Wikipedia:Articles for deletion/Johnston diagram


 * The following discussion is an archived debate of the proposed deletion of the article below. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review).  No further edits should be made to this page.

The result was redirect to Venn diagram. Consensus for not keeping the page. Since the REFUND requester has asked for redirection, userfication would not be helpful. Previous article history can still be accessed with a redirect. (non-admin closure) f  e  minist  14:20, 20 May 2017 (UTC)

Johnston diagram

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Unsourced and unsourceable — both Google scholar and Google books have zero relevant hits for this concept. It was successfully prodded in 2009 by with the rationale "Original research. Name is only used by Johnston himself, the owner of a dubious website and creator of this article. See talk page for details." but at the request of it has been restored by. Matthiaspaul's request did not ask for it to be placed in article space, only to look at its contents while working on something related. It doesn't belong on Wikipedia now any more than it did earlier. —David Eppstein (talk) 05:12, 12 May 2017 (UTC)
 * Note: This debate has been included in the list of Mathematics-related deletion discussions. —David Eppstein (talk) 05:14, 12 May 2017 (UTC)


 * Userfy to User:Matthiaspaul/Johnston diagram. I should have done that in the first place when I restored it, but now that we're at AFD, it's best to let the community decide. can always request a WP:U1 deletion when he's done with it. ~Anachronist (talk) 18:28, 12 May 2017 (UTC)
 * Userfy to User:Matthiaspaul/Johnston diagram. Thank you for notifying me; I turned the article into a PDF file and downloaded it in case I get nostalgic about the old days. The article has no references, which is not how it should be. Perhaps these so-called "Johnston diagrams" would be more appropriately called "logical Venn diagrams". Looking up "logical Venn diagrams" on Google Images turns up as first hit: https://www.britannica.com/topic/Venn-diagram and as second hit: https://www.jeffreythompson.org/blog/2010/04/18/logic-gates-as-venn-diagrams/. By the way, searching "isomorphism between sets and propositions" turns up page 85 of the book Foundation Discrete Mathematics for Computing by Dexter J. Booth. The Britannica article on Venn diagrams explains that Venn diagrams had always been about logic, from their very inception; so what is all this about Johnston diagrams being the application of Venn diagrams to logic? Searching for "P T Johnstone diagrams" yields a book cover with the title Notes on logic and set theory by P. T. Johnstone and also another book cover: Set Theory and Logic (Dover Books on Mathematics) by Robert R. Stoll. Here is some paper on The Stone Representation Theorem for Boolean Algebras by Matthew Dirks, which mentions Peter T. Johnstone in its references. The paper states in its abstract: "The Stone Representation Theorem for Boolean Algebras, first proved by M. H. Stone in 1936 ([4]), states that every Boolean algebra is isomorphic to a field of sets." Well, enough of such coincidences or seeming coincidences (pareidolia?)... back to what the Britannica article is saying about Venn diagrams. It looks like the mainstream mathematics community calls as Venn diagrams what R. Johnston calls "Johnston diagrams", so any information in the article Johnston diagram that might be worth salvaging could be moved to the article on Venn diagram. 09:54, 13 May 2017 (UTC)
 * And Boolean algebra is the Lindenbaum–Tarski algebra of propositional calculus, so between Stone's representation theorem and the Lindenbaum–Tarski algebra concept, that should be enough to establish a link between set theory and propositional logic. But that is the logical side; the visual side is the Venn diagrams. Enough said. 10:14, 13 May 2017 (UTC)


 * Comment. While there are several places in the web mentioning Johnston diagrams as some kind of "Venn diagram for logic", none of those I saw actually discusses the origin of the term. At least since 2001 the main source of this appears to be Russell Johnston's site LogicTutorial (British Columbia), where these diagrams are also called exclusion diagrams (per http://logictutorial.com/). They seem to refer to earlier work conducted back in 1987. As Russell Johnston dedicated his site to the work of his father Wesley Johnston and John King Farlow (per http://www.logictutorial.com/meaning%20of%20life.html), apparently philosophers as well, it is also possible, that the 1987 work is related to one of them (if this helps to locate primary sources).
 * The German Wikipedia also has a larger section on Johnston diagrams in de:Mengendiagramm. This was added by Austrian de:User:GottschallCh in 2005 . Since he is no longer active in Wikipedia, but can be easily found in the net, I was about to write him an e-mail asking for his sources, but it got delayed due to my lack of time.
 * --Matthiaspaul (talk) 16:52, 13 May 2017 (UTC)
 * This page, however, seems to indicate that Russell Johnston started discussing "meaning as exclusion" in the late 1980s himself.
 * --Matthiaspaul (talk) 21:42, 14 May 2017 (UTC)


 * Redir to Venn diagram. Unless more sources can be found, I suggest to replace the article by a redirect to Venn diagram, as I already proposed for this case when asking for the article to be undeleted . Optionally, the redirect could be tagged with an Rcat such as "R from misnomer" if this would be found necessary. Redirecting this has several advantages over deleting it:
 * Even if unsourced, there are enough mentionings of the term in the web for users to expect some further info on this topic to be found in Wikipedia. Running into a red link is not helpful for them. Using a redirect, we'd at least direct users to the closely related Venn diagram article. As redirects do not need to meet the same notability criteria as articles, but just need to be "useful", this would be perfectly in line with the purpose of redirects per WP:REDIR.
 * The edit history remains intact, so it remains transparent for anyone why the redirect was created and what was the previous contents - I hate seeing good faith contributions (like AugPi's) being destroyed and the statistics of contributing editors being weakened by avoidable deletions - it's like a slap in the face of constructive editors. Also, if better sources would be found in the future or previous contents turn out to be useful to be incorporated into other articles, it is easy to extract them from the history, whereas contents deleted in AfDs is typically lost forever (and thus effectively wasted energy), as only admins can still see it and almost noone would ask for undeletion of an article deleted in a prior AfD discussion.
 * --Matthiaspaul (talk) 17:54, 13 May 2017 (UTC)


 * Redirect to Venn diagram. Some of the content can be merged into the §Related concepts part of that page. XOR&#39;easter (talk) 16:08, 15 May 2017 (UTC)


 * The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review). No further edits should be made to this page.