User talk:Wvbailey

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Hello Wvbailey, and welcome to Wikipedia! Thank you for your contributions. I hope you like the place and decide to stay. Here are a few good links for newcomers:

I hope you enjoy editing here and being a Wikipedian! Please sign your name on talk pages using four tildes (~~~~); this will automatically produce your name and the date. If you have any questions, check out Wikipedia:Where to ask a question or ask me on my talk page. Again, welcome!  -- KHM03 15:34, 6 January 2006 (UTC)


Your e-mail[edit]

Hi, I got your e-mail, but you aren't blocked. And I see that you've made edits more recent than your e-mail to me, so I assume whatever the problem was has gone away now. --Angr (tɔk) 06:01, 8 January 2006 (UTC)

Proof of impossibility[edit]

Very nice article on Proof of impossibility!

Meekohi 02:39, 15 January 2006 (UTC)


Saw your comment on Talk:Fractal. I removed your annotation on your Fractals for the Macintosh reference on the fractal page because it is not consistent with the style of the other references on that page, and does not match any of the reference styles recommended in the style guide Wikipedia:Citing sources. If you want to provide a description of this length for a reference, it is better practice to create a page for the book itself and put the description there, then use the book's title as a link from the reference to the book's own page. That way, any other articles which use the same reference can also link to the book's page, rather than repeating the whole description. Gandalf61 12:10, 28 February 2006 (UTC)


Thanks for your intervention and witnessing on the talk:David Hilbert page. I'm taking a time-out and will check back in later. I have tried very hard to engage only productively, but it is quite difficult! John (Jwy) 19:12, 8 March 2006 (UTC)

Licorne's been a challenge to many of us. FWIW - with pretty high certainty we know the guy's name, we know where he lives, and we know where he got his PhD and what its title was .... all this does NOT seem to help anything in dealing with him, unfortunately. The anonymity of the net can be blamed for a lot, but not for Licorne. Thanks for trying to think straight! --Alvestrand 20:43, 9 March 2006 (UTC)


Hi Bill! I agree with your sentiment about Licorne. I don't know if your message is in the right place and of the right form, though. Essentially nobody on Wikipedia will accept his behaviour. I suspect that without the running RfAr, someone would already have banned him outright. Now people are just waiting for the official pronouncement. So we will be rid of him fairly soon. As for the place: Wikipedia:Requests_for_arbitration/Licorne/Evidence is for evidence only. May I suggest to move your remark to Wikipedia_talk:Requests_for_arbitration/Licorne/Evidence?

Have a nice day! --Stephan Schulz 18:54, 14 March 2006 (UTC)

quoting from taocp[edit]

Hi, I reverted your edits to algorithm, as I doubt quoting that amount is allowed. By the way, in the third edition he gives al-Khwarizmi's name as "Abū ʿAbd Allāh Muḥammad ibn Mūsā al-Khwārizmī". Cheers, —Ruud 18:46, 29 May 2006 (UTC)

My editions states: "All rights reserved. No part of this publication may be reproduced...". I know you can quote pretty much anything of any length in an academic paper (you have to if you don't want to be accused of plagiarism), but on Wikipedia you also have to think about copyright. I'm afraid you will have to do a bit of creative writing of your own (and attribute Knuth as well). —Ruud 18:56, 29 May 2006 (UTC)

The 1961 Report of the Register of Copyrights on the General Revision of the U.S. Copyright Law cites examples of activities that courts have regarded as fair use: “quotation of excerpts in a review or criticism for purposes of illustration or comment; quotation of short passages in a scholarly or technical work, for illustration or clarification of the author's observations; use in a parody of some of the content of the work parodied; summary of an address or article, with brief quotations, in a news report; reproduction by a library of a portion of a work to replace part of a damaged copy; reproduction by a teacher or student of a small part of a work to illustrate a lesson; reproduction of a work in legislative or judicial proceedings or reports; incidental and fortuitous reproduction, in a newsreel or broadcast, of a work located in the scene of an event being reported.” [1]

None of the situations above describe your use of the quotation as it was not used in a critical context, but as part of the article's message. As Wikipedia can be considered operating in the same marketplace as Knuth does with his "The Art of Computer Programming" this cannot be considered fair use. —Ruud 19:22, 30 May 2006 (UTC)

keep it civil, please[edit]

I have no idea what I have done wrong to you, but stop the immature name calling please. —Ruud 17:36, 30 May 2006 (UTC)

Civility, please[edit]

Please see Wikipedia's no personal attacks policy. Comment on content, not on the contributor; personal attacks damage the community and deter users. Note that continued personal attacks may lead to blocks for disruption. Please stay cool and keep this in mind while editing. Thank you. -R. S. Shaw 19:28, 30 May 2006 (UTC)

I don't know you or Mr Ruud. Perhaps he did make some poor edits. The editing needs to be straightened out. Regardless of that, we need to proceed in a civil manner, without growling or name calling (despite the theraputic effect that might have for our speens). -R. S. Shaw 20:13, 30 May 2006 (UTC)

Algorithm references[edit]

I appreciate all of the references that you are adding to Algorithm. However, I was wondering if you might consider making them cite.php-style inline references (See Wikipedia:Footnotes). That way we'll know which specific reference is relevant to a particular piece of text in the article. Also, you might like to use the {{cite book}} and {{cite journal}} templates to help achieve a standard format (although I'm happy to keep going through and converting the references to the template forms as you add them, if you prefer). Thanks. --Allan McInnes (talk) 18:04, 31 May 2006 (UTC)

Helpful article[edit]

I came across this article: THE PRINCIPLE OF EXCLUDED MIDDLE THEN AND NOW: ARISTOTLE AND PRINCIPIA MATHEMATICA. I had no time to read it yet, but from glancing through it, I think this is just what is needed. It is an essay, not in encyclopedic form, so the information given there needs to be rephrased, but my impression is that the author has a good grasp of the issues and presents them in an insightful way. It also has adequate references. --LambiamTalk 11:56, 3 June 2006 (UTC)

Honestly, I don't see that Andrews' essay supports the assertion that Gödel was strongly influenced by the debate. I only see suggestions the other way around: "'Intuitionism' ... found new impetus in the results of Godel." and "the [intuitionist] position was strengthened by Godel's results". And as far as reductio ad absurdum is concerned, I only pointed out that the intuitionist rejection of LoEM does not impact on the validity of negative results reached that way. And I only did that because you wrote: "If the law were to be abandoned, e.g. Turing's proof and Godel's proof (1931) would be in serious jeapordy." And after I contradicted that, you wrote: "I don't agree with you about the Turing proofs (plural). The Godel proof(s) worry me too". The point I made was that, being negative results, they were not in danger.

As to your "Wikipedia experience", I am sorry it has been so unsatisfactory for you. The best advice I can give you is to stick to topics for which you are confident about your understanding of what is written about them, and to build articles up piecemeal, making sure that intermediate versions are presentable too. It is better to omit something, than to let the scaffolding show by leaving in sentences in telegram style and tags like "work in progress". That discourages other editors from working on the article. Best wishes. --LambiamTalk 20:29, 3 June 2006 (UTC)

The reason I'm not writing is simple: I don't have access to a library, so I cannot "source" what I write. So instead I try to shape up things, correct obvious errors, increase clarity and such. If original research was allowed, it would be a different story, except that Wikipedia would then be so full of cr*p that I probably wouldn't want to contribute. For the record, I did not propose that editors write only "about what they truly know", but, instead, only about that for which they truly understand what already has been written on the topic. In other words, if editors read up on a topic and are not quite confident they get it, they should simply refrain from reporting on it.

The Wiki model is not perfect, and I see several ways of improving it, but I am actually surprised it is working as well as it is. Personally I find Wikipedia an increasingly useful source of information. --LambiamTalk 23:13, 3 June 2006 (UTC)

Martin Davis[edit]

You might try asking him directly, he's a nice guy. Here is his NYU web page, with e-mail contact, telephone, everything: --LambiamTalk 00:41, 4 June 2006 (UTC)

Quoting from an e-mail is problematic; it is "unverifiable" under Wikipedia's definition. But if you can know of a published source (book or article) in which Davis first used the term, you have my blessing (if it counts for something) to cite that while using a phrase like: "The term Halting Problem was coined by Martin Davis <citation>." --LambiamTalk 13:33, 4 June 2006 (UTC)

On the halting problem[edit]

This is a response to a question you posed on Halting problem. You asked:

Early this year I first came to Wikipedia with this question: 
why does Turing's "circle proof" seem so different than the "halting proof"? 

I looked through Turing's 1936 paper in which he defines circular and circle free machines. Turing's goal in that paper is to consider machines that enumerate the decimal expansion of a real number. Because these machines enumerate the expansion in order, either they produce a complete infinite expansion or they produce a finite initial segment of one. Thus the question is whether the expansion produced by machine e is infinite or not. The set of those e that produce an infinite expansion is of Turing degree 0’’. The Halting problem is Turing equivalent to the set of pairs (e,n) such that machine e halts on input n. This problem is of degree 0’.

If you view an enumeration of a decimal expansion, as in Turing's paper, in the modern way as a partial computable function f that takes each n to the nth digit of the expansion then the question of whether any particular digit is assigned a value (that is, whether f(n) converges for a particular n) will in general be equivalent to the halting problem. The question Turing asks is whether every digit is assigned a value. This requires quantifying over infinitely many instances of the halting problem, which intuitively is why it is of higher degree.

After looking through Turing's paper, I believe Turing knew or should have known that the Halting problem is undecidable. He was not considering partial computable functions, which is I believe is the reason that he did not bother to mention it.

in fact is it O-prime (as in "Oracle-") or zero-prime? -- Davis used O not zero

The notations 0’ and 0’’ come from the poset structure of the Turing degrees. The least degree is named 0 (zero) as the least element of a poset often is. For each Turing degree a there is another degree a’ pronounced a prime. Thus 0’ is (0)’ and 0’’ is (0’)’. If Davis used an O instead of a 0 it might be because the two look the same on many people's screens and typewriters; this is only a guess. The pronunciation zero prime is universal. CMummert 14:54, 22 June 2006 (UTC)

Unfortunately, I do not have time right now to spend on the Turing's proof article. Perhaps once I finish the other things I have in mind, I will be able to return to it. CMummert 03:00, 28 June 2006 (UTC)

You asked for a recommendation for a book on computability theory. My memory is that the book by Cutland would be good for self study (I don't have a copy at hand). It is aimed to be a first course for undergrads. If you need more advanced books, the books by Rogers and Soare are thorough introductions at the graduate level. I would start with Cutland, though. CMummert 23:05, 28 June 2006 (UTC)


Thank you for finding this source. Robert A.West (Talk) 02:27, 13 August 2006 (UTC)

Hello on Turing Machine[edit]

There are a new sugestion.

Algorithm definition: example[edit]

Hi Wvbailey. I came across this article, and am inclined to nominate it for deletion. Apart from the fact that it doesn't seem finished (or at least it does not to me show anything about the definition of algorithm, as it claims), it is not normal to have supplements to articles in that form. If there is not room for explaining the problems of a definition in the algorithm article, perhaps something like Definitions of algorithm would be a better idea, explaining different views, with examples. In any case, I would suggest moving this page to your userspace until it is more complete. JPD (talk) 15:33, 30 August 2006 (UTC)

(PS: While the Manual of Style does allow the use of the first person "we" in things like mathematical derivations, we are encouraged to avoid it in general, writing in a more encyclopedic tone. JPD (talk) 15:36, 30 August 2006 (UTC))
Hi Bill. As you say, the article is obviously not complete. Since to me it seems not even complete enough to be clear what it is about and allow others to contribute to it, I don't think it should be the main article space. I can understand that you want to work on it in Wiki formatting before it is ready, and that is why I suggest you could work on it at User:Wvbailey/Algorithm definition: example or something like that, until it is ready to be in the main space. This is a good way to work on things before they are ready, there you won't have any problems with "�impatient" users. You can move it by clicking on the "move" tag at the top of the page. Apart from that, as I mentioned I think a more general article on definitions would be more helpful and more inline with the Wikipedia style than an article on an example. I hope this helps. JPD (talk) 09:31, 31 August 2006 (UTC)

Questions in Talk:Recursion theory[edit]

You asked several questions there, which I don't want to address on that talk page because they are not relevant to that article. Hare are some brief answers:

So I ask: in layman's terms, what is the difference between all these kinds of recursion?
  • Primitive recursion This is a specific model of computation, weaker that Turing computability, described at primitive recursive function
  • Partial recursion and Full general recursion. These are the same. They provide a formal way of dealing with finitary functions on the natural numbers defined by sysytems of recursive equations. They are equivalent to Turing computable functions (that is, once the definitions are laid out properly). For example, multiplication is the function M defined by
A(n,0) = n,
A(n,m+1) = A(n,m) +1,
M(n,0) = n,
M(n,m+1) = n+A(n,m).
This is also primitive recursive. The Ackermann function is defined by recursion equations that are not primitive recursive but are general recursive.
And what is 'the minimization operator' that Elgot-Robinson and Minsky mention? Is this necessary for "full general recursion"? It is the Mu operator. It is required, beyond the operations of primitive recursive functions, to compute all the partial recursive functions.
CMummert 00:21, 18 September 2006 (UTC)

Halting problem[edit]

I read through the article Halting problem this morning. It is turning into a good article. I noticed that you have a long list of historical references that you have researched. I wanted to point out the Wikipedia policy on original resarch WP:OR. It discourages historical research like you have done (the policy is not math specific, but is also intended for areas where secondary sources are more likely to give comprehensive viewpoints than primary sources). In the math articles, there is some balance between the original research policy and the need to allow writers to use their personal knowledge when writing articles (so, for example, the article recursion theory that I wrote might also qualify as original research under a pedantic reading of the rules).

In particular, WP:OR says (emphasis added):

Articles may not contain any previously unpublished arguments, concepts, data, ideas, statements, or theories. Moreover, articles may not contain any new analysis or synthesis of published arguments, concepts, data, ideas, or statements that serves to advance a position.

In the Halting problem article, you spend a long time justifying that M. Davis was the first to use the phrase halting problem. I don't propose cutting that material out, but to fit with WP it should be edited so that it doesn't appear to be an argument in favor of a new position. A shorter reference that states that the phrase appears in Davis and is not known to appear in previous works would be fine IMO. On the other hand, if you could find a statement in print (unfortunately, email and WP talk pages aren't suitable as references) that says the phrase originated with Davis, this would be a great reference.

By the way, thanks for your work on Halting problem and Turing machine. These are difficult articles to write because they are of broad interest but more technically challenging than most elementary mathematics.

CMummert 12:44, 27 September 2006 (UTC)

It might not have been your intention, but you recently removed content from Counter machine:Reference model. Please be careful not to remove content from Wikipedia without a valid reason, which you should specify in the edit summary or on the article's talk page. Thank you. A link to the edit I have reverted can be found here: link. If you believe this edit should not have been reverted, please contact me. TheRanger 21:02, 25 October 2006 (UTC)

Your edit to Register machine models[edit]

Your recent edit to Register machine models (diff) was reverted by an automated bot that attempts to recognize and repair vandalism to Wikipedia articles. If the bot reverted a legitimate edit, please accept my humble creator's apologies – if you bring it to the attention of the bot's owner, we may be able to improve its behavior. Click here for frequently asked questions about the bot and this warning. // AntiVandalBot 22:19, 9 December 2006 (UTC)

Article in need of cleanup - please assist if you can[edit]

articles citing other articles[edit]

The best description in policy is at WP:CITE, where it says in bold

Note: Wikipedia articles may not be cited as sources.

Based on comments I have seen from other editors, it seems this is interpreted to mean that references should be duplicated for all articles where they are used. It makes sense to point to another article's references if you are thinking in terms of subarticles, but the way things are set up no article is a subarticle of another. CMummert 04:02, 6 January 2007 (UTC)


I cleaned up Entscheidungsproblem some. You are probably more familiar with the references than I am. Do you know if Hodges covers the history of the problem as discussed in the article? I put a cite tag between the two sentences that I am interested in. CMummert · talk 14:42, 12 January 2007 (UTC)

Thanks for the reference; I added it to the article and resolved the fact tag.
If you are interested in finding out about more about intuitionistic math, I recommend that you read about the BHK interpretation and read the introduction of "Varieties of Constructive Mathematics" by Bishop and Bridges. If you want something more advanced, there are some books by Troelstra about constructivism in the references for BHK interpretation. In contemporary parlance, "constructivism" includes all sorts of mathematics done with intuitionistic logic, but without the philosophical baggage. CMummert · talk 17:10, 12 January 2007 (UTC)

Godel 1931[edit]

Thanks for the offer of a PDF of the translation of Godel 1931. I have the book in front of me, so I can't take you up on it. I can make a counter offer - the PDF of the original 1931 paper in German, from SpringerLink online. If you can use it, send me your email address (with the "email this user" link on my user page).

Also, any edits you would like to make to On Formally Undecidable Propositions of Principia Mathematica and Related Systems would be very welcome. CMummert · talk 02:01, 25 January 2007 (UTC)

Active voice on Algorithm[edit]

Hi, Your active voice looks nice. As long as we do not make first person or second person as subject, I am happy with it. mlpkr 09:56, 31 January 2007 (UTC)


The point of a shortcut box is not to list every single incoming link (that's what we have Special:Whatlinkshere for). The point is to list one or two common abbreviations as mnemonics. For instance, if WP:ABC is renamed to WP:XYZ, it doesn't make sense to keep the old shortcut in the box, even if we won't delete it. >Radiant< 16:51, 14 February 2007 (UTC)

Taxonomy of abstract machines[edit]

You added a taxonomy of abstract machines. Where did you get this from? Gdr 13:40, 8 July 2007 (UTC)

Bad JPEGs[edit]

I put {{BadJPEG}} on Image:State diagram 3 state busy beaver 4 .JPG, and I was about to put it on some other images you uploaded, but it looks like it would apply to the majority of them, so I guess it's better to just tell you. Please don't upload drawings as JPEGs. According to Autodesk's web site, AutoSketch supports Windows Metafile. Those aren't fit to upload to Wikipedia, but if you send them to me I can probably convert them into SVG and that would be the absolute best solution. Failing that, please export them as PNG rather than JPEG. If you have some old version that doesn't support PNG, GIF will do as well. Really the only bad one is JPEG, which should almost never be used for anything other than photographs. —Keenan Pepper 08:43, 10 July 2007 (UTC)

I'm way far away from the real world (i.e. I'm in Wyoming USA)
LOL, my roommate is from Wyoming and he agrees.
there were no contra-indications from wikipedia until now
That's because it's impossible for a computer to judge whether JPEG is appropriate for a given image. There's nothing wrong with JPEG, but it's designed for photos with their smooth color gradients. Using it on computer drawings with sharp, straight lines is a mistake. It's just a pet peeve of mine; don't worry about it too much. —Keenan Pepper 02:53, 11 July 2007 (UTC)

License tagging for Image:Pithouse at Step House Mesa Verde 2.jpg[edit]

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Architecture in the Southwest[edit]

Hi! Thanks for your note. I noticed your efforts on Kiva and appreciate your interest in the Dugout/pithouse article. Neither of them get much attention. If you are interested in continuing to edit on Southwest architecture, take a look at Pre-historic Southwestern Cultural Divisions (probably to be renamed in the future, see talk page). This article has been a long term goal of mine and is just getting out of the "wish" stage. I intend to add larger sections on agriculture/irrigation and warfare. Settlement patterns/architecture would fit right in. Look forward to working with you. (P.S. - I also know how to use a slide rule. Dating ourselves, aren't we?) WBardwin 01:55, 26 July 2007 (UTC)

Remarks on Finsler's paper "Formal proofs and consistency"[edit]

I looked through the comments about this paper that you pointed out to me, by Holmes and van Heijenoort. van Heijenoort's remarks on p. 440 seems to indicate that v. H. doesn't feel Finsler has succeed in a successful analysis of an undecidable statement, because Finsler has failed to properly distinguish between formal systems and metasystems. v. H. says that the distinction Finsler makes between "formal" and "conceptual" can "hardly be sustained." That is a quite sharp criticism for an editorial comment such as this. My impression of Finsler's paper is that it anticipates Godel's work in spirit only. There is nothing in Finsler's paper that suggests how to obtain Godel's result, as Finsler doesn't anticipate the formalization of syntax that Godel developed. — Carl (CBM · talk) 19:18, 29 August 2007 (UTC)

Little context in Church-Turing thesis: History[edit]

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Church-Turing thesis: History[edit]

I think this is a super piece of work and if you don't mind, I'd like to add some internal and external links.

If it is something you are working on, I'll wait.

Alan A. Jorgensen, Ph.D.

Softtest123 22:24, 2 September 2007 (UTC)

I did some work on your References. If you don't like it, back it out, let me know what you would like, and I'll start over. I could not find your citations, "Hawking" and "U." probably in there somewhere, if so, let me know, I'll dig them out and make listed references out of them.

Alan: Softtest123 21:13, 3 September 2007 (UTC)

"U" is The Undecidable and you are correct, Hawking is missing. I'll put him in. wvbaileyWvbailey 22:18, 3 September 2007 (UTC)
Shouldn't that be some particular author to be consistent? I don't understand the reference to The Undecidable. Softtest123 22:56, 3 September 2007 (UTC)
Okay, I have the picture on Davis. Now, in order to create references consistent with the others, should/could I change there "U." citations to "Davis"? You have some explanation in the reference, perhaps including some of what you sent me into the Davis reference would help when it is unclear whether the citation is for Davis or one of the others. I hope I didn't mess this up by changing your list of included papers to "in (Davis..."? Softtest123 05:37, 4 September 2007 (UTC)

I'm having some problem following this discussion between here and my talk page. Could we agree on a single place for the discussion? I have a watch on your talk page so that would work, or we could use mine.

Which do you prefer?

Softtest123 14:02, 4 September 2007 (UTC)

Let's stay here. I've copied over from your page to mine what I just wrote there (wvbaileyWvbailey 14:06, 4 September 2007 (UTC)):
Hi, I've had a hard time with "The Undecidable" citations too. One way I've done them is something like this (which seems to me the best way, but the most laborious):
(Gödel in Davis 1965:24)
And perhaps when Davis is commenting, something like this:
"Dr. Gödel has stated in a letter that that he was, at the time of these lectures, not at all convinced that his concept of recursion comprised all possible recursions . . .."(Davis in Davis 1965:40)
I believe I've also done it this way -- put a note at the top of the page that "U" in the citations indicates reference to The Undecidable, so you could then do either of these (this method is maybe better when you have a bunch of co-authors or long names like (Whitehead and Russell (1910) in van Heijenoort 1967:216):
(Gödel in U:24), or more vaguely (U:24)
I suppose any of these are okay so long as the reader can figure out where to look up the quote. wvbaileyWvbailey 13:51, 4 September 2007 (UTC)

Okay with me.

However, I have a problem. I have been editing for the last two hours and now I can't update the page because of your minor edits. How can we resolve this?

Softtest123 16:17, 4 September 2007 (UTC)

Strange. Did you encounter an "edit conflict?" Sometimes the stuff does get lost; this definitely is an annoyance and happens frequently. What I will do is stay off the page and let you do what you want to do, and when you're done, let me know so we don't get into these edit conflicts. Or if you are editing the whole thing "off line" (i.e. in your word processor) and you "paste over", I won't have edited in the meantime. Will that work okay for you? wvbaileyWvbailey 17:48, 4 September 2007 (UTC)
I was editing the whole thing because I was walking through the entry inserting local references. Probably not a smart thing to do. I still have the edits so what I will be doing is going through each section and merge in my changes. No big deal and there really shouldn't be any edit conflicts, if there is, I'll just remerge. As long as you edit a single section at at time (which is what I will now be doing) the chances of a conflict are pretty remote.
I'll check to see where you changed things and merge that by hand. Anything you didn't touch, I'll simply replace.
I'm over my miff about not being successful after spending so much time being stupid.
Softtest123 15:39, 5 September 2007 (UTC)

I think a common way of handling the citation issue is to use footnotes (see my piece at Abax). Eventually, with your approval, I'll change Church-Turing thesis: History citations to that style. That way all you would have to do is edit a specific footnote to include some of these comments on the difficulty of citing sources. Footnotes will also clean up the readability of the article.

I personally don't have a problem with this (I agree it does aid the readibilty), but I'm confused about what is considered "best practice" in wikipedia. I keep seeing problems with "delisting" due to lack of "in-line" citations. But perhaps "inline citations" includes footnotes. I'd say, give it a whirl and lets see what it looks like. wvbaileyWvbailey 23:49, 5 September 2007 (UTC)

But first I want to put in local and external references to make the article stronger (though strong now it is).

Softtest123 15:49, 5 September 2007 (UTC)

I think that is as far as I got yesterday inserting local references. In any case I am finished for now. Softtest123 16:39, 5 September 2007 (UTC)

I think we are missing the reference for "De Pisapia 2000". Softtest123 22:09, 5 September 2007 (UTC)

Hmm. I will have to figure out. This may be a quote within a quote. I don't recognize this as a paper that I have. wvbaileyWvbailey 23:49, 5 September 2007 (UTC)

Are the spelling errors in the quotes in 'Sieg 2002 discusses "axiomatic definitions"' in the original or do they need to be corrected? Softtest123 22:15, 5 September 2007 (UTC)

Hmm. I will check. wvbaileyWvbailey 23:49, 5 September 2007 (UTC)

Also, I have an issue with the number and length of actual quotes in your piece. You may get nabbed for that. I think that I can edit some of the quotations, either by reducing quotations to their essence or paraphrasing. Would that be all right with you?

Yes. In general I am having a "readability" issue with this whole string of little snatches of factoids. My original intent was to do just that, put down the factoids as accurately as humanly possible. But now that the factoids are part of (actually are) an article, I agree that some of the quotes may be too much. Go ahead and edit, but if you can, hide rather than delete the missing text i.e. use the "" (I can't write it because it vanishes! Jeezum...) around the stuff to be deleated. wvbaileyWvbailey 23:49, 5 September 2007 (UTC)

Softtest123 22:20, 5 September 2007 (UTC)

<nowiki> and </wiki> tags can be used to make wiki editing marks appear. (I love recursion and self reference.)

For instance: "<!--" and "-->"

And that is a good idea. I'll preserve your original work as comments, though I am not sure that the copyright police won't catch that as well, if the long quotations appear to violate "fair use" policy.

Softtest123 05:15, 6 September 2007 (UTC)

Here is the wiki-policy but I have no idea what "brief" and "extensive" mean. I would guess that the entire article that I copied from the Valley News Talk:George Stibitz would be "excessive". I worry more about the scholarship than offending some self-appointed "wiki-police". If the author/owner complains, that's a different story.

Wiki's policy on "Acceptable use of text"

"Brief quotations of copyrighted text may be used to illustrate a point, establish context, or attribute a point of view or idea. Copyrighted text must be attributed and used verbatim. Any alterations must be clearly marked, i.e. [brackets] for added text, an elipses (...) for removed text, and emphasis noted after the quotation as "(emphasis added") or "(emphasis in the original)". Extensive quotation of copyrighted text is prohibited.

wvbaileyWvbailey 14:29, 6 September 2007 (UTC)

So noted. Nevertheless, to avoid what I feel may be unnecessary effort defending "fair use", I am commenting out quotations or portions of quotations (with ellipses) when I think the quotation does not directly support or refute the thesis of the section which contains it. I may comment out portions to make a quotation more readable if I can do so without changing the original author's intent. I'd rather debate with you than with someone I don't know who doesn't know what we are talking about.
In fact, the "wiki-police" are not likely to debate the issue but rather butcher something to avoid complaints from authors. Authors are more likely to complain with civil suits that could damage the entire Wikipedia effort. I'd rather perform some surgery to avoid that, particularly if that makes a section more readable and to the points you are making.

I am having a problem verifying the citations in Ackerman 27-28. In particular, I have no specific source for (Sudan 1927), (Ackermann 1928) , nor (Kleene, p. 271). (Kleene 1952:271). I have two references for Kleene so I'll need to add dates to the citations. I assume all of your citations for Kleene are (Kleene 1935)? In fact, all citations will need to have dates since anyone could add an additional reference for an author we already have. I'll do that if no one else does.

(Ackermann 1928 is referenced by Kleene 1952:271 (actually all through his § 55. General Recursive functions pp.270-276) and in his bibliography on p. 518. Ditto for Péter in the text body and in his bibliography on p. 531. She must have been quite a mathematician; her name pops up every now and then.)

I see that you are making good progress on the history section of the main article. Keep up the good work.

Thanks, you too. Yes we're both making progress. Prune away.

Softtest123 13:46, 9 September 2007 (UTC)

Another editor claimed that Gabriel Sudan produced the first example of a non-primitive-recursive function so I just threw this in; I'll look at the Sudan article to see if there are any references; I have no references myself. The references I used are from Kleene 1952:270ff. His § 55 is a fascinating discussion of the failure of primitive recursion as discovered by Ackermann 1928 and Péter (1934, 1935); Péter's example is very easy and uses diagonalization to produce a number not in the enumeration of functions. So with regards to Kleene there are three possible references
Kleene 1936 in Davis 1965:237ff (I'm not sure this one is used, but there's good stuff in it)
Kleene 1943 in Davis 1965:255ff (Here's where "THESIS I." appears on p. 274)
Kleene 1952 (This is Kleene's text book where he proposes both theses and equates them with his proof XX, where the Ackermann-Péter business is discussed, etc).
WhatI recommend is to delete the Sudan reference by hiding it. How about putting a reference to Sudan in a footnote?
I just read the Gabriel Sudan article. It is well referenced. Without pursuing each reference, and doing a library research to verify, especially his supposed 1927, I don't know what to make of this. Why Ackermann and Péter get the glory and not Sudan represents a mystery. These folks all knew each other and published widely. One would have to read all the sources, then get Ackermann's and Péter's papers from the journals and see their references. Good luck since its probably in German and Czech or whatever.wvbaileyWvbailey 16:32, 9 September 2007 (UTC)
When you're done, I will go through and double-check all the references for pages and dates and etc etc. I find that I make lots of mistakes.
As for the article page, I think I'm (mostly) done with the upper half of it. An exception might be more about "effective calculability", perhaps an example in the manner of the Stanford article (see immediately below). Also the little Entscheidungsproblem entry seems sparse. I have some questions about the relationship between effective calculability and total functions.
But the bottom half needs, at least, some references. Last night I read the reference at the Stanford Encyclopedia of Philosphy; it has a very long and decent discussion of the philosphers of minds' blunders re misinterpreting the C-T thesis. A solid reference there is probably good enough because it is too detailed with examples and represents a lot of knowledge and research by the author.
Can you think of any additions for the article page? After a while it'll make sense to just stand back from it and let things settle out. wvbaileyWvbailey 16:13, 9 September 2007 (UTC)
I'm still buried in details and haven't looked at the big picture. One of the reason's for making the article more readable is so that I can SEE the big picture.
What I was looking for was the citation for the Sudan reference. You seem to have a copy of the Sudan article cited. What is it? Where could I find it? I am putting all primary article citations into footnotes (there are now 70 and counting), again to make the article more readable. Unlike you, I haven't gotten halfway through what I am working on. Making them footnotes, however, certainly emphasizes the work I have yet to do.
Since (Kleene 1952) is a book, I can probably find that reference. I'll see if I can access (Kleene 52) to find (Ackermann 28) but my life would be easier if you just tell me what Kleene cites of Sudan and Ackermann. I'll keep asking you for things I can't find. (I live in a remote area. It takes me over a month to get a book or article on interlibrary loan and I've had to minimize my personal library. I have only 2 books on the theory of formal languages. The information I am using I am gleaning from the Internet. Google Books is amazing. Did you get my email via Wikipedia? I'd rather put this type of personal information in a personal email. In truth, I think we've met.)
Softtest123 14:59, 10 September 2007 (UTC)

Hi, the only information I have on Sudan is what I wrote above a few paragraphs (you might have missed those para) -- i.e. it comes from wikipedia and I have no other references, so I'd stick Sudan in a footnote. Ackermann 1928 is the following (from the references in Kleene 1952:518):

Ackermann, Wilhelm, 1928. Zum Hilbertschen Aufbau der reellen Zahlen. Mathematische Annalen, vol. 99, pp. 118-133

I wouldn't worry too much about this as a primary reference unless you can read German (I can't read German).

I'm terrible about looking at emails. Yes, go ahead and email me; I'll try to improve my behaviors. You must live in Wyoming. Now that's freakin' remote. wvbaileyWvbailey 15:41, 10 September 2007 (UTC)

Actually Arizona. I'll give your email another try.

Kleene 1952[edit]

Okay. I'm looking at referencing (Kleene 1952). Apparently you are actually looking at a later edition (Kleene 1971) (there are 16 editions). I am concerned that editions have different ISBNs and page numbers. How do you want to handle this? I can see that you would like to note that the comments date from 1952 but they are found in (Kleene 1991)? I suggest changing the reference to

  • Kleene, S. C., 1952, 1971, 1991 ( originally published 1952, ?? edition 6th reprint 1971 with bibliographic updates and two notes added, 10th impression 1991) Introduction to Metamathematics, 550 pages, North-Holland Publishing Company (Wolters-Noordhoff Publishing) ISBN 0720421039

(see That ISBN may be for the 1971 edition.

I'm having some trouble sorting out the publication history of this work.

Softtest123 16:07, 10 September 2007 (UTC)

The cc I have is 1991, 10th reprint. 16 editions? Do you know when was the last impression? I thought that this was out of print; I had to get my cc from a used-book seller. On page VI of my cc it says in a "Note to the Sixth Reprint (1971)" that "In successive reprints various errors have been corrected" but by the list I doubt the page numbers changed. In the 6th reprint, "eleven bibliographical references have been updated" (the references start on page 517) together with two notes on pp. 65 and 316. From this I infer that there were no more "updates" after 1971. My cc indeed ends on p. 550. I have two ISBN numbers for it:

North-Holland ISBN 0 7204 2103 9
American Elsevier ISBN 0 444 10088 1

I added a possible correction to your reference, above. wvbaileyWvbailey 18:52, 10 September 2007 (UTC)

Computer versus computor[edit]

See the comment at Talk:Church-Turing thesis: History. wvbaileyWvbailey 14:42, 6 September 2007 (UTC)

Fixed. Softtest123 13:46, 9 September 2007 (UTC)


I infer that the reference to "Hodges" in Gödel 1930-1931 is to Wilfrid Hodges. The question is, to which work of his do you refer? :Just Turing's biography: Andrew Hodges 1983 (1st edition), Alan Turing:The Engima, Simon and Schuster, New York, ISBN 0-671-49207-1. There may be later editions, but this is the one I used. wvbaileyWvbailey 16:57, 13 September 2007 (UTC):Hmm. Did you mean Wilfried Sieg? Do you mean the quotes in quotes, i.e. Dawson quoting Wilfried Sieg? Or is there a mistyping? wvbaileyWvbailey

I'm looking at reference 16 of Gödel 1930-1931. That is probably Andrew Hodges and Enigma. I don't seem to have that listed. I don't know how I missed the Enigma. I've even read that book! Huh! I didn't realize Douglas Hofstadter coauthored that book. Is that the one reference 16 cites?
I was just taking a stab at who you meant by Hodges. I sure feel dumb.
Softtest123 19:35, 13 September 2007 (UTC)


In the section Church 1936, footnote 32, it looks to me like you are citing a Merriam-Webster dictionary. Could you give me the publication details of the dictionary you have used? If not, I can cite AH and change the wording slightly to match that citation. (See "identify" in

Softtest123 16:06, 14 September 2007 (UTC)

1990, Webster's Ninth New Collegiate Dictionary, Merriam-Webster Inc., Springfield, MA, ISBN 0-87779-509-6 (indexed).

Confusing Sentence[edit]

Could you please clarify:

"Furthermore, to define the if the number is to be considered "computable"

in Turing 1937

Softtest123 01:48, 16 September 2007 (UTC)

Local and External References, Citation Editing[edit]

I am finished, more or less.

As of this writing there are 81 footnotes, 31 references (Not counting embedded ones I might have missed), and 10 external links, most of which are PDF documents of actual papers.

I have adopted a consistent method of citing reprinted papers: Author PDate in (Reprinter RDate:Page)

Where Author is the originator of the material and PDate is when it was originally published. Reprinter is the author of the reprinting book but may be referenced directly when making comments, such as Davis and RDate is the date of publication of the reprint (the actual version you looked at and Page is the page number or numbers where the material cited resides in the reprint.

In some cases I was unable to determine whether the citation was to a specific reprinted paper or to the comments of the reprinter. If a footnote contains only a citation of the reprinter, please check to see whether it is the reprinter's comment or some other original author that needs to be cited.

In some cases I have added references to the original source (but without page numbers unless it is the whole article).

All of my work needs careful scrutiny, of course. I will enjoy watching to see what you do with it, but I think we are getting a pretty good article here. I could not have done what I did without the work you prepared.

Softtest123 16:04, 21 September 2007 (UTC)

Image copyright problem with Image:Function (ordered pairs) 1b.JPG[edit]

Image Copyright problem

Thank you for uploading Image:Function (ordered pairs) 1b.JPG. However, it currently is missing information on its copyright status. Wikipedia takes copyright very seriously. It may be deleted soon, unless we can determine the license and the source of the image. If you know this information, then you can add a copyright tag to the image description page.

If you have any questions, please feel free to ask them at the media copyright questions page. Thanks again for your cooperation. NOTE: once you correct this, please remove the tag from the image's page. STBotI 19:21, 12 September 2007 (UTC)

Pointer machine[edit]

I was looking up information on this topic and so read this article. It has a lot of useful information and it looks like you dug into the literature. Thank you for writing it. —Centrxtalk • 16:48, 2 October 2007 (UTC)

Use of article talk page[edit]

Your extended "thinking out loud" at [[Talk:Function (mathematics)#Alternate example for use in talking about "inverse", etc|Function]] may be fascinating to you, but it is an unwanted imposition on editors like me who watch the page.

Also, I must caution you that we are not going to warp the function article in the direction you seem to be headed. We already have articles for, say, recursion theory and primitive recursive functions. These are fine topics, in their place; not here. It is as if we want directions for how to drive from one city to another, and you want to explain the internal combustion engine. --KSmrqT 11:14, 4 October 2007 (UTC)

I also came here to point out that extremely long posts (like this 10k post) are not a particularly effective way to communicate with other editors. I know that you enjoy source-based research, which is great. If you limit your comments to one or two paragraphs, though, it will make it easier for others to understand the point you are trying to make. It helps me to write short comments because it forces me to find a concise way of saying what I want to say, which improves the clarity of my comments. You can always summarize what the sources say, and be judicious in your quotes.
KSmrq is right that the function article is concerned with the broader mathematical notion of a function, not particularly with notions of effectiveness. Certainly the function article should mention, and link to, an article on computable functions. But computability is a very small field within mathematics. — Carl (CBM · talk) 13:40, 4 October 2007 (UTC)
I'm sorry, in retrospect, if my comment above was worded poorly or caused any offense. Your input on several articles is extremely helpful, so I feel bad when I can't condense a long post to tell what you're trying to say. — Carl (CBM · talk) 18:35, 4 October 2007 (UTC)

form and function[edit]

Thanks for your comment. But keep in mind that the article we're working on is titled function (mathematics). Rick Norwood 12:40, 6 October 2007 (UTC)

The article Function (mathematics) definitions[edit]

This article is somewhat problematic. Would you be willing to move it into your user space (e.g. User:Wvbailey/Function definitions or something like that)? — Carl (CBM · talk) 23:28, 6 October 2007 (UTC)

The issue with articles like Function (mathematics) is that there is a cohesive, well understood concept that is described with slight variations by different authors. In that article it is the concept of function. Focusing on the minute differences between different authors' presentations exaggerates the differences and hides the unified concept that the authors are all describing.

The same phenomenon occurs in the article on ZFC set theory: every author has their own pet axiom system for ZFC, but there is no need for the article to dwell on the differences, because all the authors are describing the same system of set theory in the end. I can give many more examples of this phenomenon.

Because different authors so often choose idiosyncratic definitions, statements of theorems, terminology, etc., our role must be to describe the common ideas, not to emphasize the differences, unless the differences are particularly important or notable. While it is beneficial to anyone to read multiple presentations to get a broader perspective of the topic, it isn't our role at Wikipedia to reproduce all those perspectives. — Carl (CBM · talk) 23:40, 6 October 2007 (UTC)

I happened accidentally to see your note to CBM--let me urge you to continue to develop articles like this as expansions of the basic articles, and if necessary ask help from the community in defending them--an RfC can sometimes work, and there are multiple other directions. You mention also the possibility of taking a historical approach, which is also a good idea, in addition perhaps.; as you surely know, its a good way of teaching & often the earlier unsophisticated expositions are the easier to understand, with the development in time showing the successive modifications. There's an interesting example of this at Second Law of Thermodynamics, though i doubt very much everyone like the current solution. and there are places very much in need of this sort of approach at various topics in probability theory (see Bradford's law and the related pages). There is a real difficulty in trying to get it all into the main article: it confuses the beginners. For an example of multi-layered treatment of a major subject, see Evolution. (and that subject for good measure also has problems with ideology)
but what I came here to ask you is to hope that you expand the article on George Stibitz to include or be supplemented by a discussion of his machines. A biographical approach is great but people here also want to see the technology. DGG (talk) 07:04, 7 October 2007 (UTC)

Thank you for your explanation. In utter frustration I wrote a "letter of resignation" here but then deleted it, and then saw your 2nd post. I don't mind moving it. I do think its name "definitions" is the wrong name ... misleading ... -- KSmrq gave it that name to get me out of his hair. But even given a name change, is there any hope in pursuing a different slant? e.g. historical slant, or a theory-based slant (which is where I was going with it -- I would need some structural help in a list of the major theories -- set theory, number theory?, computation theory, etc. They use different axiom schema so their uses of function seem to be different...). But if no hope, why not just expunge it altogether? I don't want to waste time on something that is hopeless. "Write off the sunk cost," as my daughter the accountant would say. "Fold the hand," as my poker playing brother-in-law would say. Lemme know, thanks, BillWvbailey 00:07, 7 October 2007 (UTC)

I moved your comment here to keep everything together. It would be possible to write about the history of the function concept, but that work should be spent improving the History section of the current article on functions (this would mean the history before 1900 especially, not the history of computability theory in the 20th century). The history section does need improvement, but please don't add large amounts of quoted material, or start another article to hold large amounts of quoted material. Our articles need to distill and summarize other sources to bring out the main points.
I don't think it would work to write about functions in various areas/fields of math because there really is no difference between functions in different areas of math. Although different kinds of functions are studied in different areas, the concept of function itself doesn't change from one field to another - if I were to poll ten people in my department what a function is, they would all agree. They occasionally use different terms for the concept, but the concept itself would be completely familiar to all of them.
I think you are also worried about the distinction between a formal definition in natural language and a formal definition in a formalized language. The practice in contemporary mathematics, and especially in mathematical logic where the issue arises, is to use natural language whenever possible, especially when studying concepts that don't depend much on the manner in which they are translated into formal languages. So, for example, although Manin's definition of a function may superficially appear "more formal" than a definition from an analysis book that uses natural language, this is only an illusion. — Carl (CBM · talk) 13:47, 7 October 2007 (UTC)

Carl: Please read the post from DGG about 2 paragraphs above. I think he would disagree with you. The trick is to find an effective slant. One thought is to call it "Function (mathematics): rules". Another is to give extended examples: "Function (mathematics) examples". Also, you didn't quite answer my question -- I asked if I should trash it.

(I read the main article carefully last night, as much as I could tolerate): I know you're working hard on it, but my criticism continues to stand. It's a plethora of definitions, a veritable link-fest. I learned a trick from the consensus-writing of international standards (we were all industry competitors, worse than cats in a bag, but I never saw hard feelings): Define your terms in a section up front (or at the end... the standards do it at the front). We spent as much time there as in the body of the standard. Then expand the text using the now-agreed-upon words.

The article needs drawings (I'm good at it, but prefer input up front so as not to waste my time); not everyone is a verbal/written-word learner (I'm not. Ditto for my daughter: we're visual and kinesthetic learners. A guy that sat in the cubicle next to me talked to himself as he worked on Excel. After my daughter had done poorly on a test in high-school elementary calculus, I suggested that she try to visualize and draw the notion as a picture. I never heard another word, and she aced high school and college calculus).

Another trick learned from the business-world: know your customers and get up-front input. Ultimately (better now then later, believe me) the article topic (not just the definition) and the article itself, needs comment from a broad spectrum of user-individuals -- students, teachers of all sorts (6th grade on -- my 6th grade nephew showed me his math text, and gave me a problem they were working: I was stunned at the abstractness of it). I have given some thought to requesting teacher input from our high school. But my guess is, the ideologues would scorn it and the effort would be a waste for all. For a poster-child example of writing for various audiences, please see what happened at Talk:busy beaver. BillWvbailey 14:48, 7 October 2007 (UTC)

I'm not convinced that DGG has much experience with mathematics articles on WP; I read his comment with some skepticism. I don't think you need to trash the article if it will be a useful reference for you in the future, but I also don't think it's good to have a fork of the main "function" article like the one currently there. Rather than nominating it for deletion, I asked if you would be willing to move it into your user space, where you could continue to work on it and I would be less concerned. If you don't know the "slant" (I would say "topic") of the article, how can you write it, and how can we expect a reader to understand it?
The current version of Function (mathematics) is not so bad as to be unreadable. Input on it from many people is certainly valuable; encourage them to leave concise but specific comments on the talk page. If you look at the previous version of the article that I linked on the talk page, you'll see that I did have slightly more info on the definition than the current version does. But not every link needs to be replaced by its definition; at some point, we have to assume the reader will use the links to research unfamiliar terms. — Carl (CBM · talk) 15:13, 8 October 2007 (UTC)

RE readibility of article: It is not unreadable, in fact it is quite readable in the prose sense ... up to a point (about 1000 words). That's why I gave it a B, I should have stated that. Then what happens to us visual learners: our eyes glaze over with all the text and defintions and links. We get impatient and frustrated, and unless we are really compelled to read (by strong interest or necessity), we stop reading and go hunting for, what we would call a better source, one that matches our learning "style" (capabilities might be a better word).

RE moving page: Yes, I will move it. I do want to keep it as reference (it contains some interesting stuff).

RE slant: I had a slant, but now its gone because of all the criticism. I'm trying to be constructive here, I'm trying to modify my slant to aid the article ... BUT I'm not sure anyone (including yourself) feels this is necessary, excepting me. So ... I'm asking you for your opinions and recommendations here: (1) Should the article have extensions? (2) If so, what do you believe should they be? A couple notions have been suggested: (a) More history (nahh, what's there is enough (just needs fact-checking) unless suddenly it explodes into something fascinataing. Plus I don't read German and almost all the deep research of this will be written in German). (b) Extended examples with drawings etc. (Yeah?), (c) Extended word-defintions page (i.e. of all the words used in the article, in particular the set-theoretic ones, with illustrative drawings, not the link-fest). Thanks, BillWvbailey 15:48, 8 October 2007 (UTC)

My general opinion is that extensions of an article are most appropriate when the corresponding section of the original article grows too long and needs to be pinched off to a separate article. I don't see that problem in the function article right now; the sections are all of a manageable length. An extension that arises independently needs to do so as a pretty good article (say B class); otherwise, we could just have a paragraph in the original article about it.
I do think the introduction needs to be pruned some to make it more readable.
I don't understand what you mean by "linkfest". Which section of the article are you looking at? The wiki style of writing does assume readers will use the links to check some definitions; we can't reproduce all of them every time we use them. I do tend to include the most relevant definitions when I expand articles (see Diagonal lemma). — Carl (CBM · talk) 16:03, 8 October 2007 (UTC)

RE move article: done

RE linkfest: 21 in the first 3 para of the Intro and approx 35 in the history section. I find this distacting, but I'm an old guy with good color vision, so blame it on my failing neurons. I do not believe that linking to dates is a useful enterprise. I suppose a plethora of links does no harm except for those so new to the topic that they loose their place as they descend further and further through down a tree of links. I would move the definition of range and domain and codomain down out of the intro, maybe into a more formal place, as these seem to be, specifically, set theoretic contributions to the vocabulary of the notion/enterprise of "function". For example, neither my father's Uspensky and Heaslet 1939 Elementary Number Theory, nor Hardy and Wright 1938, 1972 An introduction to the Theory of Numbers, contains these words; the word "function" only appears undefined in text. As far as I can see it is a "deeper", older notion that has found set-theoretic support and development as a restricted relation and has therefore adopted its vocabulary. I encountered the word domain in some early 20th C stuff (maybe in Zermelo 1908) but not range, and definitely not codomain. BTW: in the archived stuff on the Talk:function (mathematics) there's my survey of the definitions of "function" and words supporting the notion. You even contributed a couple. I think it was a useful enterprise. Bill Wvbailey 16:49, 8 October 2007 (UTC)

Thanks for your comment. Certainly, around 1900 there were many finitary logicians, but since then the actual infinite has turned up in too many places, and there are not many finitary logicians left. You may be the last.
You misunderstood my example function. No matter what the input, it always gives the same output. But it is a very, very large output.
Suppose, for the sake of arguement, that the universe has a constant k, such that if two particles are within less than k of each other, they are in exactly the same location. And suppose the universe has a number K which gives the total volume of space time. You might think, then, that K/k^4 is the largest number. Not so. We must also consider all of the permutations of that number, and then permutations of those permutations.
However, as I said, the old game of "what's the largest number you can write on one side of a 3" x 5" index card" is just for fun. The real mathematical uses of the actual infinite are much more profound, and thus more satisfying. Unfortunately, they are hard to explain to a non-mathematician. Not, please note, impossible to explain. Have you got a year or two to devote to the subject? Rick Norwood 21:41, 14 October 2007 (UTC)


Please don't think that I was trying to brush off your comment there. I do think it is important for our articles to be accessible; I think we may disagree about the role that links to other articles should play in that. I do think we could add some more detailed background to the tautology article, just not in the lede. I added some more background there, and more could be added.

I also started exploring the links to try to make sure they would actually be useful. I edited valuation (mathematics) some and made structure (mathematics) into a disambig page as a result of that. Then I realized the propositional formula was really bad, so I am going to work on that article over the next few days. If you are interested in propositional logic, maybe you would like to help with propositional formula? I could use some help with that, since it's such a fundamental topic. — Carl (CBM · talk) 00:42, 23 October 2007 (UTC)

I didn't think you were trying to brush me off. I agree with you that tautology is a "formal" notion. But it apparently has different meanings.... I'll leave some thoughts on the article page. I'll look over propositional logic and propositional formula and see what what I can do to contribue there. Bill Wvbailey 15:29, 23 October 2007 (UTC)

Propositional formula with feedback[edit]

I read the two sections you added today. I think there is a small confusion there. A propositional formula, as normally defined, cannot be self referential. It's possible for a Boolean circuit to have feedback, by connecting an output to an input. But it isn't possible for a propositional formula to refer to itself, because the truth of a formula is defined indctively given a fixed variable assignment, and that variable assignment must be completely specified beforehand.

The simplest mathematical formulation I can see to achieve that would be to consider a sequence of truth assignments, where each assignment after the first replaces the value of a fixed propositional variable by the truth value of the overall formula under the previous assignment.

Is the terminology "self referential formula" actually used in engineering (it wouldn't surprise me)? We need to handle this carefully, since it's actually a misnomer. — Carl (CBM · talk) 18:49, 31 October 2007 (UTC)

I hear you about that particular inductive definition. But I am very concerned about that definition (I found it in Enderton). In that definition the OBJECT e.g. (a & b) acquires that name "(a & b)". The definition I used on my user page indeed makes assignments that are used by engineers and computer folks (i.e. the =NOT(A1) actually returns a value { "TRUE", "FALSE" } into square e.g. A2 that is both an object and a variable):
(1) If a is a variable [or a constant], then a = (a) is a formula; (2) If a and b are formulas and vi are variables then ~(a)=vi and (a □ b)=vi is a formula (where □ represents ~, &, V, →, ←→, | etc). (3) Only (1) and (2) define formulas.

As the impredicative section shows, the problem exists. As an engineer I just put the weirdness to work, and inconsistency as the truth-table example shows really is not a problem. I'm open to debate here. It sounds like, where the problem comes may be in the definition of "formula". wvbaileyWvbailey 19:15, 31 October 2007 (UTC)

Yes, I think that the definition of formula is the issue here. In your comment above, I don't know what you mean by the = sign. I didn't bring up the section on impredicative definitions in my previous comment, but I was going to say I don't understand it. It talks about impredicative natural language statements, rather than propositional formulas. And indeed, propositional formulas can't be self-referential, so the natural language statements cannot be translated into propositional formulas. — Carl (CBM · talk) 19:19, 31 October 2007 (UTC)

The equals sign is a primitive notion, in the metalanguage "assignment" as in "put in place xxx" where xxx is a symbol that identifies the place (or object), or "assign the symbol 'vi' ". An impredicative definition is just another assertion, just another kind of "proposition". I don't see how anyone could argue that "This sentence is a falsehood" is not an utterance (assertion, proposition). Or "That sentence is not compound, but this sentence is". Again, we must be dealing with definitional issues here. I am trying to get to the broadest defintions, the least restrictive, the most flexible, that I can find. With this approach all sorts of interesting things begin to happen. The engineering books present the "propositional calculus" in terms of the symbols and the truth tables and then just skitter straight ahead without a beat into the notion of feeding back variables etc. Are there actually two "caluculi" here with different premises? It would seem so ... Bill Wvbailey 19:38, 31 October 2007 (UTC)

In the mathematical definition of propositional formulas, there is no equals sign (the same definition is used in Kleene 1967, Enderton 2002, and pretty much every other math book since 1967). A propositional formula, in this definition, is built from propositional variables using logical connectives, and so it can't contain an equals sign. Could you point out the sort of engineering book you are looking at, so I can look it up? One that's well regarded would be best.
Definitely "This sentence is false" is an utterance - but it is not an utterance that can be faithfully translated into a propositional formula. — Carl (CBM · talk) 19:45, 31 October 2007 (UTC)

I've got McCluskey as a reference (see the article page). I don't know if he's still in print: cf pp. 184 ff for a discussion of "stable and unstable states". I have others as well. One thought is, to hide the stuff if it really bothers. I'm just putting out my take on the topic, which is not a mathematician's, to say the least. Problem is, there seems to be more to "propostional formula" than the mathematician's version. Also the drawing I just pasted in may bother because of the "axioms" in it (they do work, as shown in the drawing). If that bothers, hide it too. What I've run into is two approaches, the "axiomatic" and the "truth-table" methods. There definitely is an axiomatic method that uses " = "(Huntington cf Suppes 1957 p. 204). Bill Wvbailey 20:01, 31 October 2007 (UTC)


McClusky is in the library on the other part of campus, so it will take me a day or two to get over there to get it. But I will look it up. I'll also look up Suppes.

I have an idea for how to deal with the feedback, by just being more explicit. First the article should mention the relationship between propositional formulas and boolean algebra. The point is that any propositional formula can be implemented in a boolean circuit. Then it can mention the fact that, unlike with formulas, it is possible to take a wire from the output of a digital circuit back to its input. This feedback can sometimes lead to instability (for example, if the output of a negation is fed back to its input). But it can also sometimes lead to stable configurations, such as flip flops.

I still don't follow the section about impredicative definitions, though. — Carl (CBM · talk) 20:08, 31 October 2007 (UTC)

I pulled Suppes 1957 from the library. His definition of first-order formulas is on p. 54, and I don't think he defines propositional formulas at all. On p. 204 there are some identities for Boolean algebra of sets, but nothing about self reference.
You are completely right that it is possible to have a deductive system for propositional logic; Kleene 1967 gives one. What I need to learn about is a sort of system of recursive definitions in which each propositional variable is allowed to name another formula. It's intriguing. For example, if p = q and q = p, what would be the truth value of the formula p in such a system? fascinating. — Carl (CBM · talk) 20:33, 31 October 2007 (UTC)

If p = q and q = p then you have the equivalent of two NOTs with feedback: ~(~p)=p . Engineers say this "latches up" -- it has two solutions. If you use true Boolean logic ~p = 1-p, then (1 - (1 - p) = p then either 0 or 1 are solutions (!). Actually it's creepier than this. Any number will satisfy p = q and q = p.

Your suggestion is fine with me.

You are correct about Suppes not discussing self-reference (I guess I misunderstood your question); I have found nothing but the tangential reference in McCluskey about this self-reference business. However, it is standard operating procedure to build "flip-flops" this way (that's what he'll be talking about in the book).

What I am proposing in the impredicate definitions is that these yield (or are identical to) the "feedback" issues dealt with in that section (my example being (p V a) = q means that symbol q is defined in terms of p and a and the OR). But when q connects back to p, then q is in fact defined in terms of a, itself and OR, so it is impredicative. (Whether that is a TRUTH or not, is another question. I stumbled on the paradox of the example as I was noodling this.)

I find the Suppes thing really interesting -- it is an axiom set close to the set in the article Boolean algebra (structure) also derived from Huntington but at a later date (Suppes is referencing Huntington 1908). I tested the Suppes version out last night and decided that axiom set indeed works, so I put something like that in for the "stroke" (still in the drawing). Also, I looked at the abstract algebra version of a Boolean algebra [?] and it seems to require EXCLUSIVE-OR and the AND (a ring with idempotency) and I'm not sure that this Boolean ring yields a Boolean algebra (or however you say it) (i.e. are XOR and AND sufficient? I don't believe so). I've also got another book by Robbin 1969, 1997 that I need to look at.
A thought about the axiomatic approach: the truth-table approach is so easy that it fell into disuse. Halloween is just about here, gotta go. Bill Wvbailey 20:53, 31 October 2007 (UTC)

Two articles[edit]

I saw your message about Richard's paradox and Hilbert-style deduction system, and I do have those articles in mind. It's just taking me a little while to get to them. — Carl (CBM · talk) 12:53, 14 November 2007 (UTC)

Let me know if you need any help. Bill Wvbailey 14:56, 14 November 2007 (UTC)

Three approaches to Hilbert calculi[edit]

Dear Bill,

Thank You for warning me the need of rewrite, and also for the proposals and the comments. Sorry for that I have not replied at once. I wanted to reply with a concrete proposal, which I eventually mentioned on Carl's talk page. Thank You also for summarizing Kleene's appraoch. Unfortunatelly, I know few about Hilbert calculus. I know about three aproaches, I write them on the talk page of the article.

Best wishes,

Physis 14:05, 15 November 2007 (UTC)

Duplicate images uploaded[edit]

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Standard model[edit]

Usually, when someone writes down a a set of axioms, they have in mind some intended model for the axioms. But a first-order theory can never completely describe an infinite model, so the theory will have other models as well. The model that was originally intended is called the standard model. The standard model of arithmetic consists of the natural numbers with their ordinary arithmetical operations, and the standard model for set theory consists of all sets with the ordinary membership relation. These models are defined at the meta level - you have to already know what you mean by "natural number" in order to know what the standard model of arithmetic is. — Carl (CBM · talk) 01:32, 14 December 2007 (UTC)

"Big Fat Footnote"[edit]


Thanks for the Big Fat Footnote in the Hilbert article. I knew there was a good, interesting story there but didn't have the time/resources to drag it out. (John User:Jwy talk) 20:29, 15 December 2007 (UTC)==Image copyright problem with Image:OLPC guitar probe coil 3b.jpg==

Image Copyright problem

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'self' Image deletion[edit]

If I get the gist of the question, just put a {{db-self}} on the image; the sysop will check that the template placement was actually done by the author, and then delete it. If it's used on any articles, they may double-check with the author, but that should take care of the unwanted/needed image. SkierRMH (talk) 17:08, 26 May 2008 (UTC)

Brouwer-Hilbert controversy[edit]

Hi, Thanks for your comments. I added a slightly modified version at the new page. Please feel free to edit. I find the material fascinating but unfortunately lack background. Katzmik (talk) 13:45, 10 September 2008 (UTC)

Thanks for all your edits at BHC and the research that must have gone into it. You did pretty well for a non-mathematician, perhaps better. If you like you can try your hand at non-standard analysis, non-standard calculus, etc but be warned that this is decidedly non-finitist. Katzmik (talk) 11:13, 16 September 2008 (UTC)
The section starting with a philosophical defeat, etc is somewhat informal in style. Could you try to eliminate solecisms when you get a chance? Katzmik (talk) 13:25, 23 September 2008 (UTC)

John W. Dawson, Jr[edit]

Hi, I have not been able to track this fellow down. I think I saw at Amazon that he is supposed to be at UPenn math department but he is not. The problem is that there are A LOT of people named John W. Dawson. A fellow who knows as much as he does about Goedel, Hilbert, and the likes deserves a wiki page of his own in my opinion. Katzmik (talk) 12:59, 16 September 2008 (UTC)

I already created a page for him. He is at York, not the main branch of Penn State. Katzmik (talk) 11:19, 17 September 2008 (UTC)

You can certainly contact him if you wish to add things to his page, or ask any questions about his books. I wouldn't do it in my name though. Katzmik (talk) 14:36, 17 September 2008 (UTC)
Incidentally, Brouwer-Hilbert controversy is enjoying in relative terms a spectacular success at wiki traffic statistics. Katzmik (talk) 14:38, 17 September 2008 (UTC)

completed infinity[edit]

Hi, I notice that this page is only a redirect to infinity, whereas the latter page says nothing at all about completed infinity. My impression is that "completed infinity" is a term that has a very specific meaning in the context of 19th century foundational controversies, Cantor, Kronecker, etc. Wouldn't it be appropriate to have such a page? Katzmik (talk) 15:45, 17 September 2008 (UTC)

My hero![edit]

This says it all. siℓℓy rabbit (talk) 15:50, 15 October 2008 (UTC)

More on Brouwer-Hilbert controversy[edit]

Hi, Thanks again for your comments there, there is a lot to think about. I have been thinking of your comments on my talk page. I feel that to develop this page further would require a significant investment of my time. I may be prepared to make such in investment into the work of a research article but it is hard to motivate myself in the framework of a wiki page. If you are interested we can look into this area to see if there is publishable material here. Incidentally, Bieberbach was a student of Hilbert's. Katzmik (talk) 10:38, 26 October 2008 (UTC)


Interesting combination of people there, now that you point it out!

My understanding about the Stegner controversy was that people felt he should have made it clearer in the novel that he was borrowing as much as he did. I haven't let it worry me much!

I suspect that you are correct about what the phrase "without numerical results" is about, but we know more about the guy than a significantly large (I won't give a number ;-) ) percentage of wikipedia users. Most won't understand that. If our understanding is correct, it would be good to fill in the information as it shows how abstractly consistent he was in diverse fields of math. I just haven't had the time to dig up the details.

Our trajectories have been similar: I went to school in Maine and ended up here, down the road from Stanford. I didn't pursue as many degrees or spend as much time with hardware (although I still own, with my brothers, 1/3rd of a PDP-11 with a teletype keyboard). Cheers, (John User:Jwy talk) 00:00, 16 January 2009 (UTC)

I was clearing space for a new bookcase and stumbled on my Reid. Have done the "filling in" of the information mentioned above. I occasionally consider putting in a push to get our friend David to featured status. (John User:Jwy talk) 01:36, 16 January 2009 (UTC)


There is (was?) one but it's in a bulleted list, hence neither a problem, nor indeed needed. Rich Farmbrough, 00:47 19 January 2009 (UTC).

Disputed fair use rationale for File:IMG 2511 edited-1 teapot dome Oil Weekly.jpg}[edit]

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Disputed fair use rationale for File:IMG 2511 edited-1 teapot dome Oil Weekly.jpg}[edit]

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Fair use rationale for File:IMG 2512 edited-1 Teapot Dome Literary Digest.jpg[edit]

Thanks for uploading or contributing to File:IMG 2512 edited-1 Teapot Dome Literary Digest.jpg. I notice the file page specifies that the file is being used under fair use but there is not a suitable explanation or rationale as to why each specific use in Wikipedia constitutes fair use. Please go to the file description page and edit it to include a fair use rationale.

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That's a terrible shame- if they were published only a couple of years earlier, they would be public domain. Anything published before 1923 can be considered PD in the U.S.. I'm assuming the images are being used to illustrate the rock? Per our non-free content criteria, non-free images can only be used if there is no possibility of a free image being located or created. Is there any reason that someone couldn't simply go to Teapot Dome and photograph it themselves? J Milburn (talk) 20:09, 25 January 2009 (UTC)
Yeah, that would probably be the best option. I'm not actually that good on the details of public domain, but images may fall under this template (I believe there's a copyright office database that's checkable) or perhaps even this one (that would apply if there's no copyright notice anywhere on the magazine, I believe). If not, then you'll have to wait until the fall into the public domain for any other reason. See this page for a list of potential reasons. Alternatively, a lot of pictures from the U.S. government are public domain- that article already contains one, it may be possible to find others. Perhaps your best bet for help with that would be Wikipedia talk:Public domain. However, if the images cannot be determined to be public domain, they should not be used, as they would be replaceable with a free image of the rock. Thanks for understanding. J Milburn (talk) 20:28, 25 January 2009 (UTC)
Normally, you can tag the images with {{db-author}} for them to be deleted quickly if you were the uploader, or, alternatively, you could wait a few days until they are deleted for the reasons on my tag. In this case, I'll delete them for you. J Milburn (talk) 16:35, 26 January 2009 (UTC)
Oh, and I've just noticed, the "this page" above should have linked to WP:ICT/PD. J Milburn (talk) 16:35, 26 January 2009 (UTC)

That's great! Remember that permission has to be to release an image (perhaps into the public domain, perhaps under the GFDL, and there are other licenses- Creative Common Attribution ShareAlike 3.0 is another favourite) and not merely for Wikipedia use. If you get email permission, reupload the images, tag them with {{OTRS pending}} and forward the email to the address given here, along with a note about where the image has been uploaded onto Wikipedia. Then, the email permission is stored by the Wikimedia Foundation, and no one will challenge it. Good work, let me know if I can be of any further help. J Milburn (talk) 21:32, 26 January 2009 (UTC)

Image copyright problem with File:Function machine5.png[edit]

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Turing machine and algorithm[edit]

I also thought those edits were not so good, mainly because they did not fit with the rest of the articles they were in. But it didn't look like self-promotion to me, since the book cited is a Dover reprint. The non-standard terminology that book happens to use is unfortunate for a learner, and could also make the edits seem more strange. — Carl (CBM · talk) 02:04, 3 July 2009 (UTC)


I was somewhat dismayed that you changed the references on that article to footnotes. The comments at the GA review were simply wrong; it would have been fine to just make all the inline references express the page number in the same way. Do you mind if I switch it back on my own time? There is a general admonition that articles shouldn't change from one style to another unless everyone agrees, and I don't really agree with switching to footnotes. — Carl (CBM · talk) 14:39, 22 August 2009 (UTC)


Thanks! Function (mathematics) is quite impressive, although it does contain strange things like "Logicians of this time were primarily involved with analyzing syllogisms"

Oh dear it was you who wrote it [2] (see my talk page). What's wrong with "Logicians of this time were primarily involved with analyzing syllogisms". Well (1) the style is what I call '1066-ish', i.e. summarises long or significant periods in history with a curt or risible generalisation and (2) it is factually wrong as traditional logic is mostly not about the syllogistic at all but about reasoning generally, about semantics (the so-called logica vetus is primarily about the semantics of terms and propositions - this is because the early medieval logicians were missing Aristotle's Prior Analytics, not generally available until the early 13C). If you look at the index of Mill's System of Logic published in 1843, you will see there is very little about syllogisms. Which reminds me I have entirely omitted Mill, whose book was influential at the time, e.g. upon Frege.

Notwithstanding, that article is an impressive piece of work and you deserve credit and congratulations for it. I have made a few minor copy edits [3].

I have incorporated the new material into History of Logic. There is much to do, but I fear that as I shall shortly be banned (I am a sockpuppet of a user banned for 'political' offences on the wiki) that someone else shall have to continue this work. Logicist (talk) 08:03, 23 August 2009 (UTC)

[edit] Looking again at the section on "The logician's "function" prior to 1850" I think it is overly simplistic. As far as I know, no logician prior to Frege would have imagined that propositions could be expressed in functional form. The traditional analysis is the 'compositional' theory that subject and predicate are combined (or disjoined) in the proposition to express what is the case, or what is true. Thus there are four possibilities. 'Quoniam autem est enuntiare et quod est non esse et quod non est esse et quod est esse et quod non est non esse'. You can combine subject and predicate in a way that reflects reality (a crow is black), you can combine them in a way that does not (a crow is white), you can disjoin them in a way that is the case (a crow is not white), or in a way that is not (a crow is not black). Truth is 'being the case', truth and existence are convertible 'unumquodque se habet ad esse, sic se habet ad veritatem'. Frege is the first logician (as far as I know) to replace this compositional subject-predicate explanation with the functional one. The functional one makes truth a value that a propositional function can have.

The section in question needs to explain this idea more fully, carefully. I would help, but as I mentioned above my time here is limited. Logicist (talk) 08:50, 23 August 2009 (UTC)


Euler Diagrams communication

You wrote to me (Dagme):

"Feel free to contact me on my talk page if you run into any other problems."

Is this what you had in mind? I don't see any instructions on how to send messages.

I saw your new historical section on the Euler Diagram page. I am looking into Euler and Venn Diagrams with a view to suggesting revisions again.

I think a good first step would be to revise the pages separately with references to each other. At a certain point, contributors can decide whether the pages should be merged.

Here is an article which may be of interest to you:

I prefer to correspond by email, so let me know if you are interested in an email correspondence.

Dagme (talk) 22:31, 22 November 2009 (UTC) —Preceding unsigned comment added by Dagme (talkcontribs)

How does a user enter mathematical symbols into a Wikipedia article? Can I use TeX, Scientific Workplace, or MathType for this?

Dagme (talk) 22:54, 23 November 2009 (UTC)

Thanks for your comments on math symbols. What about producing a pdf file? Can a pdf file be uploaded directly to

Dagme (talk) 18:25, 24 November 2009 (UTC)

What I usually do to give a math document to someone who does not use TeX or Scientific Workplace, is to create the document in Scientific Workplace and then export it as a pdf file. The quality is just fine. Also, images can be inserted into the document at the Scientific Workplace stage. For this reason, my idea is to generate the entire Wikipedia article in this way. I don't know how to insert images directly into a TeX or LaTeX file, so I can't help with this method if you don't have Scientific Workplace. However, you CAN do this with Word, so if you use MathType, you can do pretty much the same thing I described to get a pdf file. Maybe you can even use Word directly, but I don't know about that. Word with MathType is very cumbersome for me, so I would rather use Scientific Workplace as I described above.

Dagme (talk) 23:10, 24 November 2009 (UTC)

Gödel's incompleteness theorems[edit]

Hello, Gödel's incompleteness theorems is only a c because it lacks inline citations. I am certain that the lack of references is the article's biggest problem at the moment. Pollinosisss (talk) 16:37, 1 December 2009 (UTC)

The article has quite a few inline citations in Harvard reference (author and year) form. Not as many as are the fashion here on the English Wikipedia, but just about what would be considered the ideal density on the German Wikipedia. (There I once had to reduce the footnote density of an article considerably to get it accepted as a Good Article.) Are there any specific claims that you think need a citation? Hans Adler 20:28, 1 December 2009 (UTC)
I feel rather silly. I had simply taken a quick look for references at the bottom of the article. I changed the class to a b. Pollinosisss (talk) 21:08, 1 December 2009 (UTC)
Absolutely no need to feel silly! Some of the mathematics articles are a bit eccentric in this respect, so this is not the first time something like this has happened. Hans Adler 21:26, 1 December 2009 (UTC)

function (mathematics)[edit]

Perhaps the quote on Oresme is more useful? Tkuvho (talk) 16:11, 24 February 2010 (UTC)[edit]

do you have the excel file? —Preceding unsigned comment added by Fulldecent (talkcontribs) 18:29, 26 March 2010 (UTC)

Function (mathematics)[edit]

Hi, it seems that you have an access to the following book:

Eves, Howard. (1990), Fundations and Fundamental Concepts of Mathematics: Third Edition, Dover Publications, Inc. Mineola, NY, ISBN 0-486-69609-X (pbk) Check |isbn= value: invalid character (help) 

I'm working now on the article ru:Спор о струне (Vibrating string controversy), and I'm very interested in the history of notion of function to provide some background for this article. Unfortunately, Google Books preview does not contain page 234 of Eves, which I'm most interested in. Would you be so kind to send me the scan of this page via e-mail (

Thanks! Ilya Voyager (talk) 22:24, 17 April 2010 (UTC)

teapot dome picture[edit]

awesome. Decora (talk) 22:37, 17 April 2010 (UTC)


Just a note, I moved your comment to here where the discussion was moved. — Carl (CBM · talk) 02:46, 10 May 2010 (UTC)


This might interest you: [4]. (talk) 07:00, 1 June 2010 (UTC)

I've seen this referenced but never seen it up close and personal. So I took the opportunity to order it and Volume III of Kurt Goedel's Collected Works from Amazon. Thanks. BillWvbailey (talk) 17:34, 1 June 2010 (UTC)

You are now a Reviewer[edit]

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Hello. Your account has been granted the "reviewer" userright, allowing you to review other users' edits on certain flagged pages. Pending changes, also known as flagged protection, is currently undergoing a two-month trial scheduled to end 15 August 2010.

Reviewers can review edits made by users who are not autoconfirmed to articles placed under pending changes. Pending changes is applied to only a small number of articles, similarly to how semi-protection is applied but in a more controlled way for the trial. The list of articles with pending changes awaiting review is located at Special:OldReviewedPages.

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If you do not want this userright, you may ask any administrator to remove it for you at any time. Courcelles (talk) 18:53, 17 June 2010 (UTC)

Moved section on incompleteness theorems[edit]

I moved the section you started on the incompleteness theorems talk page to the arguments page. When you started that section, it was directly about improving the article, but since then it has (again) turned into just another discussion of Wittgenstein. Please don't take any offense; your editing and attention to sources have improved that article significantly. — Carl (CBM · talk) 23:57, 15 August 2010 (UTC)

Jean van Heijenoort v. Jean Van Heijenoort[edit]

I notice that you've recently amended my insertions of links for Jean van Heijenoort, with edit summary "van Heijenoort is spelled with a small v". I've had arguments about this in the past, which have left me persuaded that, in general, the matter is not always clear-cut. In the case of JvH, you can see from the history that the article was originally called Jean van Heijenoort, and moved to Jean Van Heijenoort in August 2006. So I suggest that either

  1. if you're sure you're right, and are willing to defend that view, move the article back to its original name, or
  2. let the matter lie, as not being sufficiently important to worry about.

Either way, piecemeal modification of links like you have been doing is not the best policy. SamuelTheGhost (talk) 15:50, 6 January 2011 (UTC)

Thanks for your reply. It's clear from it that option 1 above applies, so please move the article as I suggested. Article titles in Wikipedia are in generally lower-case except for the first word, so if you're right, the article should definitely be called Jean van Heijenoort as it was before August 2006. SamuelTheGhost (talk) 19:52, 6 January 2011 (UTC)
I see that CBM has now done the move, so I trust that you are content. SamuelTheGhost (talk) 18:13, 10 January 2011 (UTC)

Photo for forward converter article[edit]

Thanks, but this is not I need :(. I need photo actual FC (not scheme) to replace this unlicensed image. -- Bojan  Talk  10:12, 18 January 2011 (UTC)

How You would distinct small generator from bigger motor? I admit, power electronics is not my field of interest. Students wrote those few articles, and I would like to put free equivalent, if it can be made, cause their professors should evaluate students' works. It would be nice if can you take picture of that what you have 'cause readers that are not acquainted with topic may also appreciate additional photographies. -- Bojan  Talk  20:11, 18 January 2011 (UTC)

Kleene's T predicate[edit]

I did see your question on Talk:Kleene's T predicate, but I only had time to respond to it today. — Carl (CBM · talk) 21:18, 22 January 2011 (UTC)



Any chance you could take a look at this ? I have replaced contradict tag with expert needed but as you commented I thought I would give you a heads up.

Chaosdruid (talk) 23:21, 2 February 2011 (UTC)

Talk page butchery (Principia Mathematica)[edit]

Please don't chop up my comments on Principia Mathematica Talk, as it destroyed the original flow (granted, there wasn't much flow originally) and also made the signature near-impossible to follow. That was really not cool, and strongly discouraged in the future. SamuelRiv (talk) 00:40, 24 February 2011 (UTC)

IRC invitation[edit]

Because I have noticed you commenting at the current RfC regarding Pending Changes, I wanted to invite you to the IRC channel for pending changes. If you are not customarily logged into the IRC, use this link. This under used resource can allow real time discussion at this particularly timely venture of the trial known as Pending Changes. Even if nothing can come from debating points there, at least this invitation is delivered with the best of intentions and good faith expectations. Kind regards. My76Strat 08:55, 2 March 2011 (UTC)

Zach paper[edit]

You might like this.[5] It's been around for a while and I somehow thought it had come up in some logic article but I don't see any references to it. Maybe you can use it someplace. (talk) 09:09, 2 May 2011 (UTC)

A quick scan of this pre-print leads me to believe it will be quite useful. I've had trouble finding info about some of the topics mentioned, e.g. Russell's "theory of types". Thanks, Bill

File:Function machine5.png[edit]

Hi! I'm interested in the image mentioned above: is it created in some kind of vector image editor/diagram editor? I'd like to translate this image into Russian, and therefore I need a source file of it. If it is available, could you please upload it or send it me via e-mail mentioned on my ruwiki talkpage? Thanks! Ilya Voyager (talk) 13:34, 10 May 2011 (UTC)

A questiion to user Wvbailey[edit]

Dear Mr. Wvbailey,

This is Dan Teplitskiy, whose paper was moved by you to talk section of Russell's paradox article. Could you please point to some flaws in English you indentified while reading it? I am not an English speaking person and would be very obliged if you give me some quick hints on the language issues regarding my paper.

Thanks a lot in advance!


Dan — Preceding unsigned comment added by Daniil Teplitskiy (talkcontribs) 16:10, 4 July 2011 (UTC)

File:IMG 3252 Hamilton 1860 p 180 long Euler.jpg listed for deletion[edit]

A file that you uploaded or altered, File:IMG 3252 Hamilton 1860 p 180 long Euler.jpg, has been listed at Wikipedia:Files for deletion. Please see the discussion to see why this is (you may have to search for the title of the image to find its entry), if you are interested in it not being deleted. Thank you. Alpha_Quadrant (talk) 22:49, 9 December 2011 (UTC)

File:IMG 3267 Venn example.jpg listed for deletion[edit]

A file that you uploaded or altered, File:IMG 3267 Venn example.jpg, has been listed at Wikipedia:Files for deletion. Please see the discussion to see why this is (you may have to search for the title of the image to find its entry), if you are interested in it not being deleted. Thank you. Alpha_Quadrant (talk) 23:30, 9 December 2011 (UTC)

File:IMG 3269 Couturat's Venn diagram.jpg listed for deletion[edit]

A file that you uploaded or altered, File:IMG 3269 Couturat's Venn diagram.jpg, has been listed at Wikipedia:Files for deletion. Please see the discussion to see why this is (you may have to search for the title of the image to find its entry), if you are interested in it not being deleted. Thank you. Alpha_Quadrant (talk) 23:32, 9 December 2011 (UTC)

You are invited to join Stanford's WikiProject![edit]

View of Hoover Tower from Main Quad.

As a current or past contributor to a related article, I thought I'd let you know about WikiProject Stanford University, a collaborative effort to improve Wikipedia's coverage of Stanford University. If you would like to participate, you can visit the project page, where you can join the project and see a list of open tasks and related articles. Thanks!

ralphamale (talk) 22:10, 24 January 2012 (UTC)


Thank you for your contribution to the lead on Inductance. I'm sure that you intended it as an edit in good faith, but did you check the talk page? I have (at least temporarily) reverted it for now. The reason is that the lead of the article has been discussed at some considerable length on that talk page. It has taken quite a while to reach some sort of concensus and agreement (and it isn't entirely universal). I note that you haven't changed much of the basic concept, but I would argue with the inclusion of Oesterd's law as inductance as a phenomenon owes nothing to a steady state magnetic field. Around half of the talk page discussion is on this very point alone.

You are, of course, entirely welcome to contribute, but in the interests of peace and harmony, please raise it on the talk page first.

Regards, (talk) 16:07, 8 May 2012 (UTC)

I am using the wikipedia Bold, BRD method (i.e. Be Bold, Revert, Discuss). You are apparently new to wikipedia (an unregistered editor), so this methodology may have escaped you. See the talk page. Bill Wvbailey (talk) 16:31, 8 May 2012 (UTC)
No I'm not new. I take your point. I have commented on your contribution, but I note that a fellow editor has already disagreed with me. His priviledge, I guess. <sits back and awaits the inevitable bun fight.> (talk) 17:02, 8 May 2012 (UTC)

DR notice on Commons[edit]

Hi! One of the files you uploaded here on en-wiki was moved to Commons long ago. It has now been nominated for deletion. Feel free to Comment on Commons:Commons:Deletion requests/File:Canongate plaque 1.jpg. --MGA73 (talk) 08:30, 28 July 2012 (UTC)

Looking for source file of images[edit]

For the purposes of vectorizing and editing your image(s), I'm asking for your help in uploading source files for the following images: File:Function color example 3.gif File:Function_image_and_preimage_3.png File:Function_with_two_values_1.png

If you want to assist me, please upload the original source files created in Autodesk Sketchbook Pro to this site: (see the scope of the project here:

When/if you upload the source files there, please alert me here or on my talk page.

Thank you in advance.

I dont know what versions of autosketch software you've been using, but does it have a native format (DXF, SKD, EPS, PS, PDF, basically anything that IS NOT an raster image)? If so those files may be useful for me to start from. If you don't have the originals I will try to redraw in Inkscape from scratch. I wasn't trying to indicate anything negative about the software choice, to the contrary, what you use (AutoDesk software) is an Vector Editor to begin with, so its merely a matter of the output format used and its conversion. Hope you follow (respond here or on my talk) Zerodamage (talk) 08:43, 14 August 2012 (UTC)
Seems my autodesk knowledge was a bit out of date, I will convert them manually to SVG's then. Bye for now Zerodamage (talk) 15:17, 14 August 2012 (UTC)

Bailey. I need your help![edit]

I just read the Turing Machine article that you helped to craft. I need to come up with a set of quintuples for a UTM (ideally just a 10-20 states and 3 symbols) that I can use to demonstrate UTMs to a lay audience. I am working on a project called Complexity Explorer and I have developed some very simple visual models of Turing machines . I have scoured the internet looking for examples of commented UTM's an come up with nothing. I would love to discuss this matter with you and see if you are interested with this worthy project. The resulting model will be of incalculable value to those trying to understand this beautiful idea. Contact me at balwit if you are interested. And thanks for your contributions to a great article on the Turing machine.

Balwit (talk) 18:35, 12 September 2012 (UTC)

Foundation of mathematics article[edit]

Hello. As I saw no means of private contact I mention here that I wrote an explanation for my deletion of the book reference in the talk page of the foundations of mathematics article. Please consider the point, thanks. Spoirier (talk) 22:23, 16 September 2012 (UTC)

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File:Algorithm P-T multiply 2.JPG missing description details[edit]

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Proposed deletion of Algorithm examples[edit]

Ambox warning yellow.svg

The article Algorithm examples has been proposed for deletion because of the following concern:

This article has no clear topic (the title is very vague), and reads less like an encyclopedia article and more like an excerpt from an introductory theory of computing textbook. Even a complete rewrite wouldn't save it, because what would the rewrite be about?

While all constructive contributions to Wikipedia are appreciated, content or articles may be deleted for any of several reasons.

You may prevent the proposed deletion by removing the {{proposed deletion/dated}} notice, but please explain why in your edit summary or on the article's talk page.

Please consider improving the article to address the issues raised. Removing {{proposed deletion/dated}} will stop the proposed deletion process, but other deletion processes exist. In particular, the speedy deletion process can result in deletion without discussion, and articles for deletion allows discussion to reach consensus for deletion. —David Eppstein (talk) 00:46, 5 April 2014 (UTC)

Energy sucking antennas[edit]

Are you the Bill Bailey that coined the term "energy sucking antennas" a long time ago on usenet?Constant314 (talk) 21:17, 3 June 2014 (UTC)

Role of Magnetic Vector Potential in Transformers[edit]

Just because of the references you mentioned on leakage inductance, I thought maybe you might have what I am looking for which is a reliable source for the role the vector potential plays in transformers. I can derive it from Feynman's equations for the vector potential but that would be WP:SYN. It seams this is too simple for anyone writing a physics textbook and too complicated for an engineering textbook which only leaves very expensive books about transformers.Constant314 (talk) 21:44, 3 June 2014 (UTC)

Nomination of Algorithm examples for deletion[edit]

A discussion is taking place as to whether the article Algorithm examples is suitable for inclusion in Wikipedia according to Wikipedia's policies and guidelines or whether it should be deleted.

The article will be discussed at Wikipedia:Articles for deletion/Algorithm examples until a consensus is reached, and anyone is welcome to contribute to the discussion. The nomination will explain the policies and guidelines which are of concern. The discussion focuses on high-quality evidence and our policies and guidelines.

Users may edit the article during the discussion, including to improve the article to address concerns raised in the discussion. However, do not remove the article-for-deletion notice from the top of the article. Dicklyon (talk) 05:05, 10 August 2014 (UTC)

I added my 2 cents to the talk page. BillWvbailey (talk) 22:07, 10 August 2014 (UTC)

abstract machine taxonomy[edit]

Did you base this on some source? JMP EAX (talk) 22:42, 19 August 2014 (UTC)

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ArbCom elections are now open![edit]

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ArbCom Elections 2016: Voting now open![edit]

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