From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/2312 Path: news.gmane.org!not-for-mail From: jlipton@wesleyan.edu Newsgroups: gmane.science.mathematics.categories Subject: Re: Semantic tableaux and intuitionistic logic Date: Mon, 2 Jun 2003 09:02:07 -0400 (EDT) Message-ID: References: <20030530201401.40220.qmail@web12203.mail.yahoo.com> NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Trace: ger.gmane.org 1241018566 3492 80.91.229.2 (29 Apr 2009 15:22:46 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 29 Apr 2009 15:22:46 +0000 (UTC) To: categories@mta.ca Original-X-From: rrosebru@mta.ca Mon Jun 2 17:35:29 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 02 Jun 2003 17:35:29 -0300 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 19Mw0v-0004eP-00 for categories-list@mta.ca; Mon, 02 Jun 2003 17:34:41 -0300 In-Reply-To: <20030530201401.40220.qmail@web12203.mail.yahoo.com> X-ECS-MailScanner: Found to be clean Original-Sender: cat-dist@mta.ca Precedence: bulk X-Keywords: X-UID: 2 Original-Lines: 34 Xref: news.gmane.org gmane.science.mathematics.categories:2312 Archived-At: Nerode, Shore: logic for Applications, Springer, has detailed tableau development for intuitionistic, and modal logics: i.e. there is nothing intrinsically classical about the method. The ideas go back to Hintikka and Beth (at least) in the 1950s and 60s. On Fri, 30 May 2003, Galchin Vasili wrote: > Hello, > > I am only familiar with semantic tableaux for > classical propositional logic (and classical 1st order > logic). It seems that as an inference system it is > based squarely around the law of the excluded middle > because it is essentially reductio ad absurdum. Hence, > as an inference system it can't be simply modified for > intuitionistic propositional calculus?? (Of course, I > am bringing this because the role that Heyting > algebras play in Topos theory). > > Regards, Bill Halchin > > > -------------------------------------------------------------------- Jim Lipton Math Dept.Wesleyan University, Middletown,CT 06459-0128 www.wesleyan.edu/~jlipton jlipton@wesleyan.edu, (860) 685-2188 fax:685-2571 ====================================================================