From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/5098 Path: news.gmane.org!not-for-mail From: Andrew Salch Newsgroups: gmane.science.mathematics.categories Subject: Re: The Wikibook on Category Theory Date: Wed, 19 Aug 2009 12:42:46 -0400 (EDT) Message-ID: Reply-To: Andrew Salch NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE X-Trace: ger.gmane.org 1250791160 3772 80.91.229.12 (20 Aug 2009 17:59:20 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 20 Aug 2009 17:59:20 +0000 (UTC) To: categories@mta.ca Original-X-From: categories@mta.ca Thu Aug 20 19:59:04 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 1MeBud-0002kr-Nx for gsmc-categories@m.gmane.org; Thu, 20 Aug 2009 19:58:59 +0200 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1MeBHO-0001J9-Tg for categories-list@mta.ca; Thu, 20 Aug 2009 14:18:26 -0300 Original-Sender: categories@mta.ca Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:5098 Archived-At: I have found nLab very helpful as well, for when I need to look up a=20 definition of some higher-categorical construction and I don't have a book= =20 or paper on hand to refer to. I have thought many times, though, that it=20 would be great if there were some Web-accessible database of categories=20 which are commonly encountered in mathematics, and their properties; I=20 often find that I need to know if certain kinds of limits, or colimits, or= =20 injective envelopes, etc. etc. etc. exist in a particular category, and=20 having some central database to look at (which would hopefully tell me=20 what I need to know as well as cite whatever paper the result was proved=20 in) would be a lot quicker than having to either search the literature for= =20 such a result or try to re-prove the result myself. Does anyone know if=20 there have been any attempts to compile such a database? Thanks, Andrew S. On Tue, 18 Aug 2009, Michael Shulman wrote: > I love the nLab too, but I'm not sure that "merging" is the right > word; probably the two are serving slightly different purposes. The > overall nLab is not really organized like a textbook or designed to be > read linearly; writing a textbook requires additional thought. But > there is certainly no reason why the two can't share material and link > to each other as appropriate. And/or one could choose to write a > textbook as a section of the nLab rather than on Wikibooks (if, for > instance, one preferred its offerings in the way of mathematical > typesetting). > > Mike > [For admin and other information see: http://www.mta.ca/~cat-dist/ ]