From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/6294 Path: news.gmane.org!not-for-mail From: "Fred E.J. Linton" Newsgroups: gmane.science.mathematics.categories Subject: Re: potential names Date: Tue, 05 Oct 2010 18:18:17 -0400 Message-ID: Reply-To: "Fred E.J. Linton" NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Trace: dough.gmane.org 1286367684 4809 80.91.229.12 (6 Oct 2010 12:21:24 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Wed, 6 Oct 2010 12:21:24 +0000 (UTC) Cc: Vaughan Pratt To: Categories list Original-X-From: majordomo@mlist.mta.ca Wed Oct 06 14:21:21 2010 Return-path: Envelope-to: gsmc-categories@m.gmane.org Original-Received: from smtpx.mta.ca ([138.73.1.138]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1P3Szk-0006yX-MU for gsmc-categories@m.gmane.org; Wed, 06 Oct 2010 14:21:16 +0200 Original-Received: from mlist.mta.ca ([138.73.1.63]:40550) by smtpx.mta.ca with esmtp (Exim 4.71) (envelope-from ) id 1P3Sz4-0004xC-FZ; Wed, 06 Oct 2010 09:20:34 -0300 Original-Received: from majordomo by mlist.mta.ca with local (Exim 4.71) (envelope-from ) id 1P3Syy-0000Jz-4F for categories-list@mlist.mta.ca; Wed, 06 Oct 2010 09:20:28 -0300 Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:6294 Archived-At: Following up on Paul Taylor's suggestion to " ... play around with skelet= ons, bones or even the Grim Reaper ... ", Vaughan Pratt = offered: > ... how about "scythe" for the functor [-,1+1]: C^op --> > C? In a Boolean topos this is just the (internal) contravariant power > object functor, but more generally it tends to cleave objects into thei= r > connected components in a suitable sense. But "scythe"? A scythe is for cutting off stalks, wholesale. (A sickle is for cutting them off ... umm ... retail, perhaps :-) .) To "cleave" an object in two one might utilize a *cleaver*, or, more = bluntly, a *wedge* -- but the resulting two parts are probably *not* in most instances "connected" at all, let alone "connected components": rather, they merely provide a binary coproduct decomposition of the given object. Cheers, -- Fred [For admin and other information see: http://www.mta.ca/~cat-dist/ ]