From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/3642 Path: news.gmane.org!not-for-mail From: John Baez Newsgroups: gmane.science.mathematics.categories Subject: terminology: dagger and involution Date: Mon, 26 Feb 2007 08:22:21 -0800 Message-ID: NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1241019429 9607 80.91.229.2 (29 Apr 2009 15:37:09 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 29 Apr 2009 15:37:09 +0000 (UTC) To: categories Original-X-From: rrosebru@mta.ca Tue Feb 27 21:54:14 2007 -0400 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 27 Feb 2007 21:54:14 -0400 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1HMDrk-0001vq-Ll for categories-list@mta.ca; Tue, 27 Feb 2007 21:44:24 -0400 Content-Disposition: inline Original-Sender: cat-dist@mta.ca Precedence: bulk X-Keywords: X-UID: 36 Original-Lines: 26 Xref: news.gmane.org gmane.science.mathematics.categories:3642 Archived-At: Marco wrote: >what you are calling a "dagger-category", i.e. > > a category equipped with a contravariant involutive > endofunctor, which is the identity on objects, > >has been called "a category with involution", at least from Burgin >1969 to Lambek 2001. "Involutive category" has also been used, if >less. > >I think it would be better to come back to the old term, which is >meaningful, translatable, and old. There's also a body of work, mainly from mathematical physics, that calls these categories "star-categories". But, by now there's enough literature using the term "dagger-categories" that the genie is out of the bottle. Best, jb