From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/4824 Path: news.gmane.org!not-for-mail From: PETER EASTHOPE Newsgroups: gmane.science.mathematics.categories Subject: Elementary concepts of map objects Date: Fri, 08 May 2009 10:41:02 -0700 Message-ID: Reply-To: PETER EASTHOPE NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1242134870 19099 80.91.229.12 (12 May 2009 13:27:50 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 12 May 2009 13:27:50 +0000 (UTC) To: categories@mta.ca Original-X-From: categories@mta.ca Tue May 12 15:27:40 2009 Return-path: Envelope-to: gsmc-categories@m.gmane.org Original-Received: from mailserv.mta.ca ([138.73.1.1]) by lo.gmane.org with esmtp (Exim 4.50) id 1M3s0w-000375-Ce for gsmc-categories@m.gmane.org; Tue, 12 May 2009 15:27:22 +0200 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M3r6C-00028K-N6 for categories-list@mta.ca; Tue, 12 May 2009 09:28:44 -0300 Content-language: en Content-disposition: inline Original-Sender: categories@mta.ca Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:4824 Archived-At: In light of the recent discussion here about the "horizontal line notation", I've returned to the introduction to map objects in L. & S., _Conceptual Mathematics_. This statement is in the rectangle at the top of page 314. ( Script.ChangeFont Courier8 ) T e X ----> Y T x Y ----> Y induces ------------- T x X ----> Y Evaluation map e induces a "correspondence". Is this horizontal line an implication or an equivalence or a map or a bijection? "Induces" seems plausible but exactly what is meant? Thanks, ... Peter E.