From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/5995 Path: news.gmane.org!not-for-mail From: Russ Abbott Newsgroups: gmane.science.mathematics.categories Subject: Reducibility Date: Mon, 19 Jul 2010 09:46:08 -0700 Message-ID: Reply-To: Russ Abbott NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 X-Trace: dough.gmane.org 1279634139 25101 80.91.229.12 (20 Jul 2010 13:55:39 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Tue, 20 Jul 2010 13:55:39 +0000 (UTC) To: categories@mta.ca Original-X-From: categories@mta.ca Tue Jul 20 15:55:35 2010 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 4.69) (envelope-from ) id 1ObDIF-0002PM-ED for gsmc-categories@m.gmane.org; Tue, 20 Jul 2010 15:55:35 +0200 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1ObCml-0006hb-VD for categories-list@mta.ca; Tue, 20 Jul 2010 10:23:04 -0300 Original-Sender: categories@mta.ca Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:5995 Archived-At: Hi, I apologize if this is off topic. I'm not sure where to direct this question. I'm interested in when one can say that one theory is reducible to another. Reducibility is defined: a set A is T-reducible to a set B if there is a function f of type T such that x is a member of A if and only if f(x) is a member of B. Mathematical groups are defined in terms of a 0 element, other elements, and an operation with certain properties. Let A be the set of mathematical groups (set of models of groups?). Is there an interesting set B and function type T so that A is T-reducible to B? First of all, is that an interesting question to ask? If so, how would one go about thinking about it? Thanks for any help or pointers you can give me. -- Russ Abbott ______________________________________ Professor, Computer Science California State University, Los Angeles cell: 310-621-3805 Google voice: 424-2Blue4 blog: http://russabbott.blogspot.com/ vita: http://sites.google.com/site/russabbott/ ______________________________________ [For admin and other information see: http://www.mta.ca/~cat-dist/ ]