From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/1139 Path: news.gmane.org!not-for-mail From: Michael Barr Newsgroups: gmane.science.mathematics.categories Subject: Question on subobject classifiers Date: Sat, 12 Jun 1999 09:04:33 -0400 (EDT) Message-ID: NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Trace: ger.gmane.org 1241017593 29675 80.91.229.2 (29 Apr 2009 15:06:33 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 29 Apr 2009 15:06:33 +0000 (UTC) To: Categories list Original-X-From: cat-dist Sat Jun 12 20:10:21 1999 Original-Received: (from Majordom@localhost) by mailserv.mta.ca (8.9.3/8.9.3) id TAA06947 for categories-list; Sat, 12 Jun 1999 19:05:13 -0300 (ADT) X-Authentication-Warning: triples.math.mcgill.ca: barr owned process doing -bs Original-Sender: cat-dist@mta.ca Precedence: bulk Original-Lines: 16 Xref: news.gmane.org gmane.science.mathematics.categories:1139 Archived-At: I am reviewing a paper whose main result sounds like it ought to be known. Is it and can anyone give me a citation? Let E be a cocomplete category with a small dense subcategory C (so every e of E is the colimit of C/e --> E). Then an object \Omega of E is a subobject classifier in E iff it represents the subobject functor restricted to C. ------------------------------------------------------------------- If a society puts up with bad plumbers because plumbing is such a low calling, and if it puts up with bad philosophers because philosophy is such a high calling---then neither its pipes nor its theories will hold water. --- Slight paraphrase of former HEW secretary John Gardner