User talk:Charles Matthews/Archive 10

This is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page.

Archive 5

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Archive 8

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Q-analog(ue)s

I really like the new limit information you put in Q-analogs. Also: sorry I switched Q-analogues to Q-analogs; I'm just starting to learn the rules around here. Vince Vatter 15:11, 20 Apr 2005 (UTC)

OK - we try not to let those spelling things become a big deal. Charles Matthews 15:14, 20 Apr 2005 (UTC)

Antipopes in fiction

I think it is a good idea. When I started fr:Wikipédia:Pages à supprimer#Antipape Benoît XV et Antipape Benoît XVI, I didn't have the idea for fr:Antipapes imaginaires, but I immediatly approved the idea when the page was created, because thse explanations were, in my opinion, "encyclopedical". I enjoy that other have the same opinion for the English WP... :o) Hégésippe | ±Θ± (French User talk page) 14:16, 23 Apr 2005 (UTC)

Taman Universiti Edit

I saw your edit on the Taman Universiti wiki which I've just started. Do you actually know the town or you're just editing the page for the sake of better English? Whatever it is, thanks for updating it, as the English sounds much better now.

Just a copy edit, really: I did add something about the location. I look at many newly-created pages. Charles Matthews 10:02, 24 Apr 2005 (UTC)

questions about sheaves

As you seem a specialist on this...

when one speaks of "restriction morphisms", is it right that they must respect the whole structure of the considered category? I.e., for a sheaf of topological algebras, they must be continuous algebra morphisms? (It seems to me that some authors disagree about that, maybe without noticing it...)
concerning gluing axiom (maybe), I understand (I hope) that e.g. the factor space of sheaves of, say, vector spaces (or algebras modulo sheaf of ideals etc) is in general only a presheaf. Is there a "feasible" condition allowing to say (in favourable cases) when the factor presheaf will be a sheaf, without need of the "full sheafification process"? — MFH: Talk 19:55, 11 May 2005 (UTC)

Not such a specialist, and it was a long time ago. First question: probably the wrong kind of question really. Though I can imagine such sheaves easily enough, and the only sensible answer would be 'yes, use only morphisms good in the category'. For the second, the formulation is wrong? One wants to have an abelian category of sheaves, so that there must be a notion of kernel, quotient. Perhaps the right question is formulated more like: how to describe the quotient in more elementary terms? For example, at the level of stalks.

Charles Matthews 20:03, 11 May 2005 (UTC)

Thanks for your answer. (although I don't understand what you mean by "wrong kind of question" and "the formulation is wrong?" - so for the moment, I won't meditate about that, maybe it will become clear later on... - maybe its also a confirmation of what I'm actually exactly talking about.)

1st point: I'm coming to this from an area of functional analysis where quotients of product spaces are considered. I'm running across lots of papers where the authors give themselves quite some pain in assuming (and stating the technically involved) "additional assumptions" making "everything work", because they take granted only the purely algebraic properties of the restrictions (vector space or algebra morphisms), but these additional assumptions just amount to continuity of the restrictions. (Often people using sheaf concepts (to define singular support etc.) are pure analysts that do everything by calculating majorations for some complicated integrals, and they don't really exploit the full-fledged category theory language.)
2nd point: here again, kernel and quotient are in those papers taken in a purely algebraic (i.e. set theoretic) way, i.e., they write for example

Let

\Omega \to A(\Omega )

be a sheaf of algebras, and

\Omega \to I(\Omega )

a sheaf of ideals of A. Then we have a the factor presheaf

\Omega \to F(\Omega )=A(\Omega )/I(\Omega )

...

So you agree that this is not correct? (I'm not sure if you get what I mean... e.g., as I understand, "sheaf of ideals" means for them just: for each Ω, I(Ω) is an ideal of A(Ω), and elements(functions) therein can be restricted to subsets of Ω. Whereas I think there is quite a bit more to it.) — MFH: Talk 17:13, 12 May 2005 (UTC)

I think I should maybe write up the exponential sheaf sequence, as a good example of exact sequences. There it is just a matter of expressing how logarithms work in the complex domain. The exactness on stalks is simple to understand. The corresponding sequence of sections is not exact, over non-simply connected sets; so you can't just take quotients on the section level. Charles Matthews 21:32, 12 May 2005 (UTC)

I agree on both points. Indeed, the exponential is a good pedagogical example. I think this really helps to understand the meaning of sheaf morphisms. Please do it! — MFH: Talk 22:40, 12 May 2005 (UTC)

Category:Laws of thought

Could I get you to edit this category (which you created) and add some text explaining what it's for? Its purpose is less than obvious. ----Isaac R 02:38, 20 May 2005 (UTC)

generalized functions

Please have a look at my critics on Talk:Generalized function. (I'm sorry in case it would seem unpolite, which was not intended at all.) — MFH: Talk 14:44, 23 May 2005 (UTC)

red links

maybe some of your "red links" could be "eliminated" by a more or less adequate redirection. Are you generally in favour of this, or rather prefer the "red link" as indicator that something has to be done ? — MFH: Talk 19:00, 23 May 2005 (UTC)

Wave front

What did you mean to redirect Wave front to? Currently it redirects to itself. Broken Segue 23:16, 23 May 2005 (UTC)

certainly wavefront, I fixed it. (could also be Lars Hörmander's wave front set used in microlocal analysis, currently redirecting to wavefront, which is an error). — MFH: Talk 21:48, 24 May 2005 (UTC)

I'm aware that wave front set as used in mathematics is not just the thing in Huyghens' principle; but it is not disjoint from it either (cf. the Guillemin-Sternberg book Geometric Asymptotics, where there is some statement of the HP as 'functoriality of the wave front set'). So, while the physics concept does not contain the full value of the mathematics concept, I think 'error' is too strong. Charles Matthews 11:11, 25 May 2005 (UTC)

Of course there's some "common idea" (whence Hörmander's choice), but on wavefront no bit of information can be found for s.o. looking for the definition (or even basic idea) of the wave front set. — MFH: Talk 21:01, 25 May 2005 (UTC)

Thanks for putting the [ [ ... ] ] at the right place (cotangent bundle vs WF set) on my new article about wave front set. However, I'm not so happy about your other edits. Please see Talk:Wave front set. — MFH: Talk 12:47, 26 May 2005 (UTC)

Woods hole fixed point theorem

Hello. You seem to have put a link to this not-yet-existing article into fixed point theorem. Can you tell me what this theorem is? I can't help but think of the Woods Hole Oceanographic Institution and wonder if there's a connection? Michael Hardy 01:51, 24 May 2005 (UTC)

It was a version of the Atiyah-Bott fixed-point theorem that was worked out at a conference at Woods Hole some time in the early 1960s. I believe, though I'm not an expert, that it is the case of the later theorem where the fixed point set is a discrete set of points. It has some historical importance, in that Goro Shimura has (IIRC) complained that the later full publication didn't properly credit the WH discussion. I read about it once in a duplicated set of conference notes, but I think they were not published in book form. The reference is there as a kind of sop to NPOV. Charles Matthews 11:08, 25 May 2005 (UTC)

Covariant Coordinate System

In general there is no such thing as a "Covariant Coordinate System" . In what physicists call "flat space" (probably an "affine manifold" for math guys), you can indeed define such a system in coordinate systems with straight axes (for example, Cartesian, or skew-Cartesian). In curved manifolds you are generally not so lucky. As I have remarked before in some of these discussions, the contravariant coordinate differentials are perfect differentials. Thus their integrals are unique labels for points and can be used as coordinates. In curved spaces (nonzero Riemann tensor) you can't integrate the covariant components of the differentials of the coordinates to get coordinates. The integral is in general path-dependent so you do not get a unique label for a point. Consider, for example, the sphere, using spherical polar coordinates. Let the polar angle be theta. The differential of the azimuthal angular coordinate is d_phi, and is the increment of change in angle round the polar axis. Its integral is phi, a coordinate. The covariant equivalent is r^2 sin(theta)^2 d_phi (using simple Tex-like notation.) You can't integrate that one to get a coordinate, and using a different coordinate system will not help (using the intrinsic geometry of a sphere - if you jump to 3-d space you can do it by reverting to rectangular coordinates, but that's not the game). If you do happen to think you can integrate r^2 sin(theta)^2 d_phi consider doing it along a parallel of latitude, and then compare going toward a pole along a meridian, along a parallel to the new theta, and then down to the latitude at which you started. The sin(theta)^2 makes the answer less when you use such a path. I suggest you remove that stuff about covariant coordinates or restrict it to rectangular and affine coordinates in flat spaces. Sorry.Pdn 02:49, 28 May 2005 (UTC)

I don't really understand what you are arguing here. Certainly dx is an exact differential (perfect differential, as you would have it. But in 'curved spaces', i.e. manifolds, there is a perfectly good notion of coordinate system, i.e. a chart. That's quite independent of any metric notions. Charles Matthews 13:18, 28 May 2005 (UTC)

Sorry - I fixed up some thetas and phis above. I will look up "chart" if I can find it. I agree that there is a good coordinate system in all the smooth spaces I know of, although of course it can be multiple-valued in ways we can handle (such as an angle whose range we restrict). May I ask for a simple example of a curved manifold with that you call a "covariant coordinate system?" Thanks Pdn 14:42, 28 May 2005 (UTC)

The meaning I'm using is chart (topology). I would never talk myself about a coordinate system as covariant. On a manifold one has various kinds of vectors and tensors, which may be covariant or contravariant. The difference is like this: take the Earth's surface: latitude and longitude give a satisfactory way of setting up a coordinate system anywhere (excluding the North or South poles). A vector field is something like what would appear on a weather map with arrows for the horizontal wind velocity. 'Dual' to that one has isobars. So I see all these as distinct concepts. Charles Matthews 14:54, 28 May 2005 (UTC)

In the changes to [1] on 27th May at 10:57 AM I believe you wrote "In tensor analysis, a covariant coordinate system is reciprocal to a corresponding contravariant coordinate system. Expressions for lengths, areas and volumes of objects in the vector space can then be given in terms of tensors with covariant and contravariant indices." This material disagrees with my conception and with your statement a few lines up (on this talk page):"I would never talk myself about a coordinate system as covariant, " unless there is a Wiki software glitch. Please state which one you mean. Thanks. I don't mean to be picky but I want it all to be crystal clear.Pdn 17:05, 28 May 2005 (UTC)

To clarify, I didn't write that. I merged it in from the contravariant page, in creating the new covariance and contravariance page, from the bits and pieces on this topic. Of course it all needs work now. Charles Matthews 18:57, 28 May 2005 (UTC)

I also do not understand your remarks about winds being "dual" to isobars. Generally, winds flow more or less parallel to isobars due to geostrophic effects [2] except at the equator. I think maybe you meant "orthogonal" by "dual" but as I say, that's not so for the winds. Anyway, you are talking abut vector (or tensor) fields defined on a manifold, I believe, while before you were onto the coordinates. In two dimensions you may "luck out" in finding integrals of vector fields that can be used as coordinates. ("coordinates" can't be multiple-valued except trivial cases like angles, where you can pick a principal branch). In more dimensions, the issues fall under those of "Pfaffian differential forms" and theorems due to Caratheodory [3]. In other words (within my limited understanding of the mathematics and of what you are trying to say with your "dual" field), the dual exists only locally and trajectories of the dual field cannot be used as level-surfaces or coordinate lines in curved spaces of dimension > 2.Pdn 17:58, 28 May 2005 (UTC)

Well, I was trying to talk in lowbrow terms, since you asked for a 'simple example'. I'm not quite sure in what register to conduct this discussion. You are quoting something like the Frobenius theorem to me. Of course I was simply using the isobars as a kind of 'orthogonal trajectory' way of describing duality. We can drop the whole business - obviously I'm not talking about geostrophic effects. This is about discussing what is covariant and what is contravariant, I imagine. (Pfaffian) differential 1-forms are contravariant, as the dual kind of field to a vector field. Charles Matthews 18:57, 28 May 2005 (UTC)

Grand - I understand and will love to drop it, too. It is unfortunate that the inadvertent copying of "covariant coordinate system" triggered my interest. Yes, the celebrated theorem of Frobenius is probably more relevant than Caratheodory's work, which I was recalling from about 1953, when I read Margenau and Murphy's "The Mathematics of Physics and Chemistry". Pdn 15:41, 29 May 2005 (UTC)

policy on deleting material from talk pages

Dear Charles, Is it acceptable to delete material from a talk page if it raises an issue that has obviously been dealt with in a satisfactory way? The example I have in mind is the "I have a minor beef..." paragraph on the Galois theory discussion page. You may answer in the affirmative by simply deleting this question from your talk page. Thanks Dmharvey 15:56, 30 May 2005 (UTC)

On the whole transparency is valued more than brevity. That is, most people much prefer talk pages to remain complete until they can be archived. The default is simply to leave things. By the way, hello, and thank you for your contributions. Charles Matthews 15:58, 30 May 2005 (UTC)

OK. You're welcome. This whole wikipedia thing is quite interesting, and I am enjoying myself, though I anticipate it becoming a real timesink. (Especially since the server seems very slow at the moment.) Hmmm. I have been astonished how many outside websites are copies of the articles in wikipedia. Some without ascribing any credit it seems. (Or perhaps wikipedia is not always the original source?).

One thing I am finding very difficult in the maths articles is gauging audience level. I have read the discussion on this topic on the wikiproject mathematics page, but I'm still finding it very difficult. For example, I just reworked the introduction to elliptic curves. The problem there is that the technical definition (which may be useful for a mathematician) is very short, and so I feel can be placed profitably in the opening paragraph. On the other hand, it is complete gobbeldygook for anyone without the background, so I provided a second definition which hopefully a high school student could get something out of, but which is in many ways quite misleading. But then we haven't covered elliptic curves defined over a scheme...! At some point I have to stop trying to cram more advanced versions into the introduction, but I'm not sure where that line should be drawn; it is not clear to me in the elliptic curves article whether I have pushed it too far, or whether it has not gone far enough. Do you have any favourite articles that you think succeed in addressing the multiple-audience problem?

I don't think we really have a solution to writing our intros. Like some other things, it may have to wait for a much more sophisticated set of page meta-data: so you could read the high-school intro or the math major intro or the physics professor intro ... Contemplating that, one sees that there is no real solution, beyond showing some good will towards the reader. Charles Matthews 21:29, 30 May 2005 (UTC)

long-term of future of mathematics in wikipedia

I am wondering what your opinion is of the possible long-term future of maths in wikipedia? In particular, do you think that wikipedia (or some other wiki-based medium) has the capacity to (eventually) become an authoritative source on well-understood material? I guess 'authoritative' and 'well-understood' are somewhat rubbery terms. For an arbitrary starting point, perhaps 'well-understood' might mean "material that has made it into book form by 2005", and 'authoritative' might mean that a professional mathematician might consider making WP their first port of call for learning material they are unfamiliar with. I appreciate your insight, you seem to have had a lot of experience on WP. Dmharvey 17:21, 30 May 2005 (UTC)

To try to sum up my take on this - mathematics is short of good survey articles, and not really short of textbooks, except for things that are quite recent. It is quite hard to get a good historical perspective, from the technical literature alone; and much harder to understand what is going on in the Russian or Japanese perspectives, than in Paris or Princeton. We ought to be trying to give a good broad coverage, by survey article standards, with reasonable references. We ought to be giving the sort of background that makes the current preprints more accessible (so, basic definitions to answer 'what the hell is X?' questions). We should reach for a good overview of the whole tradition, and what is going on globally. I don't think it is so sensible to aim to compete directly with the conference literature, say. WP ought to complement academia, and make the effort to explain 'how it all fits together' and 'why any of this matters' - which academics generally don't find the time for. Charles Matthews 21:01, 30 May 2005 (UTC)

Interesting. (BTW thanks for your time in answering these questions; you must be a pretty busy guy.) I certainly agree with your last sentence, i.e. that WP should help explain 'how it all fits together', I'm very keen on that. I'm also very keen on giving historical perspective. On the other hand, it seems that WP provides an ideal vehicle for a piece of writing to start off as a survey article, but then slowly morph into something providing textbook level detail, while nevertheless remaining a survey article to a reader not concerned with details or proofs. (They just don't have to follow all the links.) Mathematics seems to be a subject area especially suited to this, since there tends to be less disagreement about correctness than in most other academic discplines.

I'm sure this meta-wiki discussion has been had by plenty of people already :-). Perhaps I should spend some time reading what everyone else has had to say. As I am a wiki newbie, I am probably suffering from some kind of wiki-thrill, believing that WP can solve all of humanity's problems. It does seem to me to be a genuinely new form of communication/publishing media, which as you can tell I find very exciting.

WP can do some good, no question. Trying to audit quite how much progress is interesting, taxing and sometimes chastening. The first five years, for mathematics, is going to look like 10000 pages with much 'core' material. Chronologically the solid coverage can get us into the 1950s, mostly; but not past 1960. I would project, that in 2010 it would look more like 1970 rather than 1960; and even that is ambitious and would require much more expertise in the 'rarer' topics (algebraic geometry and topology, for example) than we currently command. I'm quite upbeat, but it is still very easy to find the gaps. Charles Matthews 10:13, 31 May 2005 (UTC)

Hi Charles, Dmharvey. I don't mean to butt in on this conversation, but I've enjoyed reading both of your thoughts in this and the above section (the "multiple audience" issue particularly), and I would expect others involved in Wikipedia:WikiProject Mathematics would find these discussions interesting and beneficial as well, and perhaps even want to join in ;-) However if you prefer to keep this a private discussion, I respect that. Paul August ☎ 15:13, May 31, 2005 (UTC)

As far as I'm concerned, I'm not saying anything private - go ahead, Paul. Charles Matthews 15:27, 31 May 2005 (UTC)

Charles, yes, I didn't really think that what you were saying was meant to be private (I was just trying to allow for the possibility that you or Dmharvey might prefer to have a two-person conversation). And anyway there isn't anything I really want to add to the discussion — yet. I just think that you guys have been having a couple of interesting discussions that others would be interested in also. So I was trying to encourage you to consider discussing these ideas on Wikipedia talk:WikiProject Mathematics. (By the way thanks for your vote in support of my admin nomination ;- ) Paul August ☎ 16:45, May 31, 2005 (UTC)

As far as I'm concerned, nothing on WP is private :-) (Unless of course you're using PGP, but that, as they say, is just not cricket.) I'm quite happy for anybody to move the above text to an appropriate venue, or to do whatever is appropriate. Dmharvey 18:22, 31 May 2005 (UTC)

VfD's on Japanese articles...

Superset is this vfd, they are listed individually in that VfD as well. FYI. I voted keep. Wikibofh 04:32, 3 Jun 2005 (UTC)

Thanks for the alert - I'm only sporadically online today. Charles Matthews 15:45, 3 Jun 2005 (UTC)

Japanese fascism seems to be by the same author; see Wikipedia:Votes for deletion/Japanese fascism. Did you try / manage to come into contact with the author? -- Jitse Niesen 01:14, 17 Jun 2005 (UTC)

I've created a customized cleanup template, and gone through every article in your list and added it. Hope you don't mind. I'm hoping it will head off VfD. You can find it on the bottom of my userpage if you want to cut-n-paste it. Wikibofh 03:59, 17 Jun 2005 (UTC)

My personal interest in Japanese side and motives to sended japanese informations

In first place,i sended my great agreed for your understanding respect at my attempts of sended information,still my limits in idiom.

i when see your intense cleanups,observed why this information no losses the principal escense of this,at contrary are convert to interesting and easy to read(how poses sources i can to compared and never seeing any change in roots of ideas in these dates)

Reiterally i no poses any imagination or great capacity to inventive for created all type of cyphers or social and military details,more less inside of japanese side or from these times. these information are only knowed in detail any person why living in these moments or stay in somes forgett history old books of 40 or 60s editions in english.

for other Hand the Lingua franca,if for suppose the English and the best experts in materia or the more detailed research groups or discusion or analisis tables in topic,if obviously in english too. in other idioms this information are more short,limited or never exists,only in english...

i am poses personal interest in topic: i poses any japanese ancestor (little merchant),i poses present japanese friends,i knowed of relate of oldest parents why theirs during wartimes knowed some japanese fishers why result ones japanese agents with short wave radios and responsed to Japanese Navy superior.theirs stay relationed with Japanese special plan of I-400 subs and i read of Japanese order to Sub I-9 to patrol waters surrond U.S.Panama Canal.

in personally i sende more hate for statisticts or numbers or any cyphers groups,or all great mass of dates,but over my typical hate or disdain at statistics or great mass of dates i stay identified with Japanese side ,for all decided to sended this information,

this if my principal founts of my incredible,highly questionable or very dudous information over General Japanese civil and Military comments:

General sources:(oldest editions of 40s to 60s)

Cressey,G.B.Peoples and lands of Asia
Scion,Jules. Asie des Moussons(english edition)
Behr,Edward.The Last Emperor
Book Asia,the great Continent
Newman, Joseph. "Goodbye Japan"
Whitney Hall, John."Japanese Empire"
Gonzales-Hontoria,M.African and Asian States(Estados Asiaticos y Africanos)

over Chinese japanese War comments if my sources:

Max,Alphonse.Southwest Asia,Reality and Destiny.
American First-hand and Chinese side relate "China In Weapons" or "China in Arms" about chinese-japanese conflict.

reiterraly my great agree with you.

by 200.46.215.181

Hello there - I haven't been on Wikipedia recently, and have only just read your message. It saddened me to see the difficulties you sometimes had with your contributions. For myself, I appreciate your efforts to expand these areas of Wikipedia. Charles Matthews 19:10, 24 Jun 2005 (UTC)

Forgive me for intejecting. I saw some of your articles before. Your motives are admirable; and it is understandable that you do not speak English well. I would like to ask you just a small favor. Could you please put a space after comma, that will be so helpful. And if you make an account, it will be easier for us to track what you write. To return you the favor, I voted against deletion of those articles. Oleg Alexandrov 03:56, 10 Jun 2005 (UTC)

Cubing the cube

Should the last sentence of the last paragraph of "Cubing the cube" read "that is, given a cube C, to divide it into finitely many smaller cubes, no two congruent," instead of "not all"? —Sean κ. + 17:04, 18 Jun 2005 (UTC)

Since you're a Go player...

Since you are one, take a look at WikiGo and tell me what you think, or possibly participate. Thanks! -- Natalinasmpf 16:03, 20 Jun 2005 (UTC)

Thanks for the additions

Thank you for the corrections and additions of categories to the pages on Fermat's Christmas Theorem. They were both my first effort at a wiki page, and I did not know how to add the categories at the bottom of the page. And now I discover I don't know how to put my name at the end of these things... Arturo Magidin June 28, 2005, 12:20 (MDT).

Category:UK Wikipedians

Hi, just to let you know that the list of UK participants at the UK notice board was getting rather long, so I have replaced it with the above category which I have added to your user page. -- Francs2000 | Talk 30 June 2005 18:58 (UTC)

You rock

Thanks for being such a great encyclopedia editor. ¸,ø¤º°`°º¤ø,¸¸,ø¤º°`°º¤ø,¸¸,ø¤º°`°º¤ø,¸ 1 July 2005 00:00 (UTC)

Plead for help on gender categorizaton

Greetings. I think there should be a couple of more people in the discussion that has arised over gender categorization, specifically female categories. Maybe you could take a side, whichever it be? Please see this discussion and the dscussions of other categories nominated for deletion that day. Maybe there should be a general conclusion on this topic, to avoid future debates? Note that categories such as Category:Women composers have already been deleted, but that List of female composers exists. Also of analogical relevance is Wikipedia:Categories_for_deletion#Category:People_by_race.2Fethnicity_and_all_subcategories. Karol July 1, 2005 07:21 (UTC)

Let's work together

I saw you name on the history board for the decortive knotting in East Asia page, and I feel that page need a LOT more stuff about Chinese Knottingon it, which I know a lot about. How about we both work toghether on this whole article thing, shall we? -Andylandandrew

Brian's derivate

Hi Charles, could you please take a look at Brian's derivate. Looks like nonsense to me, but would like a second opinion before sending it to VfD or speedying it. Thanks, jni 9 July 2005 16:53 (UTC)

I stumbled across the above comment, I had a look at the article myself, and I listed it on VfD. I don't think it quite satisfies the "patent nonsense" criterion of speedy deletes. Apologies to Charles for taking away the satisfaction of VfD'ing the article :) -- Jitse Niesen (talk) 9 July 2005 18:44 (UTC)

Tree (descriptive set theory)

Hi, I thought the simpler intro was good, but the breaking out of TeX into separate lines was a bit overdone and interfered with the flow. My feeling is that the picture ugliness is a temporary problem pending full support for MathML, at which time it will be an advantage to have everything written in TeX in a more natural style.

On a separate note, why did you italicize (and bold) wellfounded and illfounded, while the other terms being defined were just bold?--Trovatore 06:12, 11 July 2005 (UTC)

Putting TeX as displayed rather than inline is the house style. Depending on one's browser, inline TeX can come out rather strange.

Compromise effort in place. Can you point me to a browser where it looks bad? --Trovatore 17:25, 11 July 2005 (UTC)

There's a very long (as you'd expect) discussion at http://en.wikipedia.org/wiki/Wikipedia_talk:WikiProject_Mathematics/Archive4%28TeX%29, which is (as you'd expect) inconclusive. I think we decided to concentrate on content rather than format, since too much time gets used up on minor stuff otherwise. The developers do a great job in propelling WP to ever more prominence, but the lag on the mathematics format is just something to live with. At least that's how I see it. Charles Matthews 18:10, 11 July 2005 (UTC)

The use of italics is a convention associated with saying 'called' in a definition. That is, apple is being flagged as a term defined. Normally we prefer the style 'an X is a Y that has property Z'; but in some circumstances it is OK to say 'an X with property Z is called a Y ... '; where the format is bold for highlighting a definition, plus italic for the used of 'called'. Charles Matthews 07:44, 11 July 2005 (UTC)

OK, but "illfounded" doesn't have the word "called" before it. What about "pruned" et al? Are they the same sort of thing? --Trovatore 17:25, 11 July 2005 (UTC)

So, I guess for consistency pruned would be better; for illfounded it is kind of implied, and it would I think look more pedantic, rather than less, to have it the other way. None of this is really a big deal, but it seemed worth going over what I understand to be our usual conventions. Charles Matthews 18:05, 11 July 2005 (UTC)

Sentence (mathematical logic)

So first, I find the phrasing

it follows that, considering model theory

to be a bit awkward. But more importantly, it seems that there are a couple of pages that use the phrase "model theory" to refer to the Tarskian notion of structure and satisfaction, which I don't think is standard usage. In model theory AUIU, you generally have a fixed complete theory in mind, and you're looking at properties of models of that theory (stable, superstable, homogeneous, saturated, etc). Somewhere there should be a page about the Tarski notion, and it shouldn't be called "model theory". Maybe "Structure (mathematical logic)"? --Trovatore 19:59, 15 July 2005 (UTC)

Well, I suppose it should somewhere go through the (standard?) idea of what it means to interpret things in a model. This is what I was alluding to. I don't think you need anything as serious as a complete theory? You just need to make the passage from syntax to semantics. Charles Matthews 20:05, 15 July 2005 (UTC)

I'm saying the prasing should be "interpret things in a structure", not "interpret things in a model". When I use the term "model", I have a theory in mind that it's a model of (you're right, not necessarily a complete theory). --Trovatore 20:10, 15 July 2005 (UTC)

Ah, well, I'm not a logician and I can't comment on what common usage is. You're probably right that strictly a model is some ordered tuple with a theory, a structure and whatever constants etc. one needs. Charles Matthews 20:14, 15 July 2005 (UTC)

Cambridge Mathematical Tripos

Para-academic? That's not even in the OED...

In my reading, the article suggests that the Tripos ended in 1909. Is that what you intended to write, and if so, what would you call the course that the current students are taking?

For the rest, great read, and a welcome distraction from the mess at Srebrenica massacre.

Cheers, Jitse Niesen (talk) 22:00, 15 July 2005 (UTC)

I've clarified a little what happened after 1909. The Warwick book is an interesting read; and it also does something to explain why my son still has to do some of those fiendish mechanics questions. Charles Matthews 07:34, 16 July 2005 (UTC)

verify

I saw you wrote "Sources, please" on a talk page. I added the below to the article. Just wanted to make sure you knew of this handy dandy label: {{verify}}. 4.250.138.52 11:03, 17 July 2005 (UTC)

I edited the post above so it wouldn't show up in the Articles which lack sources category. -- Kjkolb 05:34, 3 October 2005 (UTC)

moving articles

Please, when you are moving articles, as you recently did from Sort to Sort, Catalonia, use the Move function. Now the edit history is separated from the article it really applies to. -- Jmabel | Talk 04:06, July 19, 2005 (UTC)

Yet Another London Wikimeet

Heya,

We're organising another London meetup, for Sunday the 11th of September; specifics still to work out, but it will probably be fun as ever, and involve a few drinks and a nice chat in a pub. We'd love to see you there again...

James F. (talk) 22:08, 19 July 2005 (UTC)

Praise from the press

A journalist looked up Nicolas Bourbaki to test wikipedia and compare it to another encyclopedia, and was most impressed. Just thought you'd like that, seing you wrote much of the article. It's in rockymountainnews, on the web here (at the bottom of the article). Quote: "Whoever wrote it, t(he)y knew what they were talking about." Shanes 22:46, 26 July 2005 (UTC)

That's good to know. Of course it was written by many of us. I think the comments on Bourbaki's biases are particularly useful, since there are not many reasoned sources for this kind of thing. Charles Matthews 07:39, 27 July 2005 (UTC)

Multivalued function

When I was clicking to this article from function (mathematics) I became concerned that I was missing something fundamental in what I learned many years ago in Math 112. Imagine my relief when I read your May 28 2005 clarification of the historical usage of this term. When I started looking into the history for the culprit, it occured to me that this article and the function (mathematics) article may have been lifted from the 1911 Brittanica (which explains everything). I am hoping that the more modern definition of function is being used elsewhere. Didn't the term "set-valued function" replace Multivalued function anyway? Considering the fundamental nature of these and related articles, I am requesting a consensus before doing anything. Please advise. Vonkje 14:56, 1 August 2005 (UTC)

You could add to that article the remark that a relation can be written as a (partial) function to a power set. I wonder if it is worth trying to explain more? Charles Matthews 18:17, 1 August 2005 (UTC)

Just wanted to thank you ...

Hi! I recently went to have a beer with my fellow informatics university studentmates, and when I brought up the term "Wikipedia" they responded that they have been looking around on it, and the Maths part seems to be absolutely brilliant, with a wide range of stuff, all high-quality. So I just wanted to thank you for that, because as I can see, a lot of advanced maths has been done by you. I am sure others must be credited, too, but It seems like you have made an unusually large effort. (BTW: I live and study in Hungary, so knowledge passes boundaries) Thx again --Msoos 22:06, 1 August 2005 (UTC)

What can I say? Thank you for the encouragement. Charles Matthews 22:07, 1 August 2005 (UTC)

Takeuti conjecture

Our paths haven't crossed in quite a while: nice to run into you again! You put the Takeuti conjecture stub into Category:Conjectures: does it really belong there? The conjecture has been settled for almost 40 years, though it is still called the Takeuti conjecture in the proof theoretic literature. --- Charles Stewart 16:05, 4 August 2005 (UTC)

I think so. The list of conjectures has four categories, and it would fall in the first. Category:Conjectures could be likewise divided, but not so far AFAIK. Categories IMO are more about navigation than about comment. Charles Matthews 16:08, 4 August 2005 (UTC)

Move of Inclusion (mathematics) to Inclusion map?

Hi Charles. Since you were the creator of both these pages I though I would let you know that I am proposing moving Inclusion (mathematics) to Inclusion map. For my reasons and how I plan to go about it see Talk:Inclusion (mathematics). If you have any thoughts on this move please comment on that talk page. Thanks. Paul August ☎ 03:40, August 12, 2005 (UTC)

User_talk:Rangerdude#I_am_a_Yankee.2C_but_not_the_sort_you.27d_think...

I need your help to clarify to others on the nature of English rule of themselves and their battles with the Welsh/Scottish Briton dynasties of the post Plantagenet world. There is a dearth of knowledgeable people with a sincere interest in the legitimate history of New England. Bigelow 03:41, 18 August 2005 (UTC)

Gel'fand-Naimark theorem

Hi Charles. If you feel strongly about it, by all means restore the title but please save the no-apostrophe version as a redir. Usually Russian "ь" (мягкий знак, the soft sign) after letter "l" doesn't get into English translation because English "l" is already softer, but I guess in this case it's a matter of tradition and I won't insist on breaking it. ←Humus sapiens ←ну? 08:04, 4 September 2005 (UTC)

Another mathematician

Charles, I've noticed your conversation with Gauge at the Chern page. I have written an article about his colleague, Jim Simons, who co-authored the paper which resulted in the Chern-Simons theory.

Simons' article could use some attention in two areas: organizing his acedemic credentials, both as a student and faculty, and double-checking to make sure the mathematical "things" described in the article are worded correctly, and meaningfully. I'm essentially the only author of the article up until now. Although you might not be familiar with this man, your expertise may come in handy to these specific areas.

I hope you find the subject interesting.

Regards,

paul klenk 09:21, 6 September 2005 (UTC)

I've gone through making some changes in the style. Charles Matthews 15:11, 6 September 2005 (UTC)

can you check out the article on quasiperiodic ...

... and add whatever definition that you see fit (from quasiperiodic tiling or whatever)? i put the Planet Math stuff in there, but i know less about that than i do about the DSP, audio, and music synthesis meaning of the word. r b-j 08:59, 11 September 2005 (UTC)

Science pearls

Hello,

Since you contributed in the past to the publications’ lists, I thought that you might be interested in this new project. I’ll be glad if you will continue contributing. Thanks,APH 11:11, 11 September 2005 (UTC)

quadratic integral

Please see talk:quadratic integral. Maybe I'll be back. Michael Hardy 00:57, 20 September 2005 (UTC)

Koszul complex

I was linking the Lie algebra cohomology article to Koszul complex and noticed that you contributed an intro to the second article stating that it was invented for the purpose of defining a theory of Lie algebra cohomology. I am curious about more of the history of this, do you know of an article or reference? (BTW I have not used a talk page before, if this is not the correct use feel free to let me know). Kinser 02:46, 20 September 2005 (UTC)

Well, it would be Jean-Louis Koszul's thesis, I guess, around 1948? Early Bourbaki seminars cover it. Charles Matthews 10:25, 20 September 2005 (UTC)

Gillian Rose

Hello Charles, I'm just wondering how in the world two people as diverse as us have managed to work (in little steps) on the Gillian Rose entry. Best,Tom

Hi there. I work on many things, some of which I have a clue about, others (especially in the humanities) where I'm very much a learner. Charles Matthews 09:12, 29 September 2005 (UTC)

Hello to you

Thanks for your message. We all have our own styles. There's nothing to stop you editing articles and removing links you don't like! Best wishes. Poetlister 21:41, 2 October 2005 (UTC)

Bounded operator

Hi Charles, could you please have a look at Talk:Bounded operator where a statement (linear transformations with Banach spaces as domain and range are bounded) is challenged which you appear to have written originally. I think the counterexample is not in fact a counterexample, as I explain on the talk page, but I don't feel confident enough to remove the disputed template myself, since I could not convince myself that the statement is correct. Cheers, Jitse Niesen (talk) 17:31, 5 October 2005 (UTC)

Yes, I understand what is being said there (a discontinuous linear functional). Charles Matthews 07:34, 6 October 2005 (UTC)

Wikimedia UK meeting

Hi Charles, there will probably be a meeting for the purpose of discussing Wikimedia UK this Sunday, which you may want to attend. You could add your name there if so. Cormaggio ^@ 23:23, 5 October 2005 (UTC)

WP:CP

Hi, you've reported copyright infringements to WP:CP in the last week, a new measure was recently passed to allow the speedy deltion of new pages that are cut and paste copyvios. Please follow these instructions if you come across this type of copyvio. Thanks. --nixie 00:23, 6 October 2005 (UTC)

Blatant copyright infringements may now be "speedied"

If an article and all its revisions are unquestionably copied from the website of a commercial content provider and there is no assertion of permission, ownership or fair use and none seems likely, and the article is less than 48 hours old, it may be speedily deleted. See CSD A8 for full conditions.

After notifying the uploading editor by using wording similar to:

{{nothanks-sd|pg=page name|url=url of source}} -- ~~~~

Blank the page and replace the text with

{{db-copyvio|url=url of source}}

to the article in question, leaving the content visible. An administrator will examine the article and decide whether to speedily delete it or not.