From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/6063 Path: news.gmane.org!not-for-mail From: David Leduc Newsgroups: gmane.science.mathematics.categories Subject: Generalizing Comma Categories Date: Sat, 21 Aug 2010 01:46:10 +0000 Message-ID: Reply-To: David Leduc NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 X-Trace: dough.gmane.org 1282487279 31657 80.91.229.12 (22 Aug 2010 14:27:59 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Sun, 22 Aug 2010 14:27:59 +0000 (UTC) To: categories@mta.ca Original-X-From: majordomo@mlist.mta.ca Sun Aug 22 16:27:58 2010 Return-path: Envelope-to: gsmc-categories@m.gmane.org Original-Received: from smtpx.mta.ca ([138.73.1.138]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1OnBWf-0006k2-RE for gsmc-categories@m.gmane.org; Sun, 22 Aug 2010 16:27:58 +0200 Original-Received: from mlist.mta.ca ([138.73.1.63]:40456) by smtpx.mta.ca with esmtp (Exim 4.71) (envelope-from ) id 1OnBVA-0007mv-2L; Sun, 22 Aug 2010 11:26:24 -0300 Original-Received: from majordomo by mlist.mta.ca with local (Exim 4.71) (envelope-from ) id 1OnBV5-0000A1-Sf for categories-list@mlist.mta.ca; Sun, 22 Aug 2010 11:26:19 -0300 Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:6063 Archived-At: Hi, Thank you for all the replies to my previous questions. It is very helpful. Now, I have another (trivial) question. If I have two constant functors Delta_X and Delta_Y that respectively returns X and Y in C, then their comma category is the discrete category C(X,Y). How do comma categories generalize to bicategories? When C is a 2-category, I would like the "comma category" of the "functors"(?) Delta_X and Delta_Y be the (not necessarily discrete) category C(X,Y). [For admin and other information see: http://www.mta.ca/~cat-dist/ ]