From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/5976 Path: news.gmane.org!not-for-mail From: Erik Palmgren Newsgroups: gmane.science.mathematics.categories Subject: Re: non-Hausdoff topology Date: Thu, 8 Jul 2010 13:54:14 +0200 (CEST) Message-ID: References: Reply-To: Erik Palmgren NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: TEXT/PLAIN; format=flowed; charset=US-ASCII X-Trace: dough.gmane.org 1278683903 15987 80.91.229.12 (9 Jul 2010 13:58:23 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Fri, 9 Jul 2010 13:58:23 +0000 (UTC) Cc: categories@mta.ca To: Paul Taylor Original-X-From: categories@mta.ca Fri Jul 09 15:58:21 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 1OXE5r-0000x6-VE for gsmc-categories@m.gmane.org; Fri, 09 Jul 2010 15:58:20 +0200 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1OXDa2-0004Dc-DB for categories-list@mta.ca; Fri, 09 Jul 2010 10:25:26 -0300 In-Reply-To: Original-Sender: categories@mta.ca Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:5976 Archived-At: So-called "digital" topologies are simple and illustrative examples of non-Hausdorff topologies suitable for undergraduate classes. These are finite combinatorial topologies that are used to define connectivity of images on a computer screen. See for instance Chapter 9 of these lecture notes of Christer Kiselman "Digital Geometry and Mathematical Morphology" http://www.math.uu.se/~kiselman/dgmm2004.pdf There is even a Wikipedia article http://en.wikipedia.org/wiki/Digital_topology [For admin and other information see: http://www.mta.ca/~cat-dist/ ]