some of the concepts involved. Readers are generally not stupid people (else why would they be there) but the knowledge should be communicated better. Language, next to knowledge, is the most important asset an encyclopedia can have.

Sam- Helsinki, Finland —Preceding unsigned comment added by 84.231.106.209 (talk) 08:21, 1 April 2011 (UTC)


 * Please have a look at the FAQ panel at the top of this page. Charles Matthews (talk) 08:31, 1 April 2011 (UTC)


 * It is not always easy to present technical material but if you come across a treatment that's more accessible, we can try to improve the wiki article as well. Tkuvho (talk) 10:43, 1 April 2011 (UTC)


 * I just had a look at the article and while there are a few things that could be tidied up it seemed to me to be on the better side as far as readability of maths articles goes. It is quite difficult remembering what problems one had learning something so probably the best thing to do is to flag the specific bits that first give trouble and the bits you find hardest to follow. Dmcq (talk) 11:09, 1 April 2011 (UTC)

The style/tone could also use some work there, e.g. Minsky exhorts the reader to be suspicious—although a machine may be finite, and finite automata "have a number of theoretical limitations": It reads like one of those controversial, he-says-she-says, social science articles. Tijfo098 (talk) 21:26, 1 April 2011 (UTC)

Absurd numbers
In view of the date, please have a look at this article and confirm my suspicions. JohnCD (talk) 19:07, 1 April 2011 (UTC)


 * It's a blatant hoax. I've marked it for speedy deletion.  Sławomir Biały  (talk) 19:14, 1 April 2011 (UTC)
 * Thank you, zapped. I just wanted a second pair of eyes. JohnCD (talk) 19:27, 1 April 2011 (UTC)

One of the more elaborate hoaxes. Created on the appropriate calendar date for such. Michael Hardy (talk) 22:40, 1 April 2011 (UTC)
 * I'm glad someone's watching. Still, I expect an interesting daily update tomorrow. :-)   Sławomir Biały  (talk) 01:04, 2 April 2011 (UTC)

Subdirect product and Subdirectly irreducible algebra
Can anyone think of a reason not to merge these? Tijfo098 (talk) 22:36, 1 April 2011 (UTC)

Frobenius determinant theorem
Frobenius determinant theorem is a near-orphaned article. So if the internal-link-muse speaks to you, figure out which articles should link to it and add the links. Michael Hardy (talk) 22:37, 1 April 2011 (UTC)

Futurama theorem
Does the Futurama theorem merit its own article ? A merger proposal is being discussed at Talk:Futurama theorem. Gandalf61 (talk) 15:15, 2 April 2011 (UTC)

Tits group
The group of Jacques Tits is important in mathematics, and it might be a suitable article for this project to improve to Featured Status in time for next year's April Fool's Day. Kiefer.Wolfowitz (Discussion) 17:44, 2 April 2011 (UTC)
 * I think DYK would make more sense, but DYK's strange rules make this incredibly hard, even with the special April Fools exemptions for timing. Hans Adler 18:32, 2 April 2011 (UTC)
 * Eligibility for DYK would probably require some (other!) editors writing a fivefold expansion in a sandbox. Kiefer.Wolfowitz  (Discussion) 19:35, 2 April 2011 (UTC)

There were a bunch of really obvious copy-editing issues that I've just taken care of. Michael Hardy (talk) 19:26, 2 April 2011 (UTC)

Simon Davis (mathematician)
Opinions of Simon Davis (mathematician)? It's been prodded. It says he applies the theory of perfect numbers to physics. I wouldn't have guessed those would be connected, but maybe I'm just naive. Michael Hardy (talk) 17:14, 2 April 2011 (UTC)


 * I started the article a long time ago; I don't think that I would start it now. His attempt to prove properties about OPNs via high-energy physics was a non-starter. CRGreathouse (t | c) 16:08, 3 April 2011 (UTC)

Ivar Ekeland
It would seem that we currently have no article about Ivar Ekeland, although nine other articles link to it. Michael Hardy (talk) 02:53, 3 April 2011 (UTC)
 * Kiefer.Wolfowitz (Discussion) 15:05, 3 April 2011 (UTC)
 * Kiefer.Wolfowitz (Discussion) 15:05, 3 April 2011 (UTC)


 * The German, French, and Spanish Wikipedias each have an article about him. Michael Hardy (talk) 14:56, 3 April 2011 (UTC)
 * That's helpful. (After the stressful shuttle-gossiping about the Monty Hall problem arbitration, I just have been writing about ridiculous topics, lately.) But I can translate the French article in a week or so. Kiefer.Wolfowitz  (Discussion) 15:03, 3 April 2011 (UTC)

Tkuvho has now created the article and some others have contributed to it. Michael Hardy (talk) 19:35, 3 April 2011 (UTC)

Lead image of Pi
The article Pi is about the mathematical constant. There is a question about whether the lead image should be relevant to the topic of the article, or should be an image of the Greek letter. Please comment at Talk:Pi. Sławomir Biały (talk) 19:41, 3 April 2011 (UTC)
 * If you have time while you're there, comments are being sought about moving Pi to π. Cheers, Ben (talk) 00:53, 4 April 2011 (UTC).

&pi; (pi)
The usage of &Pi; is under discussion, see Talk:Pi. 65.93.12.101 (talk) 01:27, 4 April 2011 (UTC)

John Rainwater
Many of you will enjoy reading about John Rainwater, who led the functional-analysis seminar at the University of Washington over a 5-decade career. His research achievements and long-relationship with UW are remarkable especially given his graduate-student record, which included plagiarism and planting an explosive device for his professor. Sincerely, Kiefer.Wolfowitz  (Discussion) 09:51, 2 April 2011 (UTC)

Note two related articles on other functional analysts, Robert Phelps and Peter Orno. Kiefer.Wolfowitz (Discussion) 02:34, 5 April 2011 (UTC)

Requested move of Fourth dimension
There's a request to move Fourth dimension to Four-dimensional space at Talk:Fourth dimension Dmcq (talk) 00:52, 5 April 2011 (UTC)

Boolean algebra content forks?
We seem to have three articles on the same subject: Does anyone know why? Are there any objective reasons to have three articles on this relatively elementary topic? &mdash; Carl (CBM · talk) 00:49, 29 March 2011 (UTC)
 * Boolean logic
 * Boolean algebra
 * Boolean algebra (logic)
 * FWIW, I had redirected Boolean logic to Boolean algebra because (1) it was clear after doing my research for the lead for Boolean algebra that it's the same topic, and (2) there wasn't much in boolean logic that isn't in boolean algebra; Venn diagrams are in, and even google queries. The only thing that is not in are SQL queries, but there aren't conceptually different (not when restrcited to discussion about boolean operators), and there are thousands of programming languages (PL) out there, why SQL in particular? There's a CS-ish article on boolean expression that could cover that, but as you can see from its stubby nature, nobody (except StuRat) thought the syntactic difference in how boolean expressions are written in various PLs matter much. Tijfo098 (talk) 02:15, 29 March 2011 (UTC)


 * Enough reasons for merging Boolean logic yet again (!) can be seen at the talk page section Talk:Boolean_logic and following section Talk:Boolean_logic. Hans Adler pointed out at the time that StuRat was in violation of WP:OWN and WP:POVFORK.  At the time StuRat had reverted the merging of his article by reviving it.  Just now he's reverted Tijfo098's merge of it.  In view of the many circumstances mitigating against this abysmally badly written article that StuRat owns, I've undone that revert.  If StuRat wishes to reinstate his article a third time, we can offer him the choice of whether he prefers to be blocked for WP:OWN, WP:POVFORK, or WP:3RR.  --Vaughan Pratt (talk) 03:26, 29 March 2011 (UTC)
 * Actually, StuRat promptly reverted my redirect, so I've started an official RfC on Talk:Boolean logic to attract opinion from previously uninvolved editors (and perhaps non-WPM editors as well to avoid some sort of systemic bias) as WP:DR recommends. Tijfo098 (talk) 05:55, 29 March 2011 (UTC)
 * Now, Boolean algebra (logic) needs more attention. There may be some material there worth merging (particularly the bibliography), but it seems too WP:NOTTEXTBOOK, e.g. explaining in detail how some expression is different if read as a Boolean rather than numeric. But even CS101 classes would give students a basic idea of type system. Tijfo098 (talk) 02:15, 29 March 2011 (UTC)
 * I do not own Boolean algebra (logic). It is true that I wrote more than 95% of it, but I have no objection to merging it with Boolean algebra.  I'm all for anything to reduce the mess that the absurd proliferation of articles on Boolean algebra has become. --Vaughan Pratt (talk) 03:26, 29 March 2011 (UTC)

Actually, that article is well-written, so perhaps there is a way to keep it available to the public on WikiMedia servers. I don't now much about that, but I think Wikiversity would accept that page as-is. Although Wikiversity doesn't get the same google juice as Wikipedia, we could link it from Boolean algebra; I'm not sure what are the standards for that. Perhaps someone here has experience in that area? Tijfo098 (talk) 12:21, 29 March 2011 (UTC)
 * I was going to suggest as an alternative to move it to Introduction to Boolean algebra, but there's already yet another (introductory?) article on the same topic there. Actually, except for the lead, that article is nearly indentical to what Boolean algebra has now, so it's conceivable to move Boolean algebra (logic) over it. (Some care is needed to probably attributed the current content of bolean algebra, so, perhaps the current Intro should be moved to a subpage of [[Boolean algebra first.) Tijfo098 (talk) 09:48, 30 March 2011 (UTC)
 * I would guess it is in the natural order of things to delete Boolean algebra (logic) which (at first view) is subsumed by the new Boolean algebra as far as coverage is concerned and which extra details can be either added to the current "Boolean algebra" page or moved to specialized pages. However, it would be a pity to just dispatch its contents and delete it. So maybe, as it was suggested above by Tijfo098, that might be a good article to Wikiversity (that I don't know well actually how it works but that might be an alternative if some people think it is relevant). --Hugo Herbelin (talk) 20:19, 30 March 2011 (UTC)
 * There are several options:
 * It could fill in wikiversity:Topic:Computer logic, although I guess it is just too big for that.
 * It could replace wikiversity:Boolean algebra (an abandoned page with nothing worth preserving).
 * It could make a new chapter of wikibooks:Formal Logic.
 * I guess the second option would be best because that's an isolated page where it wouldn't be immediately surrounded by inferior stuff. Another option would be to move it to Citizendium. It doesn't have a Boolean algebra article yet. Of course in none of these locations it would get much attention. Hans Adler 20:46, 30 March 2011 (UTC)
 * The second option is fine by me. The upshot as I understand it is that Boolean algebra (logic) would (for now) become merely a redirect to Boolean algebra (later it might be expanded to Main article status parallel to Boolean algebra (structure).  Its former text can go to wikiversity:Boolean algebra if that's kosher according to everyone involved.  It's fine by me---as I said, although I wrote almost all of it, I don't own it, Wikipedia does.  Or maybe it does: does Wikipedia continue to own text that has been deleted?  There should be a mechanism whereby Wikipedia abandons deleted text after a suitable grace period in order to allow others to claim or reclaim it.
 * While on the subject of lightening up, I propose to put a merge tag on Boolean algebras canonically defined aimed at merging its source-able parts into Boolean algebra (structure) which is in dire need of more substantive material.
 * In the opposite direction, I'm considering writing a new article Boolean algebra (presentations) as a Main Article covering the many presentations of both Boolean operations (featuring in particular Post's completeness characterization as it appears in Boolean algebras canonically defined, along with complexity results about relative succinctness of different bases) and Boolean axiomatizations (featuring complemented distributive lattices and Boolean rings and why both are important, but also listing some of the more impressively succinct axiomatizations such as Huntington's axiom, Robbins's axiom, Wolfram's axiom, etc.). Boolean algebra is unusual among equational theories in having a great many presentations.  Suggestions, objections, etc.?    --Vaughan Pratt (talk) 00:57, 31 March 2011 (UTC)
 * Looking again at Boolean algebra (logic) I notice a section on derivation that could form the nucleus of another Main-article subtopic of Boolean algebra, namely Boolean algebra (proof systems) or something like that. --Vaughan Pratt (talk) 01:00, 31 March 2011 (UTC)
 * I think they should rather be called something like proof systems in Boolean algebra or presentations of Boolean algebras. If they're sourceable, that is, and not original synthesis. --Trovatore (talk) 01:09, 31 March 2011 (UTC)
 * I think that a List of equivalent definitions of Boolean algebras (or whatever the title) would be very useful and I would indeed recommend it to be not too much pure original research nor too much textbook-style (and possibly not at all of this kind). Such an article could typically also include non-equational, e.g. order-based presentations.
 * About a "proof system" article based on Boolean algebra (logic), I'm a bit skeptical. Part of this section should better go to a new page equational reasoning which (in my opinion inappropriately) links to universal algebra but which I think deserves both a larger and more operational approach, for instance by connecting it to rewriting.
 * I don't know what a more-senior-than-me wikipedian would say here, but my impression is that wikipedia also needs experts like you for consolidating the existing articles and for weaving more connections between articles. An easy road map in this direction would precisely be to merge the "canonically" article, without losing the technical content (creating e.g. an Examples of Boolean algebras subtopic) and ideally adding the new technical contents mentioned in previous discussions: atomicity, completeness, freeness, saturation. --Hugo Herbelin (talk) 23:11, 31 March 2011 (UTC)

FWIW, there is a book chapter in Padmanabhan & Rudeanu (full ref given in Boolean algebra (structure)), so I have created Axiomatization of Boolean algebras as a redirect, but it's conceivable that it could become a list-type sub-article at some point. I don't have interest in developing it myself though. Tijfo098 (talk) 21:45, 1 April 2011 (UTC)

I'm not sure I understand what the purported proof systems article could contain that's not already in propositional calculus. Can someone enlighten me on that? Tijfo098 (talk) 21:57, 1 April 2011 (UTC)

Two-element one
There's a proposal to merge that as well at BATF. Tijfo098 (talk) 20:09, 6 April 2011 (UTC)

Lightstone
A. H. Lightstone is on sale here: http://en.wikipedia.org/wiki/Wikipedia:Articles_for_deletion/A._H._Lightstone Tkuvho (talk) 15:20, 31 March 2011 (UTC)


 * Could someone not involved in the discussion close it? Tkuvho (talk) 11:21, 5 April 2011 (UTC)
 * I wouldn't worry too much about that; it's linked to the appropriate daily logs, and the admins who patrol those logs generally close AfDs pretty punctually. —David Eppstein (talk) 15:58, 5 April 2011 (UTC)

Merge of subrandom numbers and Low-discrepancy sequence
I've proposed a merger of these articles at Talk:Subrandom numbers. It's not a merger that I myself feel competent enough to carry out, though. Are there any volunteers here? Sławomir Biały (talk) 11:51, 7 April 2011 (UTC)

New article Exact_Prime_Counting_Method
Could a mathematician take a look at this new article by a new contributor - it seems a bit odd to me but I don't know much about this subject.--Physics is all gnomes (talk) 13:31, 7 April 2011 (UTC)
 * It seems to be a very idiosyncratic version of the sieve of Eratosthenes. Sławomir Biały  (talk) 13:46, 7 April 2011 (UTC)
 * The statement in the lead: "It works efficiently for infinitely large primes." with a reference citing a post on google groups seems a bit dodgy. In fact, a lot of the article is a direct copy of that post, or vice versa. Is this saying anything useful or should it just be deleted?--Physics is all gnomes (talk) 13:55, 7 April 2011 (UTC)


 * (edit conflict) Somebody copied Sieve of Eratosthenes and threw in a little original research. It should be deleted. It references by M. M. Musatov so I guess we have another addition for Category:Suspected Wikipedia sockpuppets of Martin.musatov. See Talk:Mersenne prime for a disproof of his recent false claim  of discovering the largest known primes. PrimeHunter (talk) 13:57, 7 April 2011 (UTC)

Now proposed for deletion at Articles for deletion/Exact Prime Counting Method. -- The Anome (talk) 14:26, 7 April 2011 (UTC)
 * Cool, thanks guys.--Physics is all gnomes (talk) 14:34, 7 April 2011 (UTC)

MHP FAR
nominated Monty Hall problem 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. Tijfo098 (talk) 22:58, 7 April 2011 (UTC)

Cut locus
A somewhat odd and certainly under-referenced article. I looked it up after this |MathOverflow thread, which is certainly enough to show the interest of this concept as basic geometry. (Of which I wasn't aware.) The corresponding Cut locus (Riemannian manifold) is better, but still looks neglected. Charles Matthews (talk) 15:54, 8 April 2011 (UTC)

Artin's c.........
Artin's conjecture on primitive roots and Artin's constant substantially overlap with each other. Each has a hatnote linking to the other. Should they get merged? Michael Hardy (talk) 03:19, 9 April 2011 (UTC)


 * It appears the latter article was created yesterday and seemed to be pretty much an exact copy of the former, so I'm just going to go ahead and make it a redirect again (also note that the hatnote at the former is *not* a link to the latter, rather it is a link to something entirely different also called "Artin's conjecture"). RobHar (talk) 04:03, 9 April 2011 (UTC)

Recommendation to delete an uneeded redirect for Template:Maths rating
I wanted to let you know I submitted a recommendation to delete an unused and probably uneeded redirect relating to template:Maths rating. You can see the request here. --Kumioko (talk) 19:53, 10 April 2011 (UTC)

Inappropriate language
Inappropriate language is being used at http://en.wikipedia.org/wiki/Talk:0.999.../Arguments Tkuvho (talk) 11:25, 11 April 2011 (UTC)
 * If I understand that correctly, he's calling himself a moron. If he wants to do that, he's imho free to do so.--Kmhkmh (talk) 13:06, 11 April 2011 (UTC)
 * I think Nongendered added the "moron" sub-head when he responded to Leonid 2. It has now been removed by Staecker. Gandalf61 (talk) 13:14, 11 April 2011 (UTC)

Taylor series GAN
Taylor series, a top importance article, has been nominated for good article status (see WP:GACR for good article criteria). The review is here. We need reviewers and probably also editors. Sławomir Biały (talk) 18:18, 11 April 2011 (UTC)

Fuzzy matrix theory
Hi all, I stumbled upon Fuzzy matrix theory, and it looked slightly odd and fringey. The sole source is this which looks rather like cargo-cult maths to me; so I've sent it to AfD. All expert inputs would be welcomed on the AfD page... alternatively, if it could be rescued somehow, that's cool too. bobrayner (talk) 21:48, 11 April 2011 (UTC)

Center of alternating groups
Until my revision the article Center (group theory) stated that
 * "The center of the alternating group An is trivial for n &ge; 5."

That may be true, but it sounds as if A4 had a nontrivial center, which is not true, as can be seen in the Cayley table on the right. So maybe it should read
 * "The center of the alternating group An is trivial for n &ge; 4."

If someone knows that's true he may add it to the article. Until now the sentence is. Lipedia (talk) 09:42, 13 April 2011 (UTC)


 * Another way to see it is that $$A_4$$ is the group of Euclidean rotations preserving the regular tetrahedron. Each non-identity element stabilizes a unique line through the origin, and these lines can be different from each other.   Sławomir Biały  (talk) 10:46, 13 April 2011 (UTC)

Wright Camera
Help. Trying to wikify but, it needs some math expertise. Thanks,  Chzz  ► 05:58, 14 April 2011 (UTC)
 * Some Wikipedia talk:WikiProject Astronomy expertise would seem like a likelier choice to me. —David Eppstein (talk) 06:02, 14 April 2011 (UTC)

Proofs at Taylor's theorem
The article Taylor's theorem has a largish proliferation of proofs. (It used to have three, and has recently had as many as five. Now it's down to four.  At least I've recently simplified two of those considerably.)  I can see the usefulness of having some simple proofs that illustrate the basic relevant techniques (like the Cauchy mean value theorem, and restricting to a line segment in the case of several variables). However, there is some discussion of including complete proofs of basically all the results in the article. To me this seems rather contrary to the well-established consensus here, but I'd appreciate some outside input. Thanks, Sławomir Biały  (talk) 22:47, 11 April 2011 (UTC)
 * I don't like the idea either. It's an encyclopaedia, after all, and not a mathematical text. References can be used for most proofs. — Fly by Night  (  talk  )  21:46, 13 April 2011 (UTC)
 * But we also have the "Wikipedia is not paper" argument, as long as a proof is not really impairing the structure of the article and introducing other problem, it isn't really much of problem and can be tolerated in doubt.--Kmhkmh (talk) 16:28, 15 April 2011 (UTC)

Circle (topology)
Circle (topology) currently redirects to circle group. Some knot-theory articles mentioning circles probably should link to circle (topology) but not to circle group. I've made circle (topology) into a "redirect with possibilities". So how about those possibilities? Should, or will, someone do something? Michael Hardy (talk) 03:11, 14 April 2011 (UTC)


 * I see the article circle group has a unique reference, by one Hua Luogeng. I don't have access to his book so I can't tell if he uses the term "circle group".  Even if he does, does anyone else?  Usually this is called the unitary group U(1).  We should check into this being a neologism, and if so redirect it to one of the other pages.  Tkuvho (talk) 04:37, 14 April 2011 (UTC)


 * I've definitely heard it called the circle group. RobHar (talk) 04:53, 14 April 2011 (UTC)


 * "Circle group" is common parlance - plenty of hits on MathOverflow, for example. Even more for "circle action". Charles Matthews (talk) 06:58, 14 April 2011 (UTC)
 * I see nothing wrong with circle group, but I doubt circle (topology) ought to target there, because the circle group is an algebraic rather than topological structure (or, if you see it as a topological group rather than just a group, at least it's as algebraic as topological). It might make sense to just delete circle (topology) unless there's some more canonical spot to retarget it.  (Say, if we have an n-torus article, it could redirect there, to a section on the 1-torus.) --Trovatore (talk) 07:39, 14 April 2011 (UTC)
 * But when a knot-theory article refers to an embedding of a circle, where should the word "circle" link to, if not "circle (topology)"? Michael Hardy (talk) 14:18, 14 April 2011 (UTC)


 * Maybe it should redirect to unknot or vice versa. Tkuvho (talk) 14:28, 14 April 2011 (UTC)
 * Redirecting to unknot doesn't make sense. Whether a topological circle is knotted or not depends on how it is embedded in 3-space.  The topological circle is the same topological space regardless of any embedding. Michael Hardy (talk) 17:52, 14 April 2011 (UTC)
 * N-sphere seems a good choice, it does cover the general topological idea and the specific instance of the 1-sphere.--Salix (talk): 14:30, 14 April 2011 (UTC)

I just found that circle action was a red link from quaternionic projective space, but nothing else linked there. So I redirected it to circle group. Michael Hardy (talk) 14:33, 14 April 2011 (UTC)


 * I don't think that's a good idea. A circle action is a much more common term than circle group.  If anything it should be redirected to torus action. Tkuvho (talk) 14:35, 14 April 2011 (UTC)
 * Torus action currently redirects to toric variety. Michael Hardy (talk) 16:53, 14 April 2011 (UTC)
 * Add a few words to circle group to define "circle action", then. Kill off at least one of these. Charles Matthews (talk) 18:42, 14 April 2011 (UTC)

For now I've redirected circle (topology) to n-sphere, while leaving the "redirect with possibilities" tag intact. Michael Hardy (talk) 02:03, 15 April 2011 (UTC)


 * Also loop and free loop are related pages.  Somewhere there should be a disambiguation of these.  Tkuvho (talk) 04:45, 15 April 2011 (UTC)

Sub-Project for Prime Numbers
What about creating something like WikiProject Prime numbers. I know there is already the sub project WikiProject Numbers, but I (and I think some other editors as well) are especially interested in prime numbers. The project could serve as a centralized point of discussion for editors interested in prime numbers, but not working on other number related articles. The scope of this project would include all of the articles about the classes of prime numbers listed in List of prime numbers. It could also include articles where the number class includes a subsequence of prime numbers that do not have an own article (like for example Leyland number). Toshio Yamaguchi (talk) 16:05, 14 April 2011 (UTC)
 * I'm very much interested in primes but I have no interest in articles like 97 (number). Is this proposed project for me or not? CRGreathouse (t | c) 16:45, 14 April 2011 (UTC)


 * Given that Wikipedia talk:WikiProject Numbers seems to be near-deserted, I think we should not create further subprojects. List of prime numbers contains <100 articles, many of which are stubby (and will remain so), so having a project for them seems unnecessary to me. Jakob.scholbach (talk) 16:48, 14 April 2011 (UTC)


 * The projects focus could be extended by including other articles related to prime numbers, such as Riemann hypothesis, Goldbach conjecture or Prime number theorem, just to mention a few. And is the fact that one WikiProject is (nearly) dead an argument against creation of a new WikiProject? Taking into account WP:OTHERSTUFFEXISTS I would say not. Toshio Yamaguchi (talk) 17:11, 14 April 2011 (UTC)


 * OK, but <1000 articles even link to prime number. Creating a project with such a small scope requires time and energy that might better be spent otherwise. For example, bring prime number to GA status?! Jakob.scholbach (talk) 19:35, 14 April 2011 (UTC)
 * (ec) There is an ideal size for WikiProjects, and it's pretty close to the current size of WikiProject Mathematics. It's the size where communication on the project talk page actually happens. I.e. everybody finds the time to read everything, and that's not because almost nothing ever happens. WP:WikiProject Logic is an example for a WikiProject that is almost dead because it is too small. Your proposed WikiProject would be so tiny as to be almost certainly completely useless. Project space is full of the se attempted microprojects. See WP:WikiProject Mathematical and Computational Biology for a recent example (where I commented in more detail on the problem). Hans Adler 19:37, 14 April 2011 (UTC)


 * I agree with the points given. It should really be possible to handle it through this WikiProject. Toshio Yamaguchi (talk) 19:44, 14 April 2011 (UTC)


 * I tend to think that WikiProject Mathematics is not just larger but *far* larger than optimal for a WikiProject. Its success at this size is atypical, I think.  (That's not to say that the proposed project would be large enough to work!) CRGreathouse (t | c) 19:55, 14 April 2011 (UTC)
 * WPM is large in terms of articles but not that big in terms of active members. A split might not hurt but I don't see what's broken that we need to fix. For example this page isn't overwhelmed with posts and we've done a good job with organizing articles so people can find articles to work on in areas they're interested in.--RDBury (talk) 04:55, 15 April 2011 (UTC)
 * Point of information: I believe the Wikipedia term for a 'sub-project' is a WP:Task force. That might be more appropriate than an entire new WikiProject. --Qwfp (talk) 07:09, 15 April 2011 (UTC)
 * I might have proposed that as well, but even a task force should start with the momentum of a bunch of editors who want to work on a task. I am not seeing this (yet?) in the present case. Hans Adler 07:31, 15 April 2011 (UTC)
 * I would like to participate in that task force, if created. Toshio Yamaguchi (talk) 15:58, 15 April 2011 (UTC)

edits by Gustave the Steel
At Talk:0.999... inexperienced editors sometimes leave comments that are not directly related to improving the page. For this reason, a separate "arguments" page was created where such discussions can continue. Comments not directly related to improving the page are supposed to be moved to the "arguments" page. Recently, a couple of editors started a new trend of summarily deleting comments that are not to their liking. Furthermore, one of them threatened to "report" any further reinstatement of the deleted material. This would not appear to be consistent with minimal standards of politeness we expect at wiki. Tkuvho (talk) 04:42, 15 April 2011 (UTC)


 * I would suggest this is the sort of thing that is better solved by personal discussion, rather than a mass announcement. &mdash; Carl (CBM · talk) 01:45, 16 April 2011 (UTC)

Euler on infinite series
Euler on infinite series has been prodded for deletion. 64.229.100.45 (talk) 04:58, 15 April 2011 (UTC)


 * The topic is probably worth an article, but the present content of the article fails to demonstrate that. Michael Hardy (talk) 15:54, 15 April 2011 (UTC)

Derivations in articles (again)
I'm actually coming back to this as a result of some discussion at Talk:The Prisoner of Benda (where the ridiculous suggestion that minor copyedits to a proof were "original research"). In the past, we've had many discussions on inclusion of proofs in articles, and now there is even the dedicated subpage WikiProject Mathematics/Proofs. A basic editing principle that I have always adhered to is that it's better just to say why a result is true than to give a detailed derivation of it. This often means communicating the main ideas of the proof, without going into details. (In some sense, to "talk about the proof" rather than give it.) I find that this produces more seamless prose suited to an encyclopedia article. I've always thought that somewhere this was codified in a guideline or essay. It's certainly a point that I bring up in most discussions about proofs in mathematics articles. But it doesn't seem to be in either WP:MSM or WP:WPM/Proofs. Is this idea, or something like it, something we agree on? Should it be added to WP:WPM/Proofs? Sławomir Biały (talk) 11:47, 13 April 2011 (UTC)


 * Addendum: There's this is WP:MTAA:  "For example, a detailed derivation of a result is unlikely to be read by either a general reader or an expert, but a short summary of the derivation may convey a sense to a general reader without reducing the usefulness to an expert reader."   Sławomir Biały  (talk) 12:08, 13 April 2011 (UTC)


 * In principle I agree with your suggestion. I'm undecided, though, whether this should be hard-coded into a guideline. Especially because surveying hard proofs in this way can be much more difficult than following them in a more detailed manner. Jakob.scholbach (talk) 15:42, 13 April 2011 (UTC)
 * The French WP has elegant proofs that can be expanded with a touch of a button.


 * (The French write so elegantly!) 17:20, 13 April 2011 (UTC)
 * I think this also depends on ther context and scope of the proof in question. Occasionally giving the actual proof might be more accessible/faster to comprehend for readers than writing about it. But the biggest area of conflict (with non math editors for the most part) will be OR complains, so we should codify somewhere explicity that shortening/summarizing a (sourced) proof is not OR.--Kmhkmh (talk) 21:26, 13 April 2011 (UTC)

The editor at Talk:The Prisoner of Benda has become increasingly aggressive in his stance that summarizing published proofs and making slight copyedits to them is original research. I would appreciate it if someone uninvolved could have a look. Sławomir Biały (talk) 13:13, 14 April 2011 (UTC)
 * This is a very liberal interpretation of the claim I'm making. The issue is that the proof in question isn't really a published proof at all, but a screenshot from a TV episode. Andrevan@ 14:30, 14 April 2011 (UTC)
 * You've been warring to remove a section against consensus based on a tendentious interpretation of policy. You should know better. Sławomir Biały  (talk) 14:42, 14 April 2011 (UTC)
 * I hate to pull rank, but I do know better. I've been an admin on Wikipedia for almost 7 years. My argument is legitimate in the context of core content policies concerning verifiability, reliability, and original research. You may disagree with my interpretation, but you must assume good faith. Andrevan@ 15:14, 14 April 2011 (UTC)
 * More browbeating. I'm glad that, in reality, admins don't have any special status when it comes to interpretation of policy. It's pretty clear you have no idea how to correctly apply core policies to technical content, I'm sorry to say. Sławomir Biały  (talk) 15:22, 14 April 2011 (UTC)
 * I think your use of the phrase "More browbeating" is strange, previously used by Gandalf61 and Protonk, two other participants in the original discussion. I don't understand what you are accusing me of. Andrevan@ 16:08, 14 April 2011 (UTC)
 * You refuse to participate in any constructive process or discussion. On the discussion page, you accuse everyone else of misunderstanding policy, rather than respond substantively to the points made there. (I "don't understand synth", I " don't understand how citation needed tags work", etc.). You maintain an editing environment that is hostile to anyone who disagrees with you, and exhibit ownership of the article. Should I go on? Sławomir Biały  (talk) 16:20, 14 April 2011 (UTC)
 * I believe what I'm doing is constructively participating in the discussion. You may disagree with me, but there's nothing wrong with the way I'm going about it. I stand by the statement that your position on the issue does not exhibit understanding of the core policies on synthesis and verifiability. I would also add that you don't understand WP:OWNERSHIP, which refers to being possessive about material that was added. In this case, I believe the material should be REMOVED! This isn't browbeating, this is simple policy argument. Andrevan@ 16:26, 14 April 2011 (UTC)
 * Reverting to earlier versions despite consensus, trying to trump that consensus with obviously tendentious interpretations of policy, certainly interpretations unsupported by long-established best practices. Please, someone get involved and put a stop to this idiocy.    Sławomir Biały  (talk) 16:34, 14 April 2011 (UTC)
 * I believe that was a personal attack. Andrevan@ 16:36, 14 April 2011 (UTC)
 * Umm... What was? Calling this episode "idiocy"?  I suppose you'd better block me. You are an admin, after all, as you're so fond of pointing out.  Sławomir Biały  (talk) 17:08, 14 April 2011 (UTC)
 * The use of "idiocy" is certainly a personal attack. Obviously I'm not going to block you, simply advise you to take a step back and consider your words more carefully. Andrevan@ 23:05, 14 April 2011 (UTC)
 * Andrevan has started an RfC at Talk:The Prisoner of Benda. Sławomir Biały  (talk) 15:07, 14 April 2011 (UTC)

I think this ridiculous episode makes it glaringly obvious that we need clarity on whether summarizing proofs, or rewriting proofs in our own words without substantively altering them, or changing notation, is considered to be original research. It is painfully clear to me that, in the case of discussion, no original research has been committed at any time, in any version of the article under discussion. It has already been (convincingly, to my mind, by Kmhkmh), suggested that Andrevan has been misrepresenting the spirit, if not the letter, of WP:OR by insisting on an overly rigid interpretation of it. Also, a lot of this is explained by the fact that Andrevan is of the opinion that WP:V means that a lay-person should be able to verify the content of an article, without requiring any special subject knowledge. This is an untenable position for any encyclopedia that covers a wide range of serious topics, in my opinion. But there it is. Perhaps we need to formalize some clarity about that as well. Sławomir Biały (talk) 00:14, 15 April 2011 (UTC)


 * Somewhat, off-topic: I agree that some editors have ridiculous views as to what constitutes original research, even for WP purposes. Someone complained at the FAC for logarithm that assembling list of examples, all of which can be individually sourced is WP:OR. Duh, ... We do have WP:SCICITE to "hit them back" with, but of course, it's only a guideline, so if someone is hell bent on rules lawyering... Tijfo098 (talk) 07:17, 17 April 2011 (UTC)

Birkhäuser
May be a little off-topic here, but I don't know where else to ask. Can someone figure out what's the deal with Birkhäuser Verlag vs. the Springer math & science book series, which is still published under that imprint? We might need to create a dab for Birkhäuser. Tijfo098 (talk) 06:51, 17 April 2011 (UTC)
 * Answered at Talk:Birkhäuser Verlag. --Lambiam 19:52, 17 April 2011 (UTC)

Obstructionism
Blackburne, of A. H. Lightstone fame, is now attempting to delete a brief quotation at Adequality on the grounds that it is a copyright violation. Help! Tkuvho (talk) 12:24, 17 April 2011 (UTC)

Gopala–Hemachandra number AfD
There is a deletion discussion for this article which is getting a lot of attention. This is related to Fibonacci number which is #7 on our list of most frequently viewed (really more like #1 if you take out physics and statistics articles).--RDBury (talk) 18:10, 17 April 2011 (UTC)

Ebbinghaus
Can someone improve Heinz-Dieter Ebbinghaus before it's nominated for deletion? Tijfo098 (talk) 09:12, 18 April 2011 (UTC)

Clause (logic)
Maybe someone here has an opinion whether clause in logic only means a disjunction. Tijfo098 (talk) 16:14, 18 April 2011 (UTC)

DYK? for Ivar Ekeland (21 April)
The DYK nomination for the new article on Ivar Ekeland, which Tkuvho started (and which I expanded) should get a lot of DYK hits.
 * ... that, by writing about chaos theory and fractals (like the Julia set, animated), mathematician Ivar Ekeland helped to inspire Jurassic Park by Michael Crichton and Steven Spielberg?


 * Comment: Ekeland wrote about the Feigenbaum bifurcation etc., but not the Julia set (whose animation would compel DYK attention).

5x expanded by Kiefer.Wolfowitz (talk). Self nom at 10:55, 12 April 2011 (UTC)
 * ... that, by writing about chaos theory and fractals (pictured), mathematician Ivar Ekeland helped to inspire Jurassic Park by Michael Crichton and Steven Spielberg?
 * Kiefer.Wolfowitz (Discussion) 19:45, 13 April 2011 (UTC)


 * The DYK? appearance shall be 21 April, alas, without a picture. (An Easter topic will have an illustration.) Kiefer.Wolfowitz  (Discussion) 22:17, 19 April 2011 (UTC)

Non-Newtonian calculus
There's a number of links to non-Newtonian calculus being stuck in to various articles by User Talk:Smithpith (contribs). He has warnings in the talk page but we should figure out exactly what link should be kept if any I think. Dmcq (talk) 20:02, 18 April 2011 (UTC)


 * I'm sure that this has been a topic of discussion a long while ago. I don't remember what the outcome was. Is there a way to search the project's archives? — Fly by Night  (  talk  )  22:00, 18 April 2011 (UTC)


 * The story is quite sad. A number of non-mathematically educated users protested the AfD for non-Newtonian calculus and multiplicative calculus, and they were kept.  The articles have been a stain on Wikipedia ever since.  As a rule I try to make sure that nothing links to them; giving them any prominence amounts to WP:UNDUE, and even if they were notable, Smithpith links other articles to them much too heavily.  (Smithpith has also in the past admitted to being Michael Grossman, the co-inventor of non-Newtonian calculus).  I've cleaned up again; but the long term solution is to delete these articles once and for all. Ozob (talk) 22:34, 18 April 2011 (UTC)


 * Having said that, it does seem to have almost 80 publications as supporting references. What is to be made of that? Has anyone checked the validity of the references? — Fly by Night  (  talk  )  01:02, 19 April 2011 (UTC)


 * At the time of the AfD, I checked all of the references that were then in the article. It appeared that Mr. Grossman had cataloged every mention ever made of his book.  Frequently these were advertisements he had placed, and most of the rest were in lists of recently published books.


 * In retrospect, I was quite wrong. Mr. Grossman had not nearly cataloged every reference ever made to his work.  He has industriously remedied that defect, and the article now has, as you say, almost eighty references.  The article even tells you what kind of references they are: His book is "mentioned" or "reviewed" over and over.  The prominence of "mentions" and "reviews" in that list and the relative scarcity of citations evinces the yawn with which the book has been received.  But there are so many references I fear they will win over the voters at an AfD discussion.  I think a successful AfD would have to be done carefully and with much support from this WikiProject. Ozob (talk) 01:54, 19 April 2011 (UTC)

From Michael Grossman: I thought those links were pertinent. If I was wrong, I'm sorry. I have no intention of violating Wikipedia's rules. Smithpith (talk) 22:58, 18 April 2011 (UTC)


 * Wikipedia is not XXXXX. Kevin Baastalk 01:10, 19 April 2011 (UTC)
 * I removed the personal attack by Baas, leaving XXXXX instead. Kiefer.Wolfowitz  (Discussion) 19:43, 19 April 2011 (UTC)
 * This comment seems very inappropriate. I have no idea what it's supposed to convey. Sławomir Biały  (talk) 14:41, 19 April 2011 (UTC)


 * To Kevin Baas: Your comment seems to imply that you think that someone here has been acting like a Nazi. If made explicit, that would be considered a personal attack on that person. Left cryptic as it is, it unfairly impugns everyone in this dispute who disagrees with you. JRSpriggs (talk) 19:26, 19 April 2011 (UTC)

Images for articles about integer sequences
I created an infobox for articles about integer sequences a while ago (see Template:Infobox integer sequence for the template and Special:WhatLinksHere/Template:Infobox integer sequence for articles, where it is currently being used). I would like to include an image in every case, where the infobox is in use. For this purpose, it would be nice to have some input on which ways of visualizing integer sequences could be used for creating images for use in the infobox. My preference is in favor of ideas that can be easily realized using simple image editing software. Also I am aware of the visualization methods used by OEIS. Finally, the image should be interesting, without being distracting, even if only two or three terms of the sequence are known. Any additional input is welcome. Thanks. Toshio Yamaguchi (talk) 23:07, 18 April 2011 (UTC)
 * While we can always use more and improved images, mathematical concepts are often too abstract for an image to have any meaningful value. For example one of the articles that uses the template is Mersenne prime and I have a hard time seeing how an illustration would help make the concept more understandable. There are exceptions such as Ulam spiral for primes and Fibonacci spiral for Fibonacci numbers, but I don't think finding an image for every article is realistic. Perhaps it would be better to concentrate on adding the template to more articles since at the moment it's only used in 7.--RDBury (talk) 14:46, 19 April 2011 (UTC)
 * Neil Sloane recently changed the legal status of OEIS. Are the images released under a compatible license with ours? That might present the easiest solution if so. If not, Sloane can probably be persuaded to release the media under the CCA license if we think that's worth pursuing.   Sławomir Biały  (talk) 14:51, 19 April 2011 (UTC)
 * From here (see bottom of the page) and here it seems they are licensed under a Creative Commons Attribution Non-Commercial 3.0 license. From what I know this is incompatible with a use on Wikipedia, since our terms allow commercial use. So if there were any chance to use them, we would have to do under our guidelines related to WP:FAIRUSE. Toshio Yamaguchi (talk) 15:15, 19 April 2011 (UTC)
 * On the other hand I am unsure if the images are eligible for copyright at all per the concept of Threshold of originality. Toshio Yamaguchi (talk) 15:48, 19 April 2011 (UTC)
 * Licensing aside, Dr. Sloane's image probably isn't appropriate here. It's meant to represent that encyclopedia, not the general concept of an integer sequence. CRGreathouse (t | c) 19:53, 20 April 2011 (UTC)
 * It seems to me that the proposal is to have a different image for visualization of each integer sequence.  Sławomir Biały  (talk) 20:05, 20 April 2011 (UTC)
 * Yes, exactly. A different image for each sequence. Toshio Yamaguchi (talk) 23:31, 20 April 2011 (UTC)

Error term
....currently redirects to errors and residuals in statistics. That obviously doesn't make sense. So:
 * Disambiguation page?
 * Different redirect?
 * Article?
 * whatever..........?

Michael Hardy (talk) 19:31, 19 April 2011 (UTC)


 * I searched Wikipedia for "error term" and found that the statistical usage is much more common than all other uses combined. So if you decide to make a disambiguation page, then it should be listed first. Another use was for the Big O notation. JRSpriggs (talk) 19:47, 19 April 2011 (UTC)


 * To me an error term is a term representing the difference between the exact value of something and the approximate value given as some function (as in Taylor's theorem, where the error term is also called the remainder term, or in asymptotic results such as average orders of arithmetic functions). Often the error term isn't known that well, but a bound is known, which is the relation to Big O notation. I was pretty sure that on a measurement the error was simply called the "error", not the "error term", what do you mean by the "statistical usage"? RobHar (talk) 22:22, 19 April 2011 (UTC)


 * By "statistical usage" I meant the use of "error term" to refer to the observational error discussed at errors and residuals in statistics where it is called just "error". None the less, it is called "error term" in many of our articles, presumably because it is a term added to the theoretical value to get the measured value. JRSpriggs (talk) 07:35, 21 April 2011 (UTC)
 * I've usually seen it in connection with analysis (like Taylor's theorem) or numerical analysis. Redirecting it to statistics seems a little bit odd to me, but I don't have a firm opinion. 69.111.194.167 (talk) 09:40, 21 April 2011 (UTC)

Proposal to move Non-Newtonian calculus to Modifications of the calculus
I propose to move the controversial page Non-Newtonian calculus to a more appropriate title Modifications of the calculus. It can be decided later what to do about multiplicative calculus. The term "non-Newtonian" is a neologism coined by the author of the book that has not been widely accepted. The term makes it appear as if this approach is a significant modification of the calculus, somehow going against the Newtonian approach. Meanwhile, the main idea of this approach seems to amount to apply log to a product before differentiating. Whatever the possible applications of this method may be in engineering, the title should reflect the contents more precisely. Also in any future AfD the participants will have a more accurate picture of the intrinsic merit of the approach. Tkuvho (talk) 10:09, 21 April 2011 (UTC)


 * WP:TITLE says that, in general, an article's title should be "what reliable English-language sources call the subject of the article". So if the widely accepted term for the subject of this article is not "non-Newtonian calculus", then what is it ? "Modifications of the calculus" sounds both clumsy and vague - unless there is a source for this alternative title, are you not in danger of replacing one neologism by another ? Gandalf61 (talk) 10:24, 21 April 2011 (UTC)


 * No, this is not a new neologism, because the new title is meant to be descriptive. You claim that the name "non-Newtonian" is "widely accepted", but one of the editors above claims that the theory has received a lukewarm response and almost ignored.  My main point is that the "non-Newtonian" business is very misleading, as it implies some major foundational innovation.  Such an innovation is just not there.  I looked up their 1972 book.  In the introduction they claim that their theory is "very different" from that of Newton and Leibniz.  How many people believe that?  Tkuvho (talk) 10:55, 21 April 2011 (UTC)


 * But the article is "about" the 1972 book more than anything else. I don't think we should have an article about this book, given the utter lack of meaningful critical response, but it already survived an AfD since folks were duped by the number of references. Also, there are (presumably) other modifications of the calculus (nonstandard calculus, for instance), and just moving this article would be giving grossly disproportionate coverage to one (rather nonnotable) such modification. I would advocate simply redirecting the article to multiplicative calculus. Neither article is good, but I'd rather have one bad article than two.  Sławomir Biały  (talk) 11:15, 21 April 2011 (UTC)


 * Other editors (in a subsection above) have similarly expressed the sentiment that the article is not notable, and also noted the difficulty of succeeding in an AfD. My point is that such difficulty is exacerbated by a misleading title, which might lead inexperienced editors to oppose deletion of what is presented as some kind of revolutionary alternative to Newton.  I think the title "multiplicative calculus" is similarly misleading, as it suggests that we have some kind of a new calculus here.  "Modification" seems to be the right description; whether or not such a modification is notable can be determined in a future AfD. Tkuvho (talk) 11:28, 21 April 2011 (UTC)


 * The place to take notability concerns is clearly AfD. The previous AfD on Non-Newtonian calculus was over 2 years ago, so a long enough interval has elapsed for a second AfD. Present your arguments in a clear way that even those pesky "inexperienced editors" can understand, and establish consensus through discussion. FWIW, my view is that changing an established article's title in place of or before an AfD seems awfully close to gaming the system. Gandalf61 (talk) 11:51, 21 April 2011 (UTC)


 * A potential AfD is a separate issue. The current grandiose title is a neologism that has not been widely accepted.  I am proposing a more modest title that's descriptive of the contents.  The current grandiose title games the system in favor of a potentially unnotable article.  Tkuvho (talk) 12:18, 21 April 2011 (UTC)


 * The title of the article says nothing about its notability. It merely, describes the subject in the term most commonly used to describe the subject by people that talk about the subject. Your argument seems to be that almost nobody discussed this subject, that could very well be, but that is an argument for deletion not renaming. If you want to rename the article, you will have to provide some evidence of sources discussing this subject, which do not call it non-Newtonian calculus.
 * (And just for the record your proposed new name for the article is grammatically flawed.) TR 12:38, 21 April 2011 (UTC)
 * Suggestion: move it to Non-Newtonian Calculus, and add . Then the introduction would be modified to make it refer just to the book of that name. That way, it is clear that it is the authors' choice of phrase. Otherwise you would have to have something cumbersome like Grossman and Katz modifications of calculus.  Xanthoxyl  &lt; 12:54, 21 April 2011 (UTC)
 * Good idea - Non-Newtonian Calculus, italicised in line with WP:MOSTITLE, is clear and unambiguous. Works for me. Gandalf61 (talk) 13:35, 21 April 2011 (UTC)
 * Since it's clear that this article is primarily about the book, it's high time that it go back to AfD. This is not a notable book, receiving only 19 citations on Google scholar (five of which are self-citations).   Sławomir Biały  (talk) 13:42, 21 April 2011 (UTC)
 * I agree that the italic version might be a move might be a good idea. One could also consider to the term in quotes or qualifiers in the article itself (for the first bold print). But moving it to Modifications of the calculus is not a good idea for the reasons stated Sławomir Biały & Gandalf61. The appropriate way to deal with a (unnotable) neologism is an AfD. If that fails we will have to live with neologism. However we still can indicate the neologism/lack of notability character in the article itself by using qualifiers and insisting on intext attribution wherever it maybe reasonable, but we should not change the name to something which isn't really used in the sources or by the few people actually refering to it.--Kmhkmh (talk) 13:52, 21 April 2011 (UTC)

The article has been nominated for deletion: Articles for deletion/Non-Newtonian calculus (2nd nomination). Please direct your comments there. Sławomir Biały (talk) 14:38, 21 April 2011 (UTC)
 * Are the proposed & rejected "Modifications" all standard in contrast to non-standard calculus following Abraham Robinson and exemplified by Jerome Keisler's introductory textbook? (I have reorganized the lead of that article but it will benefit from further rewrite. I have only slightly addressed the criticisms by myself and others. See multiple sections of Talk:Non-standard calculus.) --P64 (talk) 19:12, 21 April 2011 (UTC)
 * It has nothing to do with non-standard calculus, I believe yes is the answer to your question though of course one could always develop 'standard' calculus using non-standard calculus - that's what a lot of it is about! Dmcq (talk) 22:24, 21 April 2011 (UTC)

List of numeral systems
I've created List of numeral systems and would appreciate help making it somewhat complete. --Beao 17:36, 21 April 2011 (UTC)

Radio 4 mathematics collection
The BBC has a collection of audio programs related to mathematics at. Many of these are episodes of the radio series "In Our Time". Just mentioning it for general interest but I'm also thinking it would be a worthwhile project to make sure we have a link to each program in the "External links" section of the corresponding WP article.--RDBury (talk) 17:38, 20 April 2011 (UTC)
 * Update: I added links to five of the "In Our Time" episodes so all are done except "Renaissance Mathematics" for which we don't have an article, just a section in History of mathematics.--RDBury (talk) 03:36, 21 April 2011 (UTC)
 * Thanks for posting those links. I listened to most of them. I even forwarded the infinity one to a couple of non-mathematical friends. It's funny though. In all of the attempts to simplify maths for a general audience, I always find that the result loses all of its beauty. For me, the complexity and the structure of maths is what makes it so interesting. Sadly, some of those links perpetuated the myth of mathematicians solving equations all day. There were lines like "Mathematicians love numbers because&hellip;", and they interpreted Chaitin's constant as meaning that there are "infinitely many unsolvable equations." But, hey. what can we do? Once again, thanks for linking to those radio programs. — Fly by Night  (  talk  )  20:55, 22 April 2011 (UTC)

Radius one or diameter one in circle rolling
I'm looking for reactions to the idea at File talk:Pi-unrolled-720.gif. In a nutshell, the idea is to make a relatively minor change to that animation changing the radius from 1/2 to 1 and the circumference from π to 2π (I don't really know whether this would be controversial, but at least to me the reasons for it are pretty sound and in line with the mathematical tendency to deal with circles of radius one). The intro (where it lines up the circles) would probably best be changed to somehow visually emphasize the radius a bit more than the diameter. Whether the new image replaces the old one or just gets used places like Radian and Turn (geometry) is to be determined. If people like the idea, we can presumably get help from Graphic Lab/Illustration workshop and/or Graphic Lab/Photography workshop (I would have thought the former, but I guess the people at the latter are more accustomed to working with raster images). Kingdon (talk) 01:33, 23 April 2011 (UTC)

Provably/probably
I expect most of us who have math articles on our watchlists see this from time to time -- an article contains the word provably, used correctly, and someone, usually an IP, changes it to probably.

I was just idly wondering if anyone else has an opinion on this. Is it a specific person who just likes to do this for fun, maybe figuring it's a subtle change that might escape notice? Or, is it that a lot of people just don't know the word provably and fix the "typo" in good faith?

Either way, it seems likely that some such changes go uncaught. Just thought I'd mention it so that the next time one of us sees the word probably in a math article, we might give half a second's thought to whether it's really supposed to be provably. (Or, I suppose, the reverse is also possible, but I don't recall an example of that.) --Trovatore (talk) 04:56, 23 April 2011 (UTC)


 * I think the people who do it are honestly confused. I would expect that some spellcheckers don't know the word. And as Spanish speakers tend to conflate v and b it's actually plausible as an error. Hans Adler 16:05, 23 April 2011 (UTC)


 * Suggest that when "provably" is used, it is linked to a definition (something on the Proof page, probably (no pun intended)).


 * On our (ugly) sister site ProofWiki we have the same problem with getting "iff" changed to "if" so whenever I see this I change it to a specific link to a definition of "iff" as I can't abide "if and only if". --Matt Westwood 05:18, 23 April 2011 (UTC)
 * It's a bit of a tangent, but I (for one) can't abide "iff" in formal writing such as we should be using on Wikipedia. I'll happily use it on talk pages and other less-formal contexts. MOS:MATH agrees (see the section "Writing style in mathematics"). So unless you want to build consensus to get the MOS changed, please just spell it out. (Also, I am a victim of the provably/probably thing — one of my papers uses "provably" in the title and it has occasionally been cited as "probably".)—David Eppstein (talk) 05:31, 23 April 2011 (UTC)
 * I agree. By my standards iff is properly confined to blackboards or quick notes; its only function is to be able to be written quickly.  I also don't agree with linking it (or provably).  Links are primarily intended to enable in-depth reading on an important aspect of the topic being read.  I dislike links whose main purpose seems to be to say "hey, this is a word I'm not sure you know". --Trovatore (talk) 07:26, 23 April 2011 (UTC)
 * Just to set you all straight, I'm not talking about Wikipedia here, I'm not suggesting "iff" be used on this site, that would indeed be outrageous. I was talking about what we do on ProofWiki where the rules are different because we're doing a different job.
 * I replied to this post because I was able to offer a suggestion as to what to do in this circumstance. But okay, if the page uses a word which confuses people enough to want to change it "because it's obviously wrong", then you definitely need *some* sort of means to tell the reader: yes I *do* mean that word.
 * So, a further suggestion: how about a link to Wiktionary? --Matt Westwood 09:33, 23 April 2011 (UTC)
 * As for "provably", there are probably many cases where it can be dropped altogether. E.g. "The set of prime numbers is provably infinite." -> "The set of prime numbers is infinite." There are variations that might also cause confusion, "provable" vs. "probable", "provability" vs. "probability", and these might be more difficult to deal with. Perhaps in such cases a hidden comment can be added such as . If we start adding links every time there is a word someone might not understand the articles will fill up with distracting link symbols. Someday someone will add a browser feature where clicking any word will look it up for them on their favorite on-line dictionary; we shouldn't try to implement it here.--RDBury (talk) 15:52, 23 April 2011 (UTC)
 * I recommend . I think that's the "official" way to mark something as "meant". -- John of Reading (talk) 16:27, 23 April 2011 (UTC)
 * That looks good. Thanks! --Trovatore (talk) 17:03, 23 April 2011 (UTC)

Haynsworth inertia additivity formula
I've created a new article titled Haynsworth inertia additivity formula.

That article and Sylvester's law of inertia treat of this particular concept of "inertia". Is this so called because of a conceptual connection with physical inertia? If so, those article ought to explain the connetion.

To do:
 * Explain that connection.
 * Otherwise improve the article.
 * Link to the article from appropriate other articles.

Michael Hardy (talk) 18:07, 23 April 2011 (UTC)


 * The connection is the inertia tensor, for what it's worth.  Sławomir Biały  (talk) 20:44, 23 April 2011 (UTC)
 * Thank you. I wouldn't mind if some linear algebra textbooks at least mentioned that when they mention the word "inertia". Michael Hardy (talk) 00:33, 24 April 2011 (UTC)

List of matrix topics?
Should we have a list of matrix topics or list of matrix theory topics? Michael Hardy (talk) 18:15, 23 April 2011 (UTC)


 * Navboxes are more useful than lists particularly for slow connections. You can see a navbox without downloading another page.  Also, navboxes can be structured and thus carry more information than alphabetic lists.  Tkuvho (talk) 21:39, 23 April 2011 (UTC)

But navboxes seem to be for navigating, whereas lists are (partly? largely?) for browsing. Michael Hardy (talk) 00:29, 24 April 2011 (UTC)
 * Does Category:Linear algebra help? 69.111.194.167 (talk) 00:38, 24 April 2011 (UTC)
 * Not really. It's merely a category, not a list.  List of linear algebra topics is somewhat more to the point. Michael Hardy (talk) 04:21, 24 April 2011 (UTC)

Branching random walk
Branching random walk is a stubby new article. Work on it. Michael Hardy (talk) 21:03, 22 April 2011 (UTC)


 * Good luck! Shouldn't it be "branching random-walk", per MOS? Kiefer.Wolfowitz  (Discussion) 22:00, 22 April 2011 (UTC)
 * In most cases, modifiers right-associate by default, and you need hyphens only to mark exceptions from that. --Trovatore (talk) 22:02, 22 April 2011 (UTC)
 * My reading of the MOS, and my discussion of "real vector-space" with MF, suggests that the MOS mandates recommends the suggested hyphenation, which is consistent with Michael Dummett's book.
 * I already moved the page. However, "anybody attempting to use hyphens consistently shall go mad"! Kiefer.Wolfowitz  (Discussion) 22:25, 22 April 2011 (UTC)
 * OK, I totally disagree with that move. Kiefer, are you a native speaker?  To my ear/eye/whatever this hyphen is very jarring.  Who is MF, and where do you see this in the MOS? --Trovatore (talk) 23:36, 22 April 2011 (UTC)
 * Totally see my user page for information about me. For MF, search among the primary writers of featured articles on English WP. See the MOS, also.  Kiefer.Wolfowitz  (Discussion) 23:42, 22 April 2011 (UTC)
 * I don't see on your user page where it says whether you're a native speaker of English. Oh, never mind; it was under a "show". You claim to have a "professional" level of English.  This is not the same as having a native ear.  How about just answering the question about MF rather than telling me where to search?  Please point me to the clause in the MOS on which you're relying. --Trovatore (talk) 23:49, 22 April 2011 (UTC)
 * Sweden has a number of probabilists analyzing branching processes and random walks. Perhaps it is not obvious that branching modifies "random walk"? Kiefer.Wolfowitz  (Discussion) 23:46, 22 April 2011 (UTC)
 * What else is available for it to be modifying? --Trovatore (talk) 23:49, 22 April 2011 (UTC)
 * The MoS doesn't mandate using a hyphen in every compound attributive, and it gives some examples where adding a hyphen changes the meaning. I would say that in "branching random walk", a hyphen is not needed because it is clear that "branching" modifies "random walk", rather than "random".  By contrast, a hyphen would be necessary if we meant "branching-random walk" (whatever that could mean).  A simpler example: we wouldn't write "hot chicken-soup" (to mean chicken soup that is hot), but we would need to write "hot-chicken soup" (soup made out of hot chickens).   Sławomir Biały  (talk) 23:58, 22 April 2011 (UTC)


 * Sławomir, "branching" modifies the object "random walk". The problem for civilians is that "branching", like "halting", could modify "walk" directly.
 * Of course, we both think that almost all readers are familiar with chicken soup.
 * However, an undergraduate looking to write a B.S. thesis might read the branching random-walk article without familiarity with branching processes or random walks, and benefit from the hyphen. Please read the article in the state I found it, and tell me whether I was right to be concerned about the needs of civilians. Kiefer.Wolfowitz  (Discussion) 00:25, 23 April 2011 (UTC) (There was an EC that prevented my direct answer before, 01:40, 23 April 2011 (UTC))

For MF, search among the primary writers of featured articles on English WP. Malleus Fatuorum and I discussed hyphens previously, with good humor, also. See the MOS, also. Kiefer.Wolfowitz (Discussion) 23:42, 22 April 2011 (UTC)
 * Maybe George Bush has corrected others' pronunciation of "nuclear" the way you Trovatore offers advice on hyphens? The MOS states that hyphens are used to prevent ambiguity. Please see Dummett's book for clear and firm advice. Kiefer.Wolfowitz  (Discussion) 00:10, 23 April 2011 (UTC)


 * "Branching", like "halting", could modify "walk" directly.  Kiefer.Wolfowitz  (Discussion) 00:10, 23 April 2011 (UTC)
 * I suppose, in an utter vacuum. No one's going to hear it that way, though.  I think this hyphen is completely ill-advised.  I'm going to revert your bold move and you can raise an RM if you like. --Trovatore (talk) 00:13, 23 April 2011 (UTC)
 * Your last sentences don't make much sense, and argue further that you should not be dispensing prose advice, at least not at this hour. Look at the state of the article before I copy-edited it. Kiefer.Wolfowitz  (Discussion) 00:17, 23 April 2011 (UTC)
 * Please contribute to the article, before edit warring. Kiefer.Wolfowitz  (Discussion) 00:21, 23 April 2011 (UTC)
 * What edit warring? WP:BRD. --Trovatore (talk) 00:26, 23 April 2011 (UTC)
 * Look, Trovatore. You have been insulting. Do you know anything about stochastic processes? Hardy certainly does, but the article's state was far below his usual standard. I fixed the prose, and provided links to the related areas. You have contributed nothing to the article. Let Hardy revert the move if he wants, when he next edits. I certainly will respect his judgement.
 * Did you check Dummett's advice. Have you, apparently a logician, heard of him? Kiefer.Wolfowitz  (Discussion) 00:32, 23 April 2011 (UTC)
 * I have been insulting? That's pretty rich.  I leave it to fair-minded observers to look at the exchange and see who has been more insulting and first.  Maybe you got upset because I asked if you were a native speaker?  It was a fair question, I think.
 * Sure, I've heard of Dummett. I don't necessarily agree with him on foundational philosophy, but I got a lot out of Cantorian Set Theory and Limitation of Size.  I have never seen a style manual by him and would not take him as an authority on that. --Trovatore (talk) 00:52, 23 April 2011 (UTC)
 * I dislike Dummett's prose style, but I find his comments thoughtful. Dummett favors clarity and hence suggests hyphens to avoid ambiguity and to save the reader's time. Kiefer.Wolfowitz  (Discussion) 01:46, 23 April 2011 (UTC)
 * Sławek is absolutely dead on. Your hyphenation is utterly tin-eared.  Get consensus first. --Trovatore (talk) 00:31, 23 April 2011 (UTC)
 * Who are you to question my English or to take that tone with me? I rewrote the article, repaying a small part of the kindnesses that Michael Hardy has shown me on hundreds of occasions. Write some content, as way to atone for your sins.  Kiefer.Wolfowitz  (Discussion) 00:53, 23 April 2011 (UTC)
 * I stand by my characterization. --Trovatore (talk) 00:54, 23 April 2011 (UTC)
 * LOL  Kiefer.Wolfowitz  (Discussion) 01:24, 23 April 2011 (UTC)
 * Please fix the damage you did to my signatures. Thanks, Kiefer.Wolfowitz  (Discussion) 01:32, 23 April 2011 (UTC)
 * Done. Editing mistake; somehow I got the text in two places. --Trovatore (talk) 01:35, 23 April 2011 (UTC)
 * Thanks! Kiefer.Wolfowitz  (Discussion) 01:41, 23 April 2011 (UTC)
 * Please, no hyphen, it is awful. 69.111.194.167 (talk) 18:25, 23 April 2011 (UTC)
 * Without commenting on the other aspects of this discussion, I agree: the hyphen needs to go.  CRGreathouse (t | c) 20:17, 23 April 2011 (UTC)
 * To comment a little further, I think older works in British English use hyphens more than contemporary or American works do. I can get the impression that Malleus Fatuorum is influenced more by dated British usage than a lot of the rest of us are, which would explain his take on this.  To me (US English speaker) the hyphens come across as dated and maybe stilted.  I remember an elderly physics professor from a Commonwealth country who wrote "wave-guide" and pronounced it with equal stress on both words, which came across to me as marked.  Anyone I know would have written "waveguide" or "wave guide" and stressed "wave" when speaking.  Perhaps this should be left up to Michael Hardy per WP:RETAIN.  69.111.194.167 (talk) 00:53, 24 April 2011 (UTC)
 * You may have misunderstood Malleus: He wanted consistency, and we had a polite discussion of hyphens. Malleus is an excellent writer---unlike the fellow who totally stood behind his synaesthetic complaint that my hyphenation was tin-eared ....
 * Ditto with David, who thought my hyphenation to be old-fashioned, at least with "real vector-space". :-)
 * I'm glad somebody agrees that we should let Michael decide, respecting his contributions. Kiefer.Wolfowitz  (Discussion) 20:51, 24 April 2011 (UTC)
 * I'm a fan of hyphens, where they go. For example, it wouldn't break my heart if we got rid of the rule that you don't hyphenate "adverb-adjective noun" when the adverb is a regularly-formed "-ly" adverb (and this one is explicitly stated in the MoS).
 * But only very rarely is it justified to hyphenate on the right, because that's the way modifiers associate naturally. --Trovatore (talk) 08:21, 24 April 2011 (UTC)

Hadamard's lemma
Regarding the article on Hadamard's lemma. It is presented as a first order application of Taylor's theorem; which is fine. But then it assumes that the function is real valued. I'm sure that it works for functions from C to C. Moreover, I'm sure that the statement can be generalised in terms of other fields. Does the statement holds for functions from a field K to a field K? If not, then what are the necessary conditions? What is the most general form of the lemma? All we need is for a function from K to K to be continuous, and for its first order derivative to be continuous. I've listen to talks about p-adic differentiation and integration (i.e. where the field K is a finite field with a prime number of elements); surely the article can be extended. What do we think? — Fly by Night  (  talk  )  21:40, 22 April 2011 (UTC)


 * Over the complex numbers, the result is a trivial consequence of analyticity. I don't know about other fields.  In order to define smoothness, some valuation is presumably needed.  But (as far as I know) in the general setting of ultrametric fields, the theory of integration is either unsatisfactory or not really connected with the notion of differentiation, so the proof given in the article probably fails in that case.  But, as I know very little about ultrametric analysis, it could be that the theorem remains true even in that case.  However, that's far from obvious to me and would need a reference.   Sławomir Biały  (talk) 20:41, 23 April 2011 (UTC)


 * The article's proof doesn't carry over. Consider f(x) = xp over a field of positive characteristic p.  One of the first steps of the proof is to differentiate the given function, and when we differentiate f, the result vanishes.  The proof then relies on the integral of the derivative being the original function up to a constant, but this is not true.  I'm guessing that one could replace the f(a) term in the statement of the theorem with a function whose derivative is identically zero, and while I'm not an expert the result looks plausible to me.  It could also be that there's a different proof that gives a stronger result, perhaps even the same result as over a field of characteristic zero.  But again, I'm out of my depth here. Ozob (talk) 01:37, 24 April 2011 (UTC)


 * True, but theorems have more than one proof. Just because a certain proof fails to adapt to a given setting doesn't mean there is no other proof. As I said, and Sławomir implied, the result is a specific case of Taylor's theorem. We just need to understand what C1(K,K) means for different fields K. It's obvious over R and C (maybe over H too), and I feel that it may be meaningful over Qp where p is prime. Like I said, I have heard people talk about p-adic calculus. For example, the first hit on Google was this: p-Adic Calculus and its Applications to Fractal Analysis and Medical Science — Fly by Night  (  talk  )  01:45, 24 April 2011 (UTC)


 * The statement of the Hadamard lemma isn't quite a special case of Taylor's theorem. Nothing in Taylor's theorem (for several variables) guarantees that the remainder terms will be smooth near the expansion point, and I think that's the subtle point of the Hadamard lemma.  In fact, the Taylor remainder terms are non-unique, and we can always make them nonsmooth by subtracting some nonsmooth quantity from one and adding a balancing nonsmooth quantity to another (e.g., $$x^2 + y^2 = x^2(1+|x|y^2) + y^2(1-|x|x^2)$$).  I agree that it is a consequence of one of the most common proofs of Taylor's theorem, with the explicit integral form of the remainder, but this proof fails in the ultrametric case.  If there is a way to get it from Taylor's theorem directly, then that would probably go a long way to establishing it in that case.   Sławomir Biały  (talk) 02:11, 24 April 2011 (UTC)


 * Does anyone have any ideas as to how to overcome these obstacles? — Fly by Night  (  talk  )  22:21, 26 April 2011 (UTC)

Quasisymmetric map
In the article titled quasisymmetric map, this is given as the definition:
 * Let (X, dX) and (Y, dY) be two metric spaces. A homeomorphism f:X → Y is said to be η-quasisymmetric or if there is an increasing function η : [0, ∞) → [0, ∞) such that for any triple x, y, z of distinct points in X, we have
 * $$ \frac{d_Y(f(x),f(y))}{d_{Y}(f(x),f(z))} \leq \eta\left(\frac{|x-y|}{|x-z|}\right). $$
 * $$ \frac{d_Y(f(x),f(y))}{d_{Y}(f(x),f(z))} \leq \eta\left(\frac{|x-y|}{|x-z|}\right). $$
 * $$ \frac{d_Y(f(x),f(y))}{d_{Y}(f(x),f(z))} \leq \eta\left(\frac{|x-y|}{|x-z|}\right). $$

What does $$ |x-y| $$ mean? Does it mean $$ d_X(x,y) $$? Clearly the article needs work. Michael Hardy (talk) 15:11, 26 April 2011 (UTC)


 * I am pretty sure that is what's meant, though I'm no expert. I've changed the article accordingly. Ozob (talk) 23:11, 26 April 2011 (UTC)

Template:Cubes proposed for deletion
The Template:Cubes has been proposed for deletion: cubes Please see the discussion regarding its deletion.

Also, consider expanding and improving the Cubes navbox, which was recently created and newly expanded: In particular, crystallography may have many cubic articles. (It was never meant for mathematicians, who are served by the fine navboxes on polytopes, etc., but for civilians.)

Thanks! Kiefer.Wolfowitz (Discussion) 17:14, 22 April 2011 (UTC)
 * A confession: The former line of "ominous cubes" having the Klee-Minty cube, the Hellraiser cube, and the Cosmic cube was asking for deletion. Kiefer.Wolfowitz  (Discussion) 17:20, 22 April 2011 (UTC)
 * The navbox has been deleted. (An archival copy is on my talk page). Kiefer .Wolfowitz 22:43, 27 April 2011 (UTC)

Shapley–Folkman lemma Review for A-Class
The article Shapley–Folkman lemma has been nominated for A-class review. Your comments are most welcome. Best regards, Kiefer .Wolfowitz 22:58, 27 April 2011 (UTC)

Math contests medalists (was Peter Scholze at AfD)
The article Peter Scholze is at AfD: Articles for deletion/Peter Scholze. What do we think of this? (Initially I had missed that he was a Clay fellow, but this could tip the discussion the other way.)  Sławomir Biały  (talk) 13:14, 28 April 2011 (UTC)

Another IMO related AfD discussion is here: Articles for deletion/Iurie Boreico. This one seems more clear-cut. Sławomir Biały (talk) 19:46, 28 April 2011 (UTC)


 * There's also Gabriel D. Carroll and Reid W. Barton to consider. I see that Barton is notable for other stuff as well, and survived an AfD. Tijfo098 (talk) 03:28, 29 April 2011 (UTC)

David Rees (mathematician)
Can someone knowledgeable in commutative algebra add the details about Rees' contribution form some math source (and not a newspaper obit of someone else)? I've added the semigroup theory stuff I knew of. Tijfo098 (talk) 02:01, 29 April 2011 (UTC)

Also the page of his (former) student Michael P. Drazin could enjoy more than a sentence. Tijfo098 (talk) 02:05, 29 April 2011 (UTC)

90-degree rotation in the complex plane
New article looks like it was done as an extra credit project. Well done for what it is but not really encyclopedic in style. Copy to WikiBooks?--RDBury (talk) 04:12, 29 April 2011 (UTC)


 * Certainly the textbook style is more appropriate to WikiBooks. I have prodded it. Gandalf61 (talk) 08:28, 29 April 2011 (UTC)

multiplicative calculus
Does anyone have some details on Volterra's role in developing multiplicative calculus and to what extent this was influential? The impact of this subject seems to be not much greater than non-Newtonian calculus (see deletion page). Unless we can justify it as a historical page, it may be next. Tkuvho (talk) 04:58, 24 April 2011 (UTC)


 * My impression is that some people actually study this. But that could be because I've come to associate the moniker of "multiplicative calculus" with things like the product integral.  I've not made any systematic effort to locate sources for this article that are independent of the (clearly WP:UNDUE) Grossman and Katz book, and the few other questionable sources listed there.  It could go either way for me.   Sławomir Biały  (talk) 13:55, 29 April 2011 (UTC)

Monty Hall problem
Since the arbitration committee ruling, Monty Hall problem has become a much more cooperative place. Alas, it has also become a place where there are very few editors. If you walked away from the article because of the battleground it became, you might want to consider revisiting it. Guy Macon (talk) 12:52, 25 April 2011 (UTC)


 * Should it be added to the list of common misconceptions? Tkuvho (talk) 14:00, 26 April 2011 (UTC)


 * That's a really good question. My first guess is no, based upon what I perceive (but cannot prove) as a failure to meet the "common" criteria. I would guess that most people have not heard of the Monty Hall problem.  Totally subjective opinion, of course. Guy Macon (talk)


 * If the Parade magazine got 10 thousand protest letters, it is safe to assume that a much larger figure are aware of the problem, making it "common". Tkuvho (talk) 04:38, 27 April 2011 (UTC)


 * Agreed. CRGreathouse (t | c) 16:24, 27 April 2011 (UTC)


 * Thanks. If we can have just one more editor interested I would take it up at the "list".  A few editors there are (rightly) making sure there are no irrelevant additions, and it would be helpful to have the support of the project.  The "list" carries heavy traffic (tens of thousands of hits per day sometimes), and gives nice exposure to an elegant math problem (hope I am not offending anyone at WP:probability).  Tkuvho (talk) 08:59, 28 April 2011 (UTC)
 * I support in principle, but the current article has POV tag on top due to years' long disagreement between the regulars as to which solution is wrong. More appropriately add it to WP:LAME for now. Tijfo098 (talk) 06:18, 29 April 2011 (UTC)


 * I have added a non-controversial entry on Monty at list of common misconceptions that both sides should agree on, see there. Tkuvho (talk) 11:36, 29 April 2011 (UTC)


 * The delete elite troops are at work already at list of common misconceptions. Tkuvho (talk) 13:34, 29 April 2011 (UTC)

To Tkuvho: Rather than put the Monty Hall problem specifically into the list of misconceptions, you should figure out what general misconception about probability or statistics is responsible for the popular misunderstanding of MH and put that into the list. Then MH could be linked to as an example. That would make the entry much more useful and important. JRSpriggs (talk) 13:49, 29 April 2011 (UTC)


 * There is no way of sourcing such "generalisations", and they will certainly be rejected by the troopers. Actually, I disagree with the philosophical thrust of your remarks: the best way of explaining a misconception is by an example, not by discussion of general misconceptions that one thinks people have.  At any rate, the recent reverts are by an editor who... has a misconception about Monty Hall Problem!  See talk there.  Tkuvho (talk) 13:52, 29 April 2011 (UTC)

Category:Non-Newtonian calculus
Do we need Category:Non-Newtonian calculus ? Tkuvho (talk) 08:14, 29 April 2011 (UTC)


 * No, I don't think so. Neither do we need List of derivatives and integrals in alternative calculi. Ozob (talk) 10:20, 29 April 2011 (UTC)


 * I think I complained originally about that article looking like it was generated by a program rather than summarizing any source. I see the creator was banned so perhaps a simple prod will get rid of it now. Dmcq (talk) 12:05, 29 April 2011 (UTC)


 * Whatever material is appropriate for Product integral should be moved there. Tkuvho (talk) 12:12, 29 April 2011 (UTC)


 * It's hard to see what possible reference use such a table could serve. The sources are a bit dodgy, and do not seem to support the contents of the table.  A prod on OR grounds might prove uncontroversial enough.  I agree with Tkuvho that some material should probably first be merged to product integral, since that article would benefit from a few choice examples. However it seems silly to attempt any kind of list or table of such integrals, given that the product integral can be obtained easily from the ordinary integral.  Sławomir Biały  (talk) 13:52, 29 April 2011 (UTC)


 * I don't know much about product integrals, but with scalar-valued functions you can reduce their evaluation to that of ordinary "sum integrals". My understanding is that the thing that prevents that reduction from making the subject unworthy of further attention is product integrals of matrix-valued functions.  With matrix-valued functions you can't just reduce them to sum-integrals that way.  But there's nothing about product integrals of matrix-valued functions in the article.  If someone is knowledgeable in that area, that material should be added. Michael Hardy (talk) 04:29, 30 April 2011 (UTC)