From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/6522 Path: news.gmane.org!not-for-mail From: Tom Prince Newsgroups: gmane.science.mathematics.categories Subject: Re: source, sinks, and ? Date: Fri, 04 Feb 2011 13:48:44 -0500 Message-ID: References: Reply-To: Tom Prince NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: dough.gmane.org 1296868385 32260 80.91.229.12 (5 Feb 2011 01:13:05 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Sat, 5 Feb 2011 01:13:05 +0000 (UTC) To: Michael Shulman , categories Original-X-From: majordomo@mlist.mta.ca Sat Feb 05 02:12:59 2011 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 1PlWhu-0001Fd-Uc for gsmc-categories@m.gmane.org; Sat, 05 Feb 2011 02:12:59 +0100 Original-Received: from mlist.mta.ca ([138.73.1.63]:52699) by smtpx.mta.ca with esmtp (Exim 4.71) (envelope-from ) id 1PlWhn-0000sJ-3K; Fri, 04 Feb 2011 21:12:51 -0400 Original-Received: from majordomo by mlist.mta.ca with local (Exim 4.71) (envelope-from ) id 1PlWhc-0003Hz-Os for categories-list@mlist.mta.ca; Fri, 04 Feb 2011 21:12:41 -0400 In-Reply-To: Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:6522 Archived-At: On 2011-01-02, Michael Shulman wrote: > A family of morphisms { x_i --> y }_{i \in I} in some category, all > with the same codomain, is called a "sink" or a "cocone". A family { > x --> y_j }_{j \in J} all with the same domain is called a "source" or > a "cone". Is there a name for a family of the form { x_i --> y_j }_{i > \in I, j \in J} ? A cylinder? Or a frustrum (since I \neq J)? > > Mike A join? Tom [For admin and other information see: http://www.mta.ca/~cat-dist/ ]