From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/6444 Path: news.gmane.org!not-for-mail From: JeanBenabou Newsgroups: gmane.science.mathematics.categories Subject: Re: Re: source, sinks, and ? Date: Tue, 4 Jan 2011 09:41:46 +0100 Message-ID: References: Reply-To: JeanBenabou NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 (Apple Message framework v753.1) Content-Type: text/plain; charset=ISO-8859-1; delsp=yes; format=flowed Content-Transfer-Encoding: quoted-printable X-Trace: dough.gmane.org 1294150198 12602 80.91.229.12 (4 Jan 2011 14:09:58 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Tue, 4 Jan 2011 14:09:58 +0000 (UTC) To: Albert Burroni , Categories Original-X-From: majordomo@mlist.mta.ca Tue Jan 04 15:09:52 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 1Pa7a9-0006vG-Nf for gsmc-categories@m.gmane.org; Tue, 04 Jan 2011 15:09:49 +0100 Original-Received: from mlist.mta.ca ([138.73.1.63]:38996) by smtpx.mta.ca with esmtp (Exim 4.71) (envelope-from ) id 1Pa7Zv-000359-PO; Tue, 04 Jan 2011 10:09:35 -0400 Original-Received: from majordomo by mlist.mta.ca with local (Exim 4.71) (envelope-from ) id 1Pa7Zm-000695-Fb for categories-list@mlist.mta.ca; Tue, 04 Jan 2011 10:09:26 -0400 Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:6444 Archived-At: Dear Albert, I "half agree" with you. The term "matrix" has been used by by Freyd-=20 Scedrov in their allegories, by myself in my paper on distributors, =20 and probably by many other persons. However in both cases the situation was such that one could define =20 the "product" of two matrixes and get an allegory or more generally a =20= bi-category, and I suggest it should be restricted to such cases. In =20 the general situation where the product is not defined, I suggest the =20= word "array" (with entries in C, if we want to specify C) Bonnne Ann=E9e, Jean Le 3 janv. 11 =E0 23:40, burroni@math.jussieu.fr a =E9crit : > Dear Mike, > > In fact, we can call it a matrix (of (I x J)- type) with =20 > coefficients in the category. When the category is a category of =20 > modules, we have that way a natural generalization of classical =20 > matrices. > > Cheers, > Albert > [For admin and other information see: http://www.mta.ca/~cat-dist/ ]