From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/5233 Path: news.gmane.org!not-for-mail From: "George Janelidze" Newsgroups: gmane.science.mathematics.categories Subject: Re: Question on exact sequence Date: Wed, 11 Nov 2009 18:36:25 +0200 Message-ID: <020701ca62ed$1faf6500$0b00000a@C3> Reply-To: "George Janelidze" NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain;charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1257993900 29097 80.91.229.12 (12 Nov 2009 02:45:00 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 12 Nov 2009 02:45:00 +0000 (UTC) To: , Original-X-From: categories@mta.ca Thu Nov 12 03:44:53 2009 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 4.50) id 1N8Pg3-0001aT-7C for gsmc-categories@m.gmane.org; Thu, 12 Nov 2009 03:44:51 +0100 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1N8PF8-0007RS-84 for categories-list@mta.ca; Wed, 11 Nov 2009 22:17:02 -0400 Original-Sender: categories@mta.ca Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:5233 Archived-At: Dear All, As I understand, my previous message was written after Marco's and Steve's messages, although I saw them only afterwards. Unfortunately I don't have time now, but putting these things together would be very interesting. Specifically: 1. Marco vs Steve: Marco's result contains what Michael is mentioning (=Exercise VIII.4.6 in Mac Lane's book) plus Snake Lemma, but does it contain what Steve describes as Enrico's result? 2. Marco vs George: And do you, Marco, have a canonical connecting morphism? 3. Steve vs George: Do you, Steve - hence Enrico - have a canonical connecting morphism depending on what you call z : A ---> C' in your (Steve) message? George [For admin and other information see: http://www.mta.ca/~cat-dist/ ]