From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/6191 Path: news.gmane.org!not-for-mail From: =?iso-8859-1?Q?Joyal=2C_Andr=E9?= Newsgroups: gmane.science.mathematics.categories Subject: Re: are fibrations evil? Date: Sat, 18 Sep 2010 09:50:44 -0400 Message-ID: References: Reply-To: =?iso-8859-1?Q?Joyal=2C_Andr=E9?= NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable X-Trace: dough.gmane.org 1284906290 27821 80.91.229.12 (19 Sep 2010 14:24:50 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Sun, 19 Sep 2010 14:24:50 +0000 (UTC) To: "John Baez" , "categories" Original-X-From: majordomo@mlist.mta.ca Sun Sep 19 16:24:49 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 1OxKoy-0003wW-Ih for gsmc-categories@m.gmane.org; Sun, 19 Sep 2010 16:24:48 +0200 Original-Received: from mlist.mta.ca ([138.73.1.63]:49286) by smtpx.mta.ca with esmtp (Exim 4.71) (envelope-from ) id 1OxKoE-0003Ey-0R; Sun, 19 Sep 2010 11:24:02 -0300 Original-Received: from majordomo by mlist.mta.ca with local (Exim 4.71) (envelope-from ) id 1OxKoA-0004wT-Jd for categories-list@mlist.mta.ca; Sun, 19 Sep 2010 11:23:58 -0300 Content-class: urn:content-classes:message Thread-Index: ActW0LukQZE+tlniT+iPN5TMKFcO4gAZpKfN Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:6191 Archived-At: Dear John, A property is "evil" in your sense if it is not invariant under equivalences. Invariance under equivalence is a well established mathematical notion. I prefer to say that something is not invariant under equivalence than to say that it is "evil". There is no need to introduce a new terminology. Best, Andr=E9=20 =20 [For admin and other information see: http://www.mta.ca/~cat-dist/ ]