From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/9290 Path: news.gmane.org!.POSTED!not-for-mail From: Dana Scott Newsgroups: gmane.science.mathematics.categories Subject: An elementary question Date: Sun, 13 Aug 2017 12:55:11 -0700 Message-ID: Reply-To: Dana Scott NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 (Mac OS X Mail 10.3 \(3273\)) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: blaine.gmane.org 1502667667 11308 195.159.176.226 (13 Aug 2017 23:41:07 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sun, 13 Aug 2017 23:41:07 +0000 (UTC) To: categories@mta.ca Original-X-From: majordomo@mlist.mta.ca Mon Aug 14 01:41:01 2017 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 1dh2V3-000258-05 for gsmc-categories@m.gmane.org; Mon, 14 Aug 2017 01:40:53 +0200 Original-Received: from mlist.mta.ca ([138.73.1.63]:43579) by smtp2.mta.ca with esmtp (Exim 4.80) (envelope-from ) id 1dh2US-0000cF-VA; Sun, 13 Aug 2017 20:40:16 -0300 Original-Received: from majordomo by mlist.mta.ca with local (Exim 4.71) (envelope-from ) id 1dh2U9-0000c9-3y for categories-list@mlist.mta.ca; Sun, 13 Aug 2017 20:39:57 -0300 Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:9290 Archived-At: The category of posets (= partially ordered sets) and monotone maps is often used as an easy example -- different from the category of sets -- that has products, coproducts, and is cartesian closed but not a topos. Let P and Q be two posets. Define (P (<) Q) as the modified coproduct where all the elements of P are made less than all the elements of Q. QUESTION. Does (P (<) Q) have a nice categorical definition as a functor in the category of posets? [For admin and other information see: http://www.mta.ca/~cat-dist/ ]