From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/3648 Path: news.gmane.org!not-for-mail From: John Baez Newsgroups: gmane.science.mathematics.categories Subject: terminology: dagger and involution Date: Thu, 1 Mar 2007 19:34:24 -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 1241019433 9624 80.91.229.2 (29 Apr 2009 15:37:13 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 29 Apr 2009 15:37:13 +0000 (UTC) To: categories Original-X-From: rrosebru@mta.ca Fri Mar 2 17:27:49 2007 -0400 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Fri, 02 Mar 2007 17:27:49 -0400 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1HNFBy-0003UD-3T for categories-list@mta.ca; Fri, 02 Mar 2007 17:21:30 -0400 Content-Disposition: inline Original-Sender: cat-dist@mta.ca Precedence: bulk X-Keywords: X-UID: 2 Original-Lines: 34 Xref: news.gmane.org gmane.science.mathematics.categories:3648 Archived-At: On Thu, Mar 01, 2007 at 09:21:55AM +0000, V. Schmitt wrote: > John Baez wrote: > >by now there's enough literature using the term "dagger-categories" > >that the genie is out of the bottle. > Dear John, just my view: this is not a good argument. It's not an argument - I'm just reporting on what I see. I don't really like the term "dagger-categories", and I gently tried to get people to stop using it, but it didn't work. They're already comfortable with it. > I do not know about these dagger categories though > i read about the compact closed ones. > So may be I miss the point but, if this is the case, why > introducing a new terminology if the concepts are not? > That just creates confusion. I hope this is clear: "dagger-categories" are completely different from "compact closed categories". We need *some* term for them; we're just arguing about whether to call them "star-categories", "dagger-categories", or "categories with involution". I like "star-categories", because in analysis and quantum topology the special case of "C*-categories" is very important. But, I doubt we'll reach any sort of agreement! Best, jb