Wikipedia talk:WikiProject Mathematics/Archive/2006/Jun

message: My knowledge of Lie algebras is a single course, but this potentially confusing notation was never mentioned. Has anyone else heard of this? Septentrionalis 18:40, 1 June 2006 (UTC)
replies: text: I have never heard of this notation.  I note that my references list the notation as E8(1).  The subscript here is, as always, the rank. -lethe talk [ +] 18:51, 1 June 2006 (UTC)
thread_title: [[E9 (Lie algebra)]]

message: I have extensively revised and cleaned up Divisibility rule, so please take a look and help to improve it more.  As I'm not fully experienced at all the editing tools, I'm sure the formatting and adherence to guidelines and standards could be improved.
I'd like to create a number of other pages related to mental math, so I'd like to get feedback on this one, the first I've heavily edited.  (The current mental arithmetic has only the most basic, simple of techniques.
Walt 01:59, 2 June 2006 (UTC)
thread_title:  Please review 

message: See Wikipedia:Categories_for_deletion#Category:Thousand. Oleg Alexandrov (talk) 18:57, 3 June 2006 (UTC)
thread_title: [[:Category:Billion]] and cousins up for deletion

message: Some Chinese news sources have picked up a story about a recent journal article by Cao and Zhu, experts on the Ricci flow, who have written what they (and the journal editors) claim is a "complete" proof of the geometrization conjecture, by giving more details of Perelman's work.  Slashdot has also picked up on this.  As a consequence, there has been several editors who have insisted on placing mention of Cao and Zhu's paper in the lead section.  I have disagreed (see talk page discussion and also some of my edit summaries for extensive reasons).  Please continue discussion there.  I would also appreciate if people could pop in and check that things don't get out of control.  Thanks.  --C S (Talk) 02:15, 6 June 2006 (UTC)
thread_title:  [[Poincaré conjecture]] 

message: The article on American Institute of Mathematics has been nominated for deletion by someone. R.e.b. 13:02, 6 June 2006 (UTC)
thread_title:  American Institute of Mathematics 

message: The PlanetMath Exchange project has today reached a new milestone, with 40% of all PlanetMath articles reviewed.
For those of you who have not been following the project, I thought I would take this opportunity to report on the status of the project, and the progress which has been made to date. The purpose of the project is to review all PlanetMath (PM) articles (which are licensed under GFDL) and to incorporate any appropriate PM content not adequately covered on Wikipedia (WP).
There are over 4800 PM articles listed, of which over 1900 of which have been reviewed so far. Of the reviewed articles, 143 PM articles have been copied to WP, creating entirely new WP articles,  and 121 have been merged into already existing WP articles. Additionally, a further 75 PM articles have been identified as needing to be copied, and 349 needing to be merged.
The project maintains 49 lists of PM articles grouped by topic (e.g. 11 Number theory, 26 Real functions, 54 General topology). The entire list of lists is compiled into a "Article lists" table, and statistics are maintained for each topic's list.
19 editors have identified themselves as participants, and 26 have reviewed at least one PM article (see Editor contributions).
Oleg Alexandrov, has provided several excellent tools to facilitate the project. He and  Mathbot created the original 49 lists (first created in Feb 2005, and updated with new PM articles in March 2006). They also perform daily updates of statistics in the "Article lists", and "Editor contributions" tables. In addition, Oleg has created a convenient tool to assist in converting a PM article to wiki markup.
I heartily encourage everyone to join the fun.
Paul August ☎ 02:06, 8 June 2006 (UTC)
thread_title:  PlanetMath Exchange project milestone 

message: See Wikipedia:Articles_for_deletion/Direct_logic -Dan 15:36, 8 June 2006 (UTC)
thread_title:  [[Direct logic]] up for deletion 

message: Please vote at Wikipedia:Articles for deletion/American Institute of Mathematics. Michael Hardy 23:33, 9 June 2006 (UTC)
replies: text: Yeah, R.e.b. told us already. -lethe talk [ +] 00:48, 10 June 2006 (UTC)
replies: text: I closed that AfD. -lethe talk [ +] 00:54, 10 June 2006 (UTC)
thread_title:  Another misguided nomination for deletion 

message: Hi, I left a question regarding the correct statement of the Ryll-Nardzewski fixed point theorem at Talk:Ryll-Nardzewski fixed point theorem. Cheers, AxelBoldt 04:10, 11 June 2006 (UTC)
replies: text: As stated it's wrong. The semigroup is  required to satisfy another property, that it be "distal". Also I don't think it can be used to prove existence of Haar measure on general locally compact groups, although I think for compact groups yes.  I think this is in Rudin's functional analysis book for instance.  Also see Frederic Greanleaf's little book (now horribly outdated) on "Amenable Groups".--CSTAR 12:41, 12 June 2006 (UTC)
thread_title:  Functional analyst needed 

message: I invite interested parties to make comments at Talk:Poincaré_conjecture#Peer_review.  --C S (Talk) 12:48, 11 June 2006 (UTC)
thread_title:  Rewrite  [[Poincaré_conjecture]]? 

message: An anon recently redirected the wikilink in Chaos Theory from the first to the second.  Is this legitimite?  Are these the same person?  — Arthur Rubin |  (talk) 15:30, 11 June 2006 (UTC)
replies: text: Yes, same person. Correct spelling is Jacques . I have changed the Jaques page to a redirect and fixed the link in the single remaining article that used the wrong spelling. Gandalf61 15:53, 11 June 2006 (UTC)
thread_title:  [[Jaques Hadamard]] or [[Jacques Hadamard]]? 

message: I wanted to  this article. But to be sure I thought I'd check. Is this article nonsense or not? I couldn't google the name, but that doesn't always mean anything. Garion96 (talk) 00:20, 12 June 2006 (UTC)
replies: text: The theorem and its proof in the article are correct. The theorem was not known to me under this or any other name. --LambiamTalk 00:53, 12 June 2006 (UTC)
replies: text:  Thanks, so I won't  it. Anyone here wants to clean that article up? Cause the way it looks now, it's not understandable for the non mathematician reader. Like me. :) Garion96 (talk) 12:04, 12 June 2006 (UTC)

text:  Hmm, perhaps I should have looked at at the article again. It already is cleaned up. Thanks. Garion96 (talk) 12:05, 12 June 2006 (UTC)
replies: text:  I think it's a neologism. I think it should be deleted without some evidence of that name having widespread currency. Dmharvey 12:15, 12 June 2006 (UTC)

text:  I've heard it referred to in that way ("zipper theorem"); dunno if that's enough evidence for you.  I also can't think offhand of a place I've seen it in print, though.  I could ask around.  Lunch 18:53, 12 June 2006 (UTC)

text: Merge it into Limit of a sequence#Properties?  —Blotwell 17:01, 13 June 2006 (UTC)
replies: text: I've asked a few people around, and none other than me have heard this result referred to as the zipper theorem.  I guess it's not as popular a term as I thought.  Maybe zipper lemma instead?  ;)  Maybe it'd qualify for a list of some sort of elementary properties of limits; if not, maybe stick it in the article on limits.  BTW, this theorem is true for any metric space, but is it true for non-Hausdorff spaces?  How much can the requirements of the theorem be relaxed?  Lunch 21:57, 20 June 2006 (UTC)
replies: text:  The exact same proof, translating epsilons into open sets, proves it in every topological space.  This result has about the same significance as, say, the linearity of differentiation, and should probably go in a list of limits like the list of derivatives. Ryan Reich 22:48, 20 June 2006 (UTC)
replies: text: Sure, a list of limits article would be a good idea.  And I guess you can just replace balls with neighborhoods; I think I was confusing myself with the non-uniqueness of limits in non-Hausdorff spaces.  Lunch 23:33, 20 June 2006 (UTC)
replies: text: Sorry if I was curt with that reply.  I'll be happy to put together a basic list of limits.  Actually, following the model of the list of derivatives, there isn't any need to touch zipper theorem, just link to it from the list.  Unless we really don't like it for some reason. Ryan Reich 00:22, 21 June 2006 (UTC)
replies: text: looks good!  Lunch 17:58, 22 June 2006 (UTC)
thread_title:  [[Zipper theorem]] 

message: Over at Talk:Constant of motion, I've been reduced to babling and waving my hands to the effect that a "system of differential equations with constants of motion == integrable system == system with symmetries" and conversely, "non-integrable system == system with no constants of motion".  However, it occurs to me that I know of no grand theorems making this claim. Are there any?  Is this in fact a collection of small results in narrow fields that have accreted into a grand truth? Guidance? How can one make this clear at a college-math level? It doesn't help that the article integrable system is somewhat foreboding in its current form. linas 01:30, 13 June 2006 (UTC)
replies: text: Maybe I'm being lame? Maybe its just the Frobenius theorem coupled to the idea that the submanifold has a natural symmetry, ergo by Noether's theorem has constants of motion? I've never had formal skoolin in this matter. linas 03:13, 13 June 2006 (UTC)
replies: text: I think I'm grasping for Liouville's theorem (Hamiltonian). I swear this stuff goes in one ear and out the other. I'm babbling even now. linas 03:27, 13 June 2006 (UTC)

text: Thanks. What I've been reading gives the name completely integrable system to the case of a full set of commuting Poisson brackets. Your "not being sure about the converse" would imply that there are non-integrable systems with a "full set" of conserved quantities. That certainly sets my mind wandering in wild directions. linas 23:27, 16 June 2006 (UTC)

text: Nice start on integrable systems.  It certainly has helped me organize some of my own wild wanderings.  I'm clearly not an expert, but it seems to be tricky to give a good definition of an integrable system.  (Ok, so first off, yes I meant what you call completely integrable: which is unarguably a better term ;)  In particular, there are issues of local versus global integrability.  What does global integrability mean anyway?  Do the all the level submanifolds have to be closed?  Do the constants have to be found explicitly, or can they just be given in some implicit sense?  Can a locally completely integrable system have degenerate Poisson brackets on some small dimensional locus, and still have functionally independent integrals?  (Here is the "lack of converse" possibility -- if it exists to begin with.)  Silly rabbit 23:37, 17 June 2006 (UTC)
replies: text: Thanks. I'd say a Lie group is the prototype for something that is "globally integrable". I don't know of any systems that are "provably integrable" (constants of motion implicitly given), but whose solution is unknown (no explicit form). I suspect one can find level manifolds that are not closed, certainly things like the horocycle flow ( aka Anosov flow on tangent space of SL(2,C)) has the flavour of being non-compact but this is an off-the-cuff remark. I believe that the whole area of sub-Riemannian geometry is permeated with integrable systems that have cuts and isolated singularities and the like. Next, chaotic systems have "regimes" of regular and chaotic motion that's interspersed; the KAM torus being the famous example, although the easy-to-understand variants are in difference equations. Then there's all this stuff about homoclinic orbits, and stuff like Axiom A, which I dimly understand. Or things I dont:Smale's spectral decomposition theorem. I'm sort of learning this stuff as I go along.linas 04:57, 18 June 2006 (UTC)
thread_title:  integrable systems 

message: Does WP have a glossary that translates the language of probability theory to measure theory? I've got a complaint on my talk page that I'm trying to decipher; I don't understand Score (statistics) and Fisher information, although I suspect I would, if they were restated in terms of measure theory.  The root of this interest is the rather astounding edit here, which is so remarkable, I abstract it here:
:Fisher information is a powerful new method for deriving laws governing many aspects of nature and human society. B. Roy Frieden sets out in detail how Fisher information can ground a great deal of contemporary physical theory, including Newtonian mechanics, virial theorem, statistical mechanics, thermodynamics, Maxwell's equations, Lorentz transformation, general relativity, EPR experiment, Schrodinger equation, Klein-Gordon equation, Dirac equation, Rarita-Schwinger equation, and the fundamental physical constants. Frieden and coauthors have also used EPI to derive some established principles and new laws of biology, the biophysics of cancer growth, chemistry, and economics.
Surely, the ommission of M-theory and intelligent design is just an oversight? linas 00:38, 17 June 2006 (UTC)
replies: text: See Talk:B._Roy_Frieden for a little bit of discussion and some links to external reviews of Frieden's work.  He has some interesting ideas but, it seems, not quite the revolution he makes out for himself.  The IP address of the edits is assigned to [http:/csc.canterbury.ac.nz Christchurch College of Education] in New Zealand.  Maybe Frieden's been travelling?  Lunch 03:49, 17 June 2006 (UTC)
thread_title:  Probability/Measure theory glossary? 

message: :(Copied from my talk page. Oleg Alexandrov (talk) 07:51, 17 June 2006 (UTC)
replies: text: There had been some noise in the past about moving propositional calculus to propositional logic or classical propositional logic.  The move to propositional logic was affected by Charles Stewart via WP:RM last month, then reverted by a history-destroying copy-paste by Jon Awbrey this week.  I reverted the copy-paste (restoring the history), then reverted the proper move (preserving the history), so now we're back where we started.  If the move is to happen, a case will have to be made again.  -lethe talk [ +] 07:59, 17 June 2006 (UTC)
thread_title:  Problems at Propositional Calculus 

message: Currently we have 12102 articles in the list of mathematics articles. Out of them, 1070 are redirects (see the complete list). Redirects get created in several ways
# Plugging in some redlink in the list (not anymore, as all redlinks are removed automatically)
# Merging an article to a bigger article
# Renaming an article.
In my view it is the third which makes for most redirects. 
While redirects are very important, I see no good reason for why they should stay listed in the list of mathematics articles (I estimate that there are at least 2000 math redirects which are not there). 
I wonder what people think of a big purge, removing all redirects from the list of mathematics articles. Of course, if at some point a redirect becomes back an article, my bot will add it back to the list. Thanks. Oleg Alexandrov (talk) 22:37, 17 June 2006 (UTC)
replies: text: So if I create a redirect to a math article, but the redirect isn't already a redlink from the list, then it doesn't get added to the list? -lethe talk [ +] 22:57, 17 June 2006 (UTC)
replies: text:  No. The bot adds to the list of mathematics articles via categories. So, if your redirect is made to be in a math category (which it won't, most of the time), the bot will add it to the list. Otherwise it won't. The primary purpose of list of mathematics articles is to list articles I think, not redirects, although a separate list of redirects to math articles may be found useful by some people. Oleg Alexandrov (talk) 23:55, 17 June 2006 (UTC)
replies: text: Well whatever uses there may be for a list of math redirects, this list cannot serve, since it doesn't contain them all.  Therefore, you have my full endorsement to remove them.  There is simply no reason to have only some of the math redirects in a list, right? -lethe talk [ +] 00:00, 18 June 2006 (UTC)

text: I'm not sure what purposes the list serves. Take Circular arc, which is currently a redirect to Arc (geometry), but the concepts are distinguishable and Circular arc might eventually grow into a separate article. In an index it would be reasonable to include it. If the purpose is to have a way to visit every maths article to check if its conforms to a new policy, then you'd prefer to skip it. (By the way, it currently is not categorized.) Perhaps math-categorized redirect pages could be listed, but rendered in italics, like with the All pages search. (<-This comment was by User:Lambiam who forgot to sign it. JRSpriggs 11:08, 18 June 2006 (UTC)
replies: text:  OK then, so if a redirect is important enough, it should be categorized, and then my bot will add it in. About making redirects italic, that is harder to do, as I would need to daily download a lot of articles to see which are redirects. Oleg Alexandrov (talk) 16:25, 18 June 2006 (UTC)
thread_title:  Redirects in the [[list of mathematics articles]] 

message: See here. I'm not precisely sure about terminology here, but perhaps this makes Jitse a Developer. This is good news, but I don't promise mathml tomorrow. Still some work to do. We'll keep you posted. Thanks guys for your encouragement, and especially lethe for the insistent emails on mediawiki-l :-) Dmharvey 12:00, 22 June 2006 (UTC)
replies: text: Or perhaps he's saying that he's responding to Jitse, and he will be adding the BlahTex extension (because he put in a comma).  Either way, its good. —Mets501 (talk) 12:35, 22 June 2006 (UTC)
replies: text: It only makes me a minor developer. The standard tariff is to sacrifice one virgin every full moon as otherwise Bad Things Happen. However, I can also be placated with papers on which I can put my name as co-author. ;) -- Jitse Niesen (talk) 13:19, 22 June 2006 (UTC)
replies: text:  Well, I can give away my virgin mathbot as a groom to the brand-new bride-to-be Jitse's bot (who am I am sure is a she, or otherwise can be made so just by flipping a bit). Oleg Alexandrov (talk) 16:10, 22 June 2006 (UTC)

text:  So who is "jitsenielsen" anyway? Dmharvey 14:11, 22 June 2006 (UTC)
replies: text:  I'm pretty sure Brion Vibber made a spelling error :-) —Mets501 (talk) 14:30, 22 June 2006 (UTC)
thread_title:  Some progress has been made 

message: Maybe this is not the place for this (I am aware that this is not un all-purpose forum), but here it goes. I intend to order some math books from Amazon, but I'm not sure what to get. As it seems to me that there are some very good mathematicians here, I think you could help me a lot with some recommendations. Now for some background, to understand what I specifically need: I'm an undergraduate math student (though also an economics graduate and working economist) and I pursue math mostly for my own curiosity and because I truly enjoy it (more than economics :D). I need something mainly appropriate for self-learning, so I'm targeting good classic texts on major fields or other good books. I prefer books that don't shy away from advanced/abstract concepts, but preferably give motivation for concepts and some intuitive explanaition/interpretation. Also, I learn the most from books which include examples worked-out in detail and/or solved relevant problems. Also, note that unfortunately cost is an issue, so don't recommend too many books that are only somewhat helpfull (though by all means recommend books that you consider good, even if they are not very popular). Hope that you will have some advice for me... AdamSmithee 20:48, 18 June 2006 (UTC)
replies: text: A great place to ask this question, which is indisputably appropriate (unlike here, which is apparently disputably so :)) is the sci.math newsgroup.  You can get there through Google groups if you don't already know.  This page is really just for discussing the Wikipedia mathematics project. Ryan Reich 20:57, 18 June 2006 (UTC)
replies: text: I am sure that we could give a great deal of advice (though some of us will contradict each other!), but we do need a bit more info about your mathematical interests and level: which branches of maths are you most interested in? what sort of level are you at in that level? Perhaps it might be best if you could tell us some maths books that you believe you have mastered, and we could suggest some books that would make a "good next step"? Madmath789 21:02, 18 June 2006 (UTC)
replies: text:  Myself, I'm a graduate student and I like algebraic geometry and sometimes number theory.  Or did you mean him? :) Ryan Reich 21:42, 18 June 2006 (UTC)
replies: text: LOL! I did mean 'him', but our edits crossed, and I got the indentation wrong :-) (but if you want some suggested reading on algebraic geometry, I can probably oblige :-) ) Madmath789 21:46, 18 June 2006 (UTC)

text: The most affordable route is used books, especially if you live in or near a decent university or college. Some of the much older books are easier to learn from, because not so long ago mathematics texts had a bad habit of being horribly written for learning, though packed full of detail for reference. More recently there may have been a corrective swing, so that one can benefit from both a modern viewpoint and decent pedagogy. But in a field like algebraic geometry, the really old stuff has lots of geometry while the modern stuff has almost none. Depending on your tastes, one may appeal more than the other. Another fact about older books is that often recent books try not to duplicate the work of the early masters, so if you want to get the original insights from the folks who had them you have to step back in time. It reminds me of something that was said about the programming language ALGOL, that it was an improvement on many of its predecessors, and also on many of its successors. Lastly, it is vital to choose books at the right level at the right time, lest an otherwise great book become a doorstop. --KSmrqT 22:39, 18 June 2006 (UTC)

text: Hi, I suggest browsing Dover Publications online catalogue (use Google to find, I am lazy :P). They republish a lot of classical and important texts. By rule of thumb, eastern Europe is more advanced in beggining of undergraduate studies. -- 127.*.*.1 01:14, 19 June 2006 (UTC)
thread_title: Request for book recommendations

message: I have just had a brief look at the page Poussin proof, and apart from being a short stub, at least half of it seems to be mathematical rubbish. I would like to have a go at making this into a sensible article - but about the Dirichlet divsor problem (the first sentence of the Possin page), as I can't find anything about this elsewhere. If I have missed it, and there really is a page about the Dirichlet divisor problem, plase let me know before I waste too much time ... Madmath789 12:11, 19 June 2006 (UTC)
thread_title: Poussin proof

message: As best I can determine, here is a list of the math-related articles that have been deleted. Birgitte§β has kindly restored them temporarily:
*Wikisource:Prime deserts  - a fairly short short list of gaps in the primes
*Wikisource:Fibonacci numbers 1-500    
*Wikisource:Mersenne primes - up to number 30, 2^132049−1
*Wikisource:Phi to 30,000 places - There was also an article listing Phi to 20,000 places
Also there were computer source code articles with the following titles:
*Wikisource:Fibonacci sequence          
*Wikisource:Euclidean algorithm    
*Wikisource:Prime factorization    
I'm not sure these have mcuch value. Finally, I believe there were once articles listing pi and e to a million places. These would be easy to reconstruct if anyone wants to make a case for them.
I think a case can be made for moving at least the first two or three articles above to Wikipedia, presumably retitled as "Table of..."  Comments?--agr 18:35, 20 June 2006 (UTC)
thread_title: Deleted math articles

message: The section Old Babylonian Mathematics (2000-1600 BC) of this article seems to be a copy of this page (starting with "Perhaps the most amazing aspect of ..."). It's especially funny in sentences like "In our article on Pythagoras's theorem in Babylonian mathematics we examine...", where in reality, no such article exists on Wikipedia. What should be done about it?
On a somewhat related issue, User:Chem1 has created the article Ibn al-Banna (1256-1321), to whom he attributes the invention of the iterative process x_{n+1} = \frac{1}{2}(x_n + \frac{N}{x_n}) for finding the square root of a number - aka the "Babylonian method". This doesn't seem right. -- Meni Rosenfeld (talk) 14:41, 21 June 2006 (UTC)
replies: text: I'll take a shot at a re-writing and wikifying the Old Babylonian Mathematics (2000-1600 BC) section. Gandalf61 14:54, 21 June 2006 (UTC)

text: I've removed that section from Babylonian mathematics as well as and following section as possible copyright violations, leaving a notes on the talk page of that article, and the editor who added it. Paul August ☎ 15:31, 21 June 2006 (UTC)
replies: text: Okay, I've now trimmed, re-written, wikified and re-ordered the offending section. I think it is now sufficiently different from the source to be no longer copyvio, so I have put the re-written version back into the article. Gandalf61 13:17, 22 June 2006 (UTC)
thread_title:  [[Babylonian mathematics]], [[Ibn al-Banna]] 

message: I've never poked my head into the Math WikiProject before, but a few months back I did some work on Fraction (mathematics) before I had to take a break to tend to both Real Life and my proper job.  Looking around, I can't help feeling there's a lot to be done, and it's not just a matter of the one article:
* If Vulgar fraction and fraction (mathematics) are not to be merged, then duplicate material needs to be excised.  If they are to be merged, then let's merge 'em!
* Fraction (mathematics), while slowly improving, needs cleanup, and needs it badly, but the lengthy material on the arithmetic of fractions really belongs in an article all its own.  Or, for that matter, in a Wikibook, but...
* the Wikibooks material is scant, sometimes incorrect, and things are often hard to find, or can be found in more than one place.  Looking for fraction arithmetic, for instance, I found it under both Algebra/Arithmetic and Applied Math Basics, but not under Beginning Mathematics.  Are Wikibooks out of the scope of this WikiProject?
* Amongst the mess, there's probably more duplicated material about Egyptian fractions than there needs to be.
I'd keep going, but another task is calling me from my PC.  I know that fractions might not be a hip'n'trendy subject, but I work as a tutor at a community college and there are a few math topics that come up a lot, and manipulating fractions is one of them. :) I'd be willing to take the lead on this, as long as I have the support of the Project. --Jay (Histrion) (talk • contribs) 21:09, 21 June 2006 (UTC)
thread_title:  Fraction refraction. :-) 

message: Wikipedia:Categories for deletion/Log/2006 June 23#Category:Degenerate forms Oleg Alexandrov (talk) 01:48, 23 June 2006 (UTC)
thread_title:  [[:Category:Degenerate forms]] up for deletion 

message: When I do "random article" I occasionally come across mathematical formulae (and sometimes with general science books etc). It would be useful for those of us who are not mathematically informed if there was a "basic explanation" as to use and purpose.
See the examples I put on Wikipedia:Requests for expansion for what I mean. Jackiespeel 16:54, 26 June 2006 (UTC)
replies: text: In reference to boolean-valued function, boolean domain, and finitary boolean function.  Those are pretty short stubs.  They need lots of work (or perhaps even to be merged somewhere).  In response to your general query: yes, I will try to make every math article I write have explanations, examples, context, and everything else that makes for brilliant writing.  Sometimes a stub is better than nothing though. -lethe talk [ +] 17:37, 26 June 2006 (UTC)

text: Finitary boolean function, Boolean domain and Boolean-valued function and some of the links thereof - can someone give an explanation in "ordinary English" as to what these functions are. I can see that they are complex mathematical functions - but "what are they"? Perhaps a brief standard text could be added. "This mathematical function is used in xxx, and does yyy." (add more detail as required) Jackiespeel 23:14, 24 June 2006 (UTC)

text: Finitary boolean function is not a generalization but a specialization of boolean function. The situation is a bit messy. There is also the article Boolean function, which never defines what a boolean function is. Is there a difference between the concepts of "boolean function" and "boolean-valued function"? What is sorely missing here are examples. There is further an article Logical connective, which treats operators like AND and NOR, the redirect page Boolean operator redirecting to Logical connective, and the redirect pages Boolean operation, Logical operator and Logical operation, which instead redirect to Boolean function. --LambiamTalk 20:03, 26 June 2006 (UTC)
thread_title: Request from non-mathematician

message: Are people interested in having the \mathscr command available? (Provided by \usepackage{mathrsfs}.) Here's what it looks like:
The top one is \mathscr, the bottom is \mathcal (which is what we have now). I've noticed that \mathscr (or something similar) is quite popular in certain fields. I've noticed it especially in functional analysis.
There wouldn't be any difference in MathML because MathML only defines a single "mathvariant=script".
Opinions welcome. Dmharvey 19:25, 28 June 2006 (UTC)
replies: text: It's also popular in algebraic geometry, for denoting sheaves and sheaf-y versions of various things like functors.  I've once or twice wished I could use it.  It's not essential, but I guess I would say that I'm interested in having it. Ryan Reich 21:11, 28 June 2006 (UTC)
replies: text: Do we get one or the other, or can we have both? Personally, I find \mathcal very useful at times, and wouldn't want to lose it. If we can have \mathscr for those that want it, without losing \mathcal, then that would be great. Madmath789 21:21, 28 June 2006 (UTC)
replies: text:  You get to have both. Unless you're viewing with MathML, in which case they look the same. This would only become a problem in articles that use the same letter in the two fonts to mean different things. It would be possible to disable MathML for \mathscr if that's what people wanted, in which case it would fall back on PNGs. Dmharvey 21:50, 28 June 2006 (UTC)
replies: text:  MathML is only part of the obstruction. Unicode itself has no font variation facility to handle this (that I know of). There is a code point for "B" (U+0042) and "b" (U+0062), and for "Б" (U+0411) and "б" (U+0431), and for "ב" (U+05d1), and for "𝔅 (U1d505) and "𝔟" (U1d51f), and for "𝔹 (U1d539) and "𝕓" (U1d553), and for "ℬ" (U+212c) and "𝒷" (U1d4b7). The idea seems that be that these variations of "B" are in separate alphabets (Latin, Cyrillic, Hebrew, Fraktur, double-struck, and script), not separate fonts. (The difference between uppercase and lowercase is an anomaly, retained for historical reasons even though it's somewhat inconsistent.) So an argument would have to be made to the Unicode committee that there is an essential semantic difference between the calligraphic alphabet and the script alphabet. I'm guessing it would be a hard sell; we all know mathematicians have a boundless appetite for new alphabets and new characters. (We need this alphabet for the space, and that one for the structure over the space, and the other one for the mapping of the structure over the space, and so on.) I think we already have enough distinctions to tough it out if we must! In fact, any author who wants to make a semantic or type distinction between script and calligraphy is already unkind to readers. For those who are still not persuaded, MathML accepts CSS styling, so it's possible to use a Latin code point and ask for a different font-family. --KSmrqT 01:18, 29 June 2006 (UTC)
replies: text:  All very true. In fact, there are a few more: for example there's also 𝖡 (U1d5a1) which is "MATHEMATICAL SANS-SERIF CAPITAL B" (). Interestingly, the reference glyphs for script letters given on the mathml site () appear to be the same as the \mathscr above, even though the fonts that I got from the Mozilla site render more like \mathcal. I wonder what the STIX ones will look like. Dmharvey 01:42, 29 June 2006 (UTC)
thread_title:  \mathscr anyone? 

message: You know how we all put something like "\,\!" at the end of  blocks to force the output as PNG? Well I was just doing some database work and happened to be trying things out on the hebrew wikipedia, and discovered that they all put "\ " at the beginning of the equation! (e.g. ) Or is it the end of the equation? I don't even know... the  comes before the <math>... Dmharvey 22:02, 28 June 2006 (UTC)
replies: text: The LaTeX equation itself runs from left to right. In this equation the "\ " is at the beginning. If we think of the eqn as an atom in a right-to-left context, then to the reader the blank space appears to appear to the left of and therefore after the atom (instead of being part of the atom). --LambiamTalk 22:50, 28 June 2006 (UTC)
thread_title:  he he he 

message: More database work.... last time I checked around the beginning of March, the 13 largest wikipedias had 208,000 distinct equations altogether. Now (as of about mid-June) there are about 289,000. That works out at about a 10% growth rate per month. Pretty amazing. Dmharvey 02:06, 29 June 2006 (UTC)
replies: text: You should write a paper about it.  When it gets published, I can write a Wikipedia article about the paper. Ryan Reich 02:53, 29 June 2006 (UTC)
replies: text: And make sure in the Wikipedia article that you use more formulas :-) —Mets501 (talk) 03:15, 29 June 2006 (UTC)
thread_title:  interesting statistics 

message: Is there a way to have a redirect focus the point on a specific section of the article?  Specifically, I have in mind the redirect from Koszul connection to covariant derivative, which reads
: # REDIRECT covariant derivative#Koszul connection
If you follow the link explicitly, by clicking the above link, then the point focuses on the relevant section.  But if you follow the link Koszul connection, then you are taken to covariant derivative without the change in focus.  Any thoughts or advice?  Silly rabbit 17:32, 29 June 2006 (UTC)
replies: text: See Help:Link#Redirects_with_section_links.  I recall reading a different document that explicitly said that they had no intention of ever allowing section links within redirects, but I don't know where that went (the "Help" is not always very much help here; they make it very hard to find the detailed manual and I always forget how). Ryan Reich 18:05, 29 June 2006 (UTC)

text: Hehehe... I just found some related results, and was about to come here and answer my own question: Meta:Help:Redirect#A redirect to an anchor and bugzilla:218.  It's kind of annoying that this seems to be impossible.  Any stylistic pointers on how to handle a merger of this sort? Silly rabbit 18:13, 29 June 2006 (UTC)
replies: text:  Redirect to the top of the page.  If the article is well-written then the appropriate section header will be in the TOC and clearly visible (i.e. the preamble won't take up much space).  If not, well-rewrite it.  In any case, if you have a page that used to link to Koszul connection, you could just put a pipe in that link and avoid the redirect entirely. Ryan Reich 18:45, 29 June 2006 (UTC)
thread_title:  Redirect question 

message: This article is extremely POV, particularly considering the open criticism of Geostatistics within the main page. I was hoping that someone with more experience could build some equations and expand on the evolution of geostatistics. Considering how widely geostatistics is used for the natural sciences, environmental planning, climate studies, oceanic studies, military analysis, urban planning, and Geographic Information Systems, this topic warrants some attention from math experts. SCmurky 03:56, 30 June 2006 (UTC)
replies: text: JanWMerks is at it again.  He's been editing geostatistics, semivariance, spatial dependence, variogram, sampling variogram, kriging, junk science, consensus science, Tolstoy syndrome, and Bre-X; I may have missed some. He's been admonished in the past for his crusading; see his talk page and his list of "contributions". It might be nice if more people added these pages to their watch lists to undo his edits.  (BTW, SCmurky, why did you delete my previous comment?)  Lunch 17:50, 30 June 2006 (UTC)
replies: text: Maybe it is time to take more serious action Wikipedia:Resolving disputes posibly a request for mediation. --Salix alba (talk) 20:03, 30 June 2006 (UTC)
thread_title:  [[Geostatistics]]