From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/7427 Path: news.gmane.org!not-for-mail From: Ross Street Newsgroups: gmane.science.mathematics.categories Subject: Re: Preprint: A direct proof that the category of 3-computads is not cartesian closed Date: Wed, 5 Sep 2012 12:26:51 +1000 Message-ID: References: Reply-To: Ross Street NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable X-Trace: ger.gmane.org 1346872013 2336 80.91.229.3 (5 Sep 2012 19:06:53 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 5 Sep 2012 19:06:53 +0000 (UTC) Cc: Categories list To: Eugenia Cheng Original-X-From: majordomo@mlist.mta.ca Wed Sep 05 21:06:55 2012 Return-path: Envelope-to: gsmc-categories@m.gmane.org Original-Received: from smtpy.mta.ca ([138.73.1.128]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1T9Kw2-0008If-PD for gsmc-categories@m.gmane.org; Wed, 05 Sep 2012 21:06:46 +0200 Original-Received: from mlist.mta.ca ([138.73.1.63]:42160) by smtpy.mta.ca with esmtp (Exim 4.77) (envelope-from ) id 1T9Kuv-0004z1-N0; Wed, 05 Sep 2012 16:05:37 -0300 Original-Received: from majordomo by mlist.mta.ca with local (Exim 4.71) (envelope-from ) id 1T9KvA-0006CA-MG for categories-list@mlist.mta.ca; Wed, 05 Sep 2012 16:05:52 -0300 In-Reply-To: Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:7427 Archived-At: Dear Eugenia On 04/09/2012, at 10:48 AM, Eugenia Cheng wrote: > I've just posted a note on the arXiv, giving a short proof by = counterexample that the category of 3-computads is not cartesian closed. >=20 > http://arxiv.org/abs/1209.0414 >=20 > This result was first proved by Makkai and Zawadowski: >=20 > 3-computads do not form a presheaf category. Journal of Pure and = Applied Algebra, 212(11):2543--3546, 2008. A bit of shock hit me to see that the Makkai and Zawadowski paper was = over 1000 pages! But I see from MathSci that the correct page numbers are 2543=962546.=20 I look forward to reading your approach. Regards, Ross= [For admin and other information see: http://www.mta.ca/~cat-dist/ ]