From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/4980 Path: news.gmane.org!not-for-mail From: "Prof. Peter Johnstone" Newsgroups: gmane.science.mathematics.categories Subject: Re: Fundamental Theorem of Category Theory? Date: Tue, 16 Jun 2009 20:34:26 +0100 (BST) Message-ID: Reply-To: "Prof. Peter Johnstone" NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Trace: ger.gmane.org 1245246892 19703 80.91.229.12 (17 Jun 2009 13:54:52 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 17 Jun 2009 13:54:52 +0000 (UTC) To: Makoto Hamana , Original-X-From: categories@mta.ca Wed Jun 17 15:54:50 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 1MGvbE-0000zq-IF for gsmc-categories@m.gmane.org; Wed, 17 Jun 2009 15:54:48 +0200 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1MGupf-0006Xg-6Q for categories-list@mta.ca; Wed, 17 Jun 2009 10:05:39 -0300 Original-Sender: categories@mta.ca Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:4980 Archived-At: On Mon, 15 Jun 2009, Makoto Hamana wrote: > I have asked Prof. Yoneda many years ago why Yoneda Lemma is > called "Lemma", not "Theorem". He said that perhaps it was a > bit about internal of category theory rather than insisting > on applications to other mathematics. Doesn't Yoneda Lemma > satisfy (c) in Mile Gould's post? I don't know how much > Yoneda Lemma is useful in other areas of mathematics, and > I have wanted to know it. > When I lecture on category theory to first-year graduate students, I tell them there are two things they should remember about the Yoneda Lemma: it isn't a lemma, and it was never published by Yoneda. In this respect it resembles that bulwark of the British constitution, the Lord Privy Seal (who is none of the three things that his title claims). Peter Johnstone [For admin and other information see: http://www.mta.ca/~cat-dist/ ]