From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/1849 Path: news.gmane.org!not-for-mail From: Dusko Pavlovic Newsgroups: gmane.science.mathematics.categories Subject: Re: Inevitability of ordering products Date: Mon, 12 Feb 2001 20:54:36 -0800 Message-ID: <3A88BE0C.C3CA8E04@kestrel.edu> References: <200102122027.PAA28404@cogito.math.uqam.ca> NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 X-Trace: ger.gmane.org 1241018150 800 80.91.229.2 (29 Apr 2009 15:15:50 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 29 Apr 2009 15:15:50 +0000 (UTC) To: categories@mta.ca Original-X-From: rrosebru@mta.ca Tue Feb 13 21:22:21 2001 -0400 Return-Path: Original-Received: (from Majordom@localhost) by mailserv.mta.ca (8.11.1/8.11.1) id f1E0nfO16599 for categories-list; Tue, 13 Feb 2001 20:49:41 -0400 (AST) X-Authentication-Warning: mailserv.mta.ca: Majordom set sender to cat-dist@mta.ca using -f X-Mailer: Mozilla 4.72 [en] (X11; U; SunOS 5.5.1 sun4u) X-Accept-Language: en Original-Sender: cat-dist@mta.ca Precedence: bulk X-Keywords: X-UID: 31 Original-Lines: 27 Xref: news.gmane.org gmane.science.mathematics.categories:1849 Archived-At: Eduardo Dubuc wrote: > what sense has the concept of unlabeled graph ? > > try to put an unlabeled graph inside a computer ? you mean unordered? i would implement it as an ordered graph, with an additional involutive map on the edges, ie Edges <--inv-- Edges ==dom,cod==> Nodes dom.inv = cod inv.inv = id --- which, in a way, confirms that > well, unlabeled graph has to be a quotient by an equivalent relation ... isn't the "ordering" of the components of a product AxB (by the names, colors A and B), in a similar way, "factored out" by the canonical isomorphism with BxA? isn't coherence theory the way we can always factor out such arbitrary annotations on objects? (SORRY i am posting too much.) -- dusko