From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/6112 Path: news.gmane.org!not-for-mail From: Michael Barr Newsgroups: gmane.science.mathematics.categories Subject: Re: Dual category and dual object Date: Sat, 4 Sep 2010 20:47:20 -0400 (EDT) Message-ID: References: Reply-To: Michael Barr NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Trace: dough.gmane.org 1283701346 31461 80.91.229.12 (5 Sep 2010 15:42:26 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Sun, 5 Sep 2010 15:42:26 +0000 (UTC) Cc: categories , David Leduc To: Toby Bartels Original-X-From: majordomo@mlist.mta.ca Sun Sep 05 17:42:24 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 1OsHMH-00048c-2G for gsmc-categories@m.gmane.org; Sun, 05 Sep 2010 17:42:17 +0200 Original-Received: from mlist.mta.ca ([138.73.1.63]:51507) by smtpx.mta.ca with esmtp (Exim 4.71) (envelope-from ) id 1OsHL6-0007lM-HC; Sun, 05 Sep 2010 12:41:04 -0300 Original-Received: from majordomo by mlist.mta.ca with local (Exim 4.71) (envelope-from ) id 1OsHL4-0005NL-2t for categories-list@mlist.mta.ca; Sun, 05 Sep 2010 12:41:02 -0300 In-Reply-To: Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:6112 Archived-At: On Sat, 4 Sep 2010, Toby Bartels wrote: > David Leduc wrote: > >> Are the notions of dual category and dual object related? >....................................................... > > On the other hand, we can say "opposite category" instead of "dual category", > especially since we denote the dual category of C by C^{op}. > So you would say that complete atomic boolean algebras is just Set^{op}? Well I wouldn't. They are, of course, equivalent, but not the same. [For admin and other information see: http://www.mta.ca/~cat-dist/ ]