User talk:Gro-Tsen

Hi there! On the kind of point you're raising about algebraic geometry pages - it seems fair to say that we are short of experts on all the main divisions of pure mathematics for the last half-century. That is, getting past 1950 or so is always quite tough, given that the basics have to be built up from scratch. So please don't feel inhibited about adding material. As they say, be bold!

The one point I would make is that it is all incremental. There is no real answer to the question 'how many types of scheme need a mention?' Maybe if the abelian variety coverage were built up, it would be one thing; if we started to have some singularity theory, or moduli space articles, or more coherent cohomology discussed, other things. I'm sure you get the point - in the end it should add up to something much more integrated, but it works out that additions are always piecemeal.

Charles Matthews 22:00, 16 Feb 2004 (UTC)

Don't bother with the translation French-English, just write the French page, and I'll translate (Tu pourrais aussi faire l'inverse, mais je ne sais pas si t'as confiance dans mon français). Schopenhauer 18:40, 17 Feb 2004 (UTC)

On ordinal numbers

To Gro-Tsen: Regarding your changes to the ordinal number page on March 6, 2006. 1. "so-called" seems to denigrate "well-order", which I feel is inappropriate. 2. I cannot imagine that a good mathematician would confuse ordinals with well-orderings of other sets. 3. Using "$\omega \cdot \gamma$" leaves omega in an italicized form which is inconsistent with the rest of the article where the ordinary form of omega is used for the least infinite ordinal. 4. Why make a temporary definition? Just say that the (real) definition is below. 5. "lexicographically" is a good edit. -- JRSpriggs on March 6, 2006

(1) The reason for the "so-called" is to make it clear that the intro (but only the intro) of the ordinal number article ought to be understandable by a reader who does not know what a well-ordered set is. So what I mean to say is "a certain structure which is called well-ordered sets, for which we refer to another article but which the reader need not know about for the moment". I don't think "so-called" is derogatory, and I can't find a better way of conveying the meaning I intend to convey (but if you can think of such a way, do state it).

(2) I consider myself a mathematician: I don't know about "good", but I don't think I'm suggesting this confusion out of incompetence. Seriously, the point is that while it makes sense to distinguish isomorphic objects when the isomorphism is not canonical (e.g., to speak of an algebraic closure of a field, rather than the algebraic closure), in the category of well-ordered sets all isomorphisms are unique, so the distinction between two isomorphic well-ordered sets can be considered hair-splitting. (Of course, when the well-ordered sets have some extra structure such as being subsets of some larger set or something of the sort, then the distinction needs to be made. But my point is that just as one tends to disregard the distinction between Z/2Z and any "other" group with two elements it is a reasonable abuse of language to consider any well-ordered set of type ω to be ω. Naturally, we aren't really "confusing" the sets, we just let canonical isomorphisms left unstated. Such a point of view is common in category theory, and set theorists of course do not have a monopoly on ordinal numbers.) But, more to the point, from the pedagogical point of view I think the remark is worth making, because I've already noticed that some beginners manage to grasp one of the concepts of "ordinal" and "well-ordered set" without understanding the other, which is strange: so this note is supposed to help them realize that they should transfer their understanding from one to the other. Again, if you feel strongly, try to suggest a way to rephrase this. But remember the intro is supposed to be mostly pedagogical (more than the rest of the article, at least).

(3) We should check in the manual of style, but I'm pretty sure we're not supposed to mix HTML markup with LaTeX-style markup. Remember that LaTeX-style might be rendered as MathML (using BlahTeX or whatever) and I don't think it likes this sort of mix. If you write ω·<math>\gamma</math>, someone set preferences to display even simple equations using PNG images will see the gamma as an image and the omega as text, which is worse than the problem you describe, I think. Now maybe we <math> should have been used all the way along, I don't know.

(4) Well, I don't care much about that one, really, so you can change it back if you really care. I just wanted to make the point that, for many purposes, one doesn't need to know what ordinal multiplication is in general, merely left-multiplying by ω is enough, and it just amounts to indexing the limit ordinals.

--Gro-Tsen 11:43, 7 March 2006 (UTC)

OK. I let you have 2,3,4. And I will try to reword 1 ("so-called"). JRSpriggs 10:10, 8 March 2006 (UTC)

I just read the Wikipedia article on Cofinality; and it supports my version of cofinality as including 1 as the cofinality of a ordered set with a greatest element in the set. So I am tempted to remove the qualification from the revised subsection on cofinality. Do you agree? JRSpriggs 07:13, 10 March 2006 (UTC)

Tell you what. I will just take out the qualifications. If you disagree, you can revert it to the version I created yesterday. JRSpriggs 09:38, 10 March 2006 (UTC)

I like your additions to "cofinality". JRSpriggs 10:32, 12 March 2006 (UTC)

Oppose plan to move "Ordinal number"!

Some people are planning to move the article Ordinal number. Since you were once very active in editing this article, I would hope that you would express your opposition to this disasterous idea at Talk:Ordinal number#Should the article really be called transfinite ordinal numbers. JRSpriggs 07:30, 8 September 2006 (UTC)

To be honest, I don't care very much. That is to say, I very mildly agree with you that the article shouldn't be renamed, but not enough to enter the "tempest in a teapot". If it comes to a vote, I'll cast a weak one, but so long as it's just a debate, I'll leave it at that. It's a shame, though, how much time can be wasted by people who want the naming of the articles to be absolutely perfect, when that time could be spent by actually writing useful articles. --Gro-Tsen 08:59, 9 September 2006 (UTC)

Fair use sur fr:

Bonjour, j'ai parcouru rapidement les pages de cette prise de décision, et je n'ai pas l'impression que vous y ayez donné votre avis. Je ne conteste pas que vous soyez plus intelligent que les autres contributeurs de fr:, mais d'autres personnes pourraient en douter, donc ce serait bien que vous donniez vos arguments (si vous l'avez déjà fait et que ça m'a échappé, pouvez-vous me dire où vous avez abordé le sujet ?). Apokrif 18:11, 28 December 2006 (UTC)

WikiProject France

Hello! We are a group of editors working to improve the quality of France related articles. You look like someone who might be interested in joining us in the France WikiProject and so I thought I'd drop you a line and invite you! We'd love to have you in our project :-) STTW (talk) 15:02, 14 January 2007 (UTC)

CN Tower

The Sky Pod is NOT the higher level. The "official" CN Tower page is wrong. Please see the talk page. Maury 23:02, 19 March 2007 (UTC)

quine

You're right. After I submitted it, I realized my comment was off, but the actual text I added was correct and helpful, so I left it.

Mathematics CotW

Hey Gro, I am writing you to let you know that the Mathematics Collaboration of the week(soon to "of the month") is getting an overhaul of sorts and I would encourage you to participate in whatever way you can, i.e. nominate an article, contribute to an article, or sign up to be part of the project. Any help would be greatly appreciated, thanks--Cronholm144 21:35, 13 May 2007 (UTC)

Guayaquil conference

Thanks for calling me a vandal.The reason why i deleted that paragraph is that a touristic webpage with a section of summarized history and a webpage of some argentinian guy is not enough reference to make such a claim agaisnt Bolivar.Besides the short story of Borges you mention about the conference makes me think that your view of the subject is heavily based on that story(after all Borges was argentinian).So i will delete the paragraph again unless its better referenced.--Andres rojas22 22:11, 3 June 2007 (UTC)

see the article talk page--Andres rojas22 00:05, 4 June 2007 (UTC)

"Debt Money"

Hi, how can it be that the sole authors of this page are fringe kooks? What can be done about it? I don't know enough either to attempt to fix it. The current guy seems to think also that "free speech" is something he should have on wikipedia, for his "position". 32F 14:35, 20 September 2007 (UTC)

I don't know where else to add this, but I have to say I am very shocked by this page. I have heard some people complain about how bad Wikipedia was, but although I use it a lot I have never found a page that really disturbed me that much. Occasionally a few errors (for example, as a mathematician you would appreciate that someone had mixed up "stronger" and "weaker" in the discussion of computational reducibilities, and I fixed that one), but nothing really totally beyond the pale. And that there is some guy who is totally unreasonable about pushing his fringe point of view and blaming objections on the fact that "the truth hurts". Oy. 32F 14:39, 20 September 2007 (UTC)

I think the best think to do is try to bring the dispute to other (hopefully more reasonable) people's attention. I tried to do this by posting on Wikipedia:WikiProject Business and Economics, but there may be better ways. Also, the debate should be focused not on whether the article is right or wrong, but on whether it's neutral or biased (and in this respect there's no reason to ask for qualifications). As for how bad Wikipedia can be, that's an unfortunate truth we have to live with: marginal and little-read article are often used as tribunes for crackpots; we can fight them to some extent, but we'll never be rid of them, and we just have to develop the eye to recognize that sort of things. --Gro-Tsen 14:42, 20 September 2007 (UTC)

I agree: as I have constantly been pointing out to the fellow, the main point is that it is not neutral. The criticisms are pretty lame, but if framed correctly, I at least believe, there is a non-negligible grain of truth to them. I also added a few cross links (in discussion pages on Monetary theory and the disputed page. Not as rational as your links: I (ashamed to say) never really thought before about the issues of "projects" and the tools available for trying to coordinate them. Thanks for the lesson there. 32F 15:11, 20 September 2007 (UTC)

Veblen ordinals

In your definition of the small and large Veblen ordinals in large countable ordinal you seem to have an extra Ω in the tower of exponentials. I'm not sure whether this is a misprint or just notation I am unused to. R.e.b. (talk) 18:42, 5 March 2008 (UTC)

Sorry, I remember looking it up, but I can't remember where: I remember having had to convert from a different notation to the one used in the article (something like a different $\psi$), and it's quite conceivable that either I made the conversion incorrectly or else the definition of the function $\psi$ was changed in the article (I seem to remember not throwing in the Veblen functions, but I may be confusing with something else). arXiv:math/0509244v2 gives a definition which may or may not be complete — incidentally, I notice that it makes a difference between the Ackermann and small Veblen ordinals. Anyway, I apologize if I made a mess, and I'll be grateful if you can sort it out. --Gro-Tsen (talk) 20:27, 5 March 2008 (UTC)

As a start to clearing this up, I've removed the claim that the Ackermann and small veblen ordinal are the same until I can find a definitive statement about this, and replaced the definition of Veblen ordinals with a link to Veblen ordinal (where they are not yet defined....) R.e.b. (talk) 21:43, 5 March 2008 (UTC)

Incidentally, if you can keep a uniform function $\psi$ across articles for impredicative-beyond-the-Veblen-function-induction, and, even better, if you can keep it as simple as possible (as in: one variable only), it would be great! --Gro-Tsen (talk) 11:03, 6 March 2008 (UTC)

Sure; unfortunately I havnt yet found such a definition of the veblen/ackermann ordinals, and the current "defn" is a temporary fix until I find one. Translating between different systems is dangerous (and a violation of WP:V). There just doesnt seem to be any generally accepted standard notation for impredicative ordinals; if you have any suggestions let me know. R.e.b. (talk) 15:55, 6 March 2008 (UTC)

Your latest contribution to Secession hall (Austria)

Hi there,

I saw your latest contribution to Secession hall (Austria) and I want to say thanks. Are you into numismatics? It would be great to get help (of any sort) to finish building Euro gold and silver commemorative coins and their respective sister articles, all referenced from the one I just mentioned. Please take a look and be welcome to contribute if you feel like to.

Thanks, Miguel.mateo (talk) 01:43, 14 August 2008 (UTC)

Question

Is there an expression for constructing the countable ordinal expressing the consistency strength of ZF in terms of the size of the smallest countable transitive model of ZF? Should they be equal?Likebox (talk) 00:09, 29 October 2009 (UTC)

No, they are not equal. The ordinal expressing the consistency strength of ZFC (or “proof-theoretic ordinal” of ZFC, whatever the exact definition) is recursive (it can be explicitly defined as some relation on the natural numbers—or proofs or whatever—which ZFC is ever-so-slightly-too-weak to show is a well-ordering): hence it is less than the Church–Kleene ordinal. On the other hand, the smallest α such that $L_{\alpha }$ is a model of ZFC, albeit countable, is (“considerably”) larger than the Church–Kleene ordinal, because the latter is the smallest α such that $L_{\alpha }$ is a model of a much weaker fragment of set theory, Kripke–Platek set theory. You won't get a much more precise answer than that, because the proof-theoretic ordinal of ZFC is far beyond any reasonable description in terms of, e.g., collapse. However, if you ask the exact same question for Kripke–Platek instead of ZFC, then both ordinals can be described: the proof-theoretic ordinal of KP is the Bachmann–Howard ordinal and the other is the Church–Kleene ordinal as I just said (and a collapsing function gives a sort of connection between the two, at least in a loose sense). --Gro-Tsen (talk) 20:44, 31 October 2009 (UTC)

Your bio article

I didn't know you edit here, or I would have contacted you first as a courtesy. I hope you take no offense, but I found your bio article here troublesome on a somewhat subjective level too in that it portrayed you (picture included) as "nerdy prof that designed an obscure language", which is why I nominated it for deletion from the sea of other stubby biographies. Like I wrote in the AfD nomination, a lot of the articles here were created before we had any guidelines for what is a reasonable topic for an article, and a lot of the articles were created by the geeks that were early adopters of Wikipedia before those guidelines were written. I don't like the (mis)use of the word "notability" to describe what is or isn't a reasonable topic for an article, but it's entrenched here. Nominating your bio for deletion doesn't mean I think your not notable in the plain English sense of the word.

As for unlambda, which was actually how I found your bio, it is the subject of some independent commentary, all of it found and added to that article by me. Even though there is little independent coverage, I'm not going to nominate it for deletion because I think it's a weak keep based on those sources, but others like RDBury might think otherwise.

There's no rule here that the existence of an article on some language/software automatically requires a biography article for the author. I prefer that some independent coverage of the author exist as well, e.g. Werner Lemberg is a little stub I created because I stumbled on an interview with him; admittedly I was too lazy to write more about him from that source. On the other hand I didn't create a biography of Till Tantau, even though we have articles on Beamer (LaTeX) and PGF/TikZ (created by me) because I couldn't find any secondary source that covered him in some depth. Articles based exclusively on people's resumes are prone to original research and balance issues, because some Wikipedia editors would have to go trough the resumes and pick the stuff that they consider important for the bio article. The resume can be used to fill out some details, but I hope you see why some anonymous blokes on the internet selecting someone's major achievements directly from a resume is a process fraught with problems. No source other that the wiki article up for deletion identified you as "the guy famous for creating Unlambda". (Strangely enough none of the three sources used in the Unlambda article even mentioned you by name; well, one of them has your name in an URL...) Pcap ping 05:09, 31 December 2009 (UTC)

I just wanted to add that notability standards for biographies of living persons (WP:BLP) are, in general, more stringent than general notability guidelines, partly for the protection of the subjects. It sometimes happens that a person who is not otherwise a public figure has been the subject of a Wikipedia article and has complained about invasion of privacy or that the article is the subject of vandalism. As for the unlambda article, to me the notability guideline for mathematics and related areas is very simple; if a subject as a non-trivial appearance in an independent, reliable, secondary source (i.e. textbook or survey paper) then it is notable, otherwise it isn't. This criterion does not attempt to gauge the importance of a subject, nor should Wikipedians be involved in making this determination. The consequence of this is that many important ideas in the literature are not currently notable since it takes time for textbooks to catch up with active research, but this is to be expected given the scope that Wikipedia has set for itself as a tertiary source. In effect, Wikipedia is relying on the assumption that if a subject is important enough to be notable in the ordinary sense of the the word, then it will be noted, i.e. it will eventually appear in a secondary source and become notable in the Wikipedia sense.--RDBury (talk) 14:27, 2 January 2010 (UTC)

RfD nomination of ΤΕΧ

I have nominated ΤΕΧ (edit | talk | history | protect | delete | links | watch | logs | views) for discussion. Your opinions on the matter are welcome; please participate in the discussion by adding your comments at the discussion page. Thank you. — the Man in Question (in question) 07:50, 6 January 2010 (UTC)

I spent some time searching for the RfD, but apparently you removed it. --Gro-Tsen (talk) 00:35, 7 January 2010 (UTC)

Pendantic question

Hi, I had a quick question about your recent edit to the Special Drawing Rights page. You changed "anodyne" to "innocuous" saying the former was not appropriate. Why doesn't "anodyne" work?

It means, according to oxforddictionaries.org, "not likely to provoke dissent or offense; inoffensive, often deliberately so". Innocuous means "not harmful or offensive".

Wouldn't anodyne be the better word in context, as the SDR was deliberately given an inoffensive name. Fleetham (talk) 23:13, 8 August 2011 (UTC)

My dictionary only gave the definition: "serving to assuage pain; soothing", with examples only from medicine (plus the poetic "the anodyne draught of oblivion"), so I assumed other meanings were rare—and in any case it's probably best to avoid words that many readers will have to look up (when they're not germane to the topic of the article). But if you think it should be reverted, I won't argue either. --Gro-Tsen (talk) 05:23, 9 August 2011 (UTC)

No need to revert. English has too many weird, seldom-used words: abstemious, anathema, antipodal, bailiwick, coruscant, dudgeon, exculpate, flense, houri, imprecate, lionize, miasma, micturate, opprobrium, psychopomp, traduce, etc. etc. Fleetham (talk) 06:14, 9 August 2011 (UTC)

Your recent edit to "Ordinal collapsing function"

Your recent edit to Ordinal collapsing function#Beyond the Feferman-Schütte ordinal produced several bold red error messages (at least in my browser). The first of these reads "Failed to parse (Missing texvc executable; please see math/README to configure.): \psi(\Omega^\Omega+\Omega^\alpha) = \phi_{\Gamma_0+\alpha}(0)". What gives? JRSpriggs (talk) 09:26, 16 February 2013 (UTC)

It was just a server bug. I had noticed it and hoped it would merely go away with time (or be visible only to me): since apparently it didn't, I made a trivial change to the page to force recompilation of TeX formulæ, and apparently that worked. --Gro-Tsen (talk) 10:49, 16 February 2013 (UTC)

Thank you. JRSpriggs (talk) 02:27, 18 February 2013 (UTC)

My explanation of the Feferman-Schutte ordinal

Hi, in case you missed it, here's my attempt at an explanation of the Feferman-Schutte ordinal: http://en.wikipedia.org/wiki/Talk:Large_countable_ordinal#Questionable_assertion_about_Predicativity Tell me if you have any questions. 69.248.132.69 (talk) 22:31, 17 December 2013 (UTC)

Mirror symmetry article

Hello,

I noticed that you're a member of WikiProject Mathematics and that you've expressed interest in algebraic geometry. I wanted to let you know that the article on mirror symmetry is currently a featured article candidate.

If you're interested, we'd love to hear your thoughts on this page. Please note that you do not need to be an expert on the subject.

Thanks for your help!

Polytope24 (talk) 18:40, 22 March 2014 (UTC)

Added chapter parameter

Please review my edit. I added chapter parameter. Feel free to revert me if you do not agree with this change. -- Magioladitis (talk) 11:53, 28 July 2014 (UTC)

ArbCom elections are now open!

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