From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/6331 Path: news.gmane.org!not-for-mail From: Marta Bunge Newsgroups: gmane.science.mathematics.categories Subject: Re: property_vs_structure Date: Thu, 21 Oct 2010 13:51:42 -0400 Message-ID: References: Reply-To: Marta Bunge 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 1287695821 13305 80.91.229.12 (21 Oct 2010 21:17:01 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Thu, 21 Oct 2010 21:17:01 +0000 (UTC) To: Original-X-From: majordomo@mlist.mta.ca Thu Oct 21 23:17:00 2010 Return-path: Envelope-to: gsmc-categories@m.gmane.org Original-Received: from smtpx.mta.ca ([138.73.1.114]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1P92VP-0000bM-I3 for gsmc-categories@m.gmane.org; Thu, 21 Oct 2010 23:16:59 +0200 Original-Received: from mlist.mta.ca ([138.73.1.63]:36514) by smtpx.mta.ca with esmtp (Exim 4.71) (envelope-from ) id 1P92Us-0006hz-9f; Thu, 21 Oct 2010 18:16:26 -0300 Original-Received: from majordomo by mlist.mta.ca with local (Exim 4.71) (envelope-from ) id 1P92Up-0002Wv-JP for categories-list@mlist.mta.ca; Thu, 21 Oct 2010 18:16:23 -0300 Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:6331 Archived-At: Dear George=2C Thank you for your comments and questions. =A0I will have to look closely i= nto the conditions of coverings in your sense to make sure that the off-my-= hat assertion that unramified maps are an example is indeed correct.=A0Also= =2C your remark about the path-lifting property being "categorically forced= " upon you in your work with Aurelio is particularly interesting to me as y= ou suggested. I will most certainly look into those two points.=A0 I am also familiar with the T-categories and lax algebras=2C so that the wo= rk of Clementino=2C Hoffman and yourself should be easy for me to understan= d. =A0I point out (in case you do not know this) that my paper "Coherent ex= tensions and relational algebras"=2C Trans. AMS 197 (1974) 355-390 introduc= es lax adjointness=2C =A0examines examples including the T-categories of Bu= rroni=2C and gives a new analysis of the example of topological spaces in t= his new light. =A0I mentioned this paper to Maria Manuel Clementino the fir= st time I heard her talk about this subject=2C as it was obviously relevant= .=A0 However=2C in view of my imminent trip to Buenos Aires=2C where I will spen= d most of November=2C I doubt that I will find the time this week to look i= nto all of that before I return.=A0 With best regards=2CMarta ************************************************ Marta Bunge Professor Emerita Dept of Mathematics and Statistics=20 McGill UniversityBurnside Hall=2C Office 1005 805 Sherbrooke St. West Montreal=2C QC=2C Canada H3A 2K6 Office: (514) 398-3810/3800 =A0 Home: (514) 935-3618 marta.bunge@mcgill.ca=20 http://www.math.mcgill.ca/~bunge/ ************************************************ [For admin and other information see: http://www.mta.ca/~cat-dist/ ]