Talk:Transitive Set Contained in Von Neumann Hierarchy Level

Simplification
This proof is just a tad longer than I would really like, but I'm not seeing any obvious ways to simplify or refactor it. Anyone else see anything? --Dfeuer (talk) 07:39, 28 December 2012 (UTC)

Expansion
NLab page on axiom of foundation claims that in fact each transitive set equals a level of the Von Neumann hierarchy. We should try to prove that. --Dfeuer (talk) 07:39, 28 December 2012 (UTC)


 * What's your connection with nlab? I'm dubious about using links to it as source citations. Its style is too discursive and it is difficult to get any sense of what any of the pages are actually about. (IOW: I can't make the slightest head-or-tail of whatever any of it is trying to communicate. Is it trying to communicate or just be intimidatingly high-intellect?) I fear that sending users to such a page will only serve to confuse. --prime mover (talk) 09:20, 28 December 2012 (UTC)


 * I have no connection to it. I don't even know exactly what it is. It seems to have some useful ideas in it that could be used to build things, but many pieces are missing. --Dfeuer (talk) 09:58, 28 December 2012 (UTC)


 * Feel free to get ideas from it, but unless someone provides a strong argument for its inclusion, the final paragraph of Help:Sources stands for now. --prime mover (talk) 10:01, 28 December 2012 (UTC)


 * Isn't that ... ah ... potentially plagiarism? Just because you don't like a source doesn't mean it wasn't one. --Dfeuer (talk) 10:04, 28 December 2012 (UTC)


 * Who knows? They don't publish their copyright policy on their pages, and in fact I can find no indication anywhere what that policy is. If you look at the other sites which we have use as source, they all have strict instructions as to how their material is to be referenced.


 * If it's a concern, then I recommend you don't use it as a source at all. That would in fact be my fervent advice to anyone though, under any circumstances. Having said that, unless you copy and paste the contents of their pages directly into ProofWiki pages, and leave it in the same style without even trying to rewrite it so as to contain a vestige of communicatory ability, it is unlikely that they can pin us down. But if you were to do that, it would not take long before someone were to either rewrite such a page or just delete it as twaddle. --prime mover (talk) 10:21, 28 December 2012 (UTC)

In my eyes the lack of a copyright statement emphasizes the purpose of the site: to share thoughts with others and one's later self to help facilitate research (thus, PMs dichotomy was a false one as the correct answer is "Both."). Their purpose is ultimately a bit similar to ours, but they don't see the need to document all approaches (only the very general, "modern, higher categorical point of view"). There is no pretension of any kind; I think the material may be borrowed, even without mention, and that this is the way it is intended to be. --Lord_Farin (talk) 11:01, 28 December 2012 (UTC)


 * On-topic, I'd like to add that we should indeed pursue such a thing. --Lord_Farin (talk) 11:05, 28 December 2012 (UTC)


 * Their terms of use. They don't say much, but citation is expected in both directions. --Dfeuer (talk) 15:55, 28 December 2012 (UTC)