From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/5974 Path: news.gmane.org!not-for-mail From: Vaughan Pratt Newsgroups: gmane.science.mathematics.categories Subject: Re: non-Hausdoff topology Date: Wed, 07 Jul 2010 20:19:12 -0700 Message-ID: Reply-To: Vaughan Pratt NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Trace: dough.gmane.org 1278683716 15342 80.91.229.12 (9 Jul 2010 13:55:16 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Fri, 9 Jul 2010 13:55:16 +0000 (UTC) To: categories list Original-X-From: categories@mta.ca Fri Jul 09 15:55:14 2010 Return-path: Envelope-to: gsmc-categories@m.gmane.org Original-Received: from mailserv.mta.ca ([138.73.1.1]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1OXE2p-00073h-Cf for gsmc-categories@m.gmane.org; Fri, 09 Jul 2010 15:55:11 +0200 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1OXDZ0-0004AE-TN for categories-list@mta.ca; Fri, 09 Jul 2010 10:24:22 -0300 Original-Sender: categories@mta.ca Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:5974 Archived-At: On 7/7/2010 10:28 AM, Michael Barr wrote: > Not just in CS, but also central to algebraic geometry: the Zariski > topology is almost never hausdorff. But when topology is taught to > undergraduates, it is usually for the purposes of analysis and I don't > know if we could this point across. My understanding of Paul's complaint was with the passage not so much from T2 to T0 but from T1 to T0, needed for the Scott topology. The Zariski topology is always T1. Vaughan Pratt [For admin and other information see: http://www.mta.ca/~cat-dist/ ]