From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/6200 Path: news.gmane.org!not-for-mail From: "Eduardo J. Dubuc" Newsgroups: gmane.science.mathematics.categories Subject: Re: are fibrations evil? Date: Mon, 20 Sep 2010 13:59:01 -0300 Message-ID: References: Reply-To: "Eduardo J. Dubuc" NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable X-Trace: dough.gmane.org 1285118320 29531 80.91.229.12 (22 Sep 2010 01:18:40 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Wed, 22 Sep 2010 01:18:40 +0000 (UTC) Cc: John Baez , categories To: =?ISO-8859-1?Q?Andr=E9?= Original-X-From: majordomo@mlist.mta.ca Wed Sep 22 03:18:39 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 1OyDyn-00058a-BN for gsmc-categories@m.gmane.org; Wed, 22 Sep 2010 03:18:37 +0200 Original-Received: from mlist.mta.ca ([138.73.1.63]:46214) by smtpx.mta.ca with esmtp (Exim 4.71) (envelope-from ) id 1OyDxu-0006Qt-8A; Tue, 21 Sep 2010 22:17:42 -0300 Original-Received: from majordomo by mlist.mta.ca with local (Exim 4.71) (envelope-from ) id 1OyDxq-00049A-VG for categories-list@mlist.mta.ca; Tue, 21 Sep 2010 22:17:39 -0300 In-Reply-To: Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:6200 Archived-At: I completely agree with Andre. I add: Furthermore, the introduction of new terminology (specially if this=20 terminology refers directly to a meaning in everyday life) with no real=20 need and/or to change established terminology, is an habit that harm the=20 credibility of any school of research. In the present case we are discussing a particular single word "x" to=20 replace the compound "not invariant under equivalence". This seems=20 justified by its frequent use, but its frequent use is due precisely=20 because we are discussing its use !!!. In the practice of category theory or mathematics, its use is not=20 frequent enough to justify the introduction of new (simpler)=20 terminology. What happens with readers which see "x" and do not belong=20 to our group ?. Well, most will be upset , and specially if "x is evil" (ja !). Joyal wrote: > Dear John, >=20 > 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. >=20 > Best, > Andr=E9=20 >=20 [For admin and other information see: http://www.mta.ca/~cat-dist/ ]