From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/9670 Path: news.gmane.org!.POSTED!not-for-mail From: =?UTF-8?B?Wm9yYW4gxaBrb2Rh?= Newsgroups: gmane.science.mathematics.categories Subject: Re: Sheaf terminology question Date: Tue, 17 Jul 2018 10:48:25 +0200 Message-ID: Reply-To: =?UTF-8?B?Wm9yYW4gxaBrb2Rh?= NNTP-Posting-Host: blaine.gmane.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Trace: blaine.gmane.org 1531838717 9779 195.159.176.226 (17 Jul 2018 14:45:17 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 17 Jul 2018 14:45:17 +0000 (UTC) Cc: Categories To: Andrew Pitts Original-X-From: majordomo@mlist.mta.ca Tue Jul 17 16:45:13 2018 Return-path: Envelope-to: gsmc-categories@m.gmane.org Original-Received: from smtp2.mta.ca ([198.164.44.40]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1ffRE0-0002QZ-Nd for gsmc-categories@m.gmane.org; Tue, 17 Jul 2018 16:45:12 +0200 Original-Received: from mlist.mta.ca ([138.73.1.63]:34141) by smtp2.mta.ca with esmtp (Exim 4.80) (envelope-from ) id 1ffREz-0004pL-44; Tue, 17 Jul 2018 11:46:13 -0300 Original-Received: from majordomo by mlist.mta.ca with local (Exim 4.71) (envelope-from ) id 1ffREJ-0007GD-Ag for categories-list@mlist.mta.ca; Tue, 17 Jul 2018 11:45:31 -0300 Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:9670 Archived-At: Late Alexander L. Rosenberg used the term epipresheaf in that case; I am not sure if he learned it somewhere or he made it up. The reasoning behind the terminology is clear. Zoran =C5=A0koda On 16 Jul 2018 14:10, "Andrew Pitts" wrote: > Given a coverage on a small category, the condition for a Set-valued > presheaf on the category to be a sheaf has an existence part and a > uniqueness part. If only the uniqueness part holds, one says that the > presheaf is separated. Is there a name out there for presheaves that only > satisfy the existence part of the sheaf condition? > > Andy Pitts > > [For admin and other information see: http://www.mta.ca/~cat-dist/ ]