From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/5837 Path: news.gmane.org!not-for-mail From: Toby Bartels Newsgroups: gmane.science.mathematics.categories Subject: Re: "injective" terminology Date: Sat, 22 May 2010 10:08:25 -0700 Message-ID: References: <4BF7FCB1.70303@bangor.ac.uk> Reply-To: Toby Bartels NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: dough.gmane.org 1274622255 3240 80.91.229.12 (23 May 2010 13:44:15 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Sun, 23 May 2010 13:44:15 +0000 (UTC) To: Timothy Porter Original-X-From: categories@mta.ca Sun May 23 15:44:11 2010 connect(): No such file or directory 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 1OGBTP-0005tn-7F for gsmc-categories@m.gmane.org; Sun, 23 May 2010 15:44:11 +0200 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1OGAyD-0001Wf-AS for categories-list@mta.ca; Sun, 23 May 2010 10:11:57 -0300 Content-Disposition: inline Original-Sender: categories@mta.ca Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:5837 Archived-At: Timothy Porter wrote: >I always thought that ind-object in the work of Grothendieck and the SGA >seminars was short for inductive object. The "ind-" in "ind-object" does stand for "inductive", which is dual to "projective" for the "pro-" in "pro-object", but an ind-object is not the same thing as an injective object (and also a pro-object is not the same thing as a projective object). http://ncatlab.org/nlab/show/ind-object http://ncatlab.org/nlab/show/injective+object http://ncatlab.org/nlab/show/pro-object http://ncatlab.org/nlab/show/projective+object --Toby [For admin and other information see: http://www.mta.ca/~cat-dist/ ]