Talk:Family of sets

who might need it? Tosha 20:23, 14 Jun 2004 (UTC)

Merge?
The obvious merge target is hypergraph, which set system currently points to. Can this article be differentiated from that one enough to stand alone, or should they be merged (as Oleg has already hinted)? —David Eppstein 06:33, 26 July 2007 (UTC)

The terms "hypergraph" and "set system" are used in combinatorics, while the term "family of sets" is used in abstract set theory. They're not quite equivalent; a hypergraph should be a collection of subsets of a fixed set, and (at least according to our article) should also be nonempty. Even if they were precisely equivalent, their usages differ since they appear in different branches of mathematics. So I believe that the articles should stay separate, while still referring to one another. —Toby Bartels 22:00, 26 July 2007 (UTC)

--Abdull (talk) 08:52, 30 July 2008 (UTC)
 * In set theory and related branches of mathematics, a collection F of subsets of a given set S is called a family of subsets of S, or a family of sets over S. 
 * Collection as in set?


 * I also felt confused about the word "collection". However, the article shows that more than just "sets" are intended; see the "large family" clause. I don't know if "collection" is used as synonymous to "class", or as a more informal notion, or in some other sense.
 * Moreover, I'm unused to the term "family" having this precise meaning in set theory. Therefore, I'd like to see one or a couple of references. I also think the article would benefit from some such reference. Finally, I'd like to know if the described terminology - in particular, "large family" - is well established terminology in the area, or just employed by one author, or something in between.
 * Thanks in advance, JoergenB (talk) 22:10, 8 November 2008 (UTC)

Simple Version Needed
This is functionally incomprehensible to anyone without a grounding in number theory. Can some attempt be made to explain this in non-jargon terms? 99.111.150.112 (talk) 07:03, 7 December 2019 (UTC)
 * It's set theory, not number theory. And it's perhaps a little cryptic in its current form, but Ptolemy I Soter also comes to mind as relevant. —David Eppstein (talk) 07:19, 7 December 2019 (UTC)

Family means function
In the mathematics literature (see e.g. Herstein), far more often the term family is a synonym for function, so a family of sets is a set-valued function. Boute (talk) 10:05, 12 February 2021 (UTC)

mistake?
I think there is a mistake in the table: a Dynkin system is not closed under intersection, is it? 62.240.134.129 (talk) 09:06, 2 October 2021 (UTC)


 * I edited the corresponding page (Template:Families of sets), so the table should be correct now. Jakeskat (talk) 18:29, 30 June 2022 (UTC)