From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/5113 Path: news.gmane.org!not-for-mail From: =?utf-8?q?Bj=C3=B6rn_Gohla?= Newsgroups: gmane.science.mathematics.categories Subject: Re: The Wikibook on Category Theory Date: Sun, 23 Aug 2009 21:11:28 +0100 Message-ID: Reply-To: =?utf-8?q?Bj=C3=B6rn_Gohla?= NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Trace: ger.gmane.org 1251561770 3502 80.91.229.12 (29 Aug 2009 16:02:50 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 29 Aug 2009 16:02:50 +0000 (UTC) To: categories Original-X-From: categories@mta.ca Sat Aug 29 18:02:43 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 1MhQO3-0007Vc-7v for gsmc-categories@m.gmane.org; Sat, 29 Aug 2009 18:02:43 +0200 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1MhPtM-0005Bq-6S for categories-list@mta.ca; Sat, 29 Aug 2009 12:31:00 -0300 Content-Disposition: inline Original-Sender: categories@mta.ca Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:5113 Archived-At: On Thursday August 20 2009, John Baez wrote: > Andrew Salch wrote: > > I often find that I need to know if certain kinds of limits, or colimits, > > > or injective envelopes, etc. etc. etc. exist in a particular category, > > and having some central database to look at (which would hopefully tell > > me what I need to know as well as cite whatever paper the result was > > proved in) would be a lot quicker than having to either search the > > literature for such a result or try to re-prove the result myself. Does > > anyone know if there have been any attempts to compile such a database? > > I don't know of any such attempts. I've always wanted such a database! = An > obvious place to create it is on the nLab. I just started one: > > http://ncatlab.org/nlab/show/database+of+categories > > but it will only become interesting after a while. > > If everyone here contributes an entry or two today, it will be interesting > by tomorrow! [...] well, ultimately it would be interesting to have a categorical analogue to= =20 =C2=ABcounterexamples in topology=C2=BB.=20 =2D- regards, bj=C3=B6rn [For admin and other information see: http://www.mta.ca/~cat-dist/ ]