From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/6106 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 10:46:49 -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 1283646035 18515 80.91.229.12 (5 Sep 2010 00:20:35 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Sun, 5 Sep 2010 00:20:35 +0000 (UTC) Cc: categories To: David Leduc Original-X-From: majordomo@mlist.mta.ca Sun Sep 05 02:20:31 2010 Return-path: Envelope-to: gsmc-categories@m.gmane.org Original-Received: from smtpy.mta.ca ([138.73.1.139]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Os2yF-0001s3-Au for gsmc-categories@m.gmane.org; Sun, 05 Sep 2010 02:20:31 +0200 Original-Received: from mlist.mta.ca ([138.73.1.63]:43628) by smtpy.mta.ca with esmtp (Exim 4.71) (envelope-from ) id 1Os2wp-0000DH-GV; Sat, 04 Sep 2010 21:19:03 -0300 Original-Received: from majordomo by mlist.mta.ca with local (Exim 4.71) (envelope-from ) id 1Os2wm-0006co-P2 for categories-list@mlist.mta.ca; Sat, 04 Sep 2010 21:19:00 -0300 In-Reply-To: Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:6106 Archived-At: On Sat, 4 Sep 2010, David Leduc wrote: > Are the notions of dual category and dual object related? > If not, are there any good reasons to use the word "dual" for both notions? > > Of course they're related. Under a categorical duality, the object in one category that corresponds to it in the other is the dual object. E.g. under the duality between sets and complete atomic boolean algebras, the object dual to to the set S is 2^S and the object dual to a CABA B is the set of atoms of B. [For admin and other information see: http://www.mta.ca/~cat-dist/ ]