Talk:Hereditarily finite set

I see a square on this page where there should be a union symbol (a bit like a big plain capital U). Do other people get the same thing, or is it my font? If it is broke, can someone fix it who knows how? Onebyone 10:22, 2 Oct 2003 (UTC)
 * It's the HTML entity &cup; a bit larger because TeX was stuffing up before. I think I'll rewrite it in TeX, but it probably won't render good at the moment. Dysprosia 10:27, 2 Oct 2003 (UTC)

Removed from Votes for Deletion:


 * Hereditarily finite set. Strange maths stuff. Makes no sense. Angela 00:52, Oct 2, 2003 (UTC)
 * Probably a weird dream of an aspiring mathematician. --Menchi 01:16, 2 Oct 2003 (UTC)
 * Googling for "hereditarily finite" finds 650 hits, mostly to mathematical papers. I think it's a valid concept. However, the article could do with a lot of expansion, as at the moment it does not give me the first clue what "hereditarily finite" means. -- Karada 08:33, 2 Oct 2003 (UTC)
 * Did a bit of googling - decoded. Dysprosia 09:06, 2 Oct 2003 (UTC)
 * It's important in maths. If I get round to it, I'll write some content to explain why, but in any case keep. -- Onebyone 10:24, 2 Oct 2003 (UTC)

Certainly it's a valid concept, but the article could elaborate. Efficient definitions are usually not the most instructive ones. A hereditarily finite set is finite, and all of its members are themselves hereditarily finite. A finite set some of whose members, or the members of whose members, etc., are sets that are not finite, is finite but not hereditarily finite. Michael Hardy 04:59, 17 Oct 2003 (UTC)


 * Why don't you add that to, or change the article? Dysprosia 14:57, 17 Oct 2003 (UTC)
 * Done Onebyone 15:15, 17 Oct 2003 (UTC)