From owner-cse663-fa06-list@LISTSERV.BUFFALO.EDU Sun Nov 5 18:26:27 2006 Received: from ares.cse.buffalo.edu (ares.cse.Buffalo.EDU [128.205.32.79]) by castor.cse.Buffalo.EDU (8.13.6/8.12.10) with ESMTP id kA5NQQS7025142 for ; Sun, 5 Nov 2006 18:26:26 -0500 (EST) Received: from front3.acsu.buffalo.edu (upfront.acsu.buffalo.edu [128.205.4.140]) by ares.cse.buffalo.edu (8.13.6/8.13.6) with SMTP id kA5NQNsn045440 for ; Sun, 5 Nov 2006 18:26:23 -0500 (EST) Received: (qmail 75 invoked from network); 5 Nov 2006 23:26:23 -0000 Received: from mailscan4.acsu.buffalo.edu (128.205.6.136) by front3.acsu.buffalo.edu with SMTP; 5 Nov 2006 23:26:23 -0000 Received: (qmail 306 invoked from network); 5 Nov 2006 23:26:23 -0000 Received: from deliverance.acsu.buffalo.edu (128.205.7.57) by front2.acsu.buffalo.edu with SMTP; 5 Nov 2006 23:26:23 -0000 Received: (qmail 16637 invoked from network); 5 Nov 2006 23:26:10 -0000 Received: from listserv.buffalo.edu (128.205.7.35) by deliverance.acsu.buffalo.edu with SMTP; 5 Nov 2006 23:26:10 -0000 Received: by LISTSERV.BUFFALO.EDU (LISTSERV-TCP/IP release 14.5) with spool id 1702383 for CSE663-FA06-LIST@LISTSERV.BUFFALO.EDU; Sun, 5 Nov 2006 18:26:10 -0500 Delivered-To: CSE663-FA06-LIST@LISTSERV.BUFFALO.EDU Received: (qmail 22981 invoked from network); 5 Nov 2006 23:26:10 -0000 Received: from mailscan3.acsu.buffalo.edu (128.205.6.135) by listserv.buffalo.edu with SMTP; 5 Nov 2006 23:26:10 -0000 Received: (qmail 24879 invoked from network); 5 Nov 2006 23:26:08 -0000 Received: from castor.cse.buffalo.edu (128.205.32.14) by smtp2.acsu.buffalo.edu with SMTP; 5 Nov 2006 23:26:08 -0000 Received: from castor.cse.Buffalo.EDU (rapaport@localhost [127.0.0.1]) by castor.cse.Buffalo.EDU (8.13.6/8.12.10) with ESMTP id kA5NQ8Ub025126 for ; Sun, 5 Nov 2006 18:26:08 -0500 (EST) Received: (from rapaport@localhost) by castor.cse.Buffalo.EDU (8.13.6/8.12.9/Submit) id kA5NQ8fX025125 for CSE663-FA06-LIST@LISTSERV.BUFFALO.EDU; Sun, 5 Nov 2006 18:26:08 -0500 (EST) X-UB-Relay: (castor.cse.buffalo.edu) X-PM-EL-Spam-Prob: : 7% Message-ID: <200611052326.kA5NQ8fX025125@castor.cse.Buffalo.EDU> Date: Sun, 5 Nov 2006 18:26:08 -0500 Reply-To: CSE 663 - Advanced Knowledge Representation - Fall 2006 Sender: CSE 663 - Advanced Knowledge Representation - Fall 2006 From: "William J. Rapaport" Subject: Re: Paths To: CSE663-FA06-LIST@LISTSERV.BUFFALO.EDU Precedence: list List-Help: , List-Unsubscribe: List-Subscribe: List-Owner: X-UB-Relay: (castor.cse.buffalo.edu) X-DCC-Buffalo.EDU-Metrics: castor.cse.Buffalo.EDU 1336; Body=0 Fuz1=0 Fuz2=0 X-Virus-Scanned: ClamAV 0.88.3/2163/Sun Nov 5 12:42:14 2006 on ares.cse.buffalo.edu X-Virus-Status: Clean Status: R Content-Length: 2161 | Date: Sat, 4 Nov 2006 12:16:08 -0500 | From: Shane Axtell | Subject: Paths | To: CSE663-FA06-LIST@LISTSERV.BUFFALO.EDU | Is it possible to use SNePSLOG rules (e.g. if x then y) instead of defining | paths? If so, could you give us an example? There's no clear principle on when to use rules vs. when to use paths. In some cases, you can use either one: Suppose: Fido is a dog. Dogs are mammals. So, Fido is a mammal. We can represent the relationship of class membership to the subset relation either as a rule: (assert forall ($x $y $z) &ant (build member *x class *y) &ant (build subclass *y superclass *z) cq (build member *x class *z)) Or as a path: (define-path class (compose class (kstar (compose subclass ! superclass)))) Which to use? Rule-based inference is "conscious", in the sense that Cassie explicitly believes the rule. Path-based inference is "subconscious", in the sense that she has no explicit beliefs about the paths. For discussion, see: Stuart C. Shapiro. Cables, paths and ``subconscious'' reasoning in propositional semantic networks. In John F. Sowa, editor, Principles of Semantic Networks, chapter 4, pages 137-156. Morgan Kaufmann, San Mateo, CA, 1991. http://www.cse.buffalo.edu/~shapiro/Papers/cablesnpaths.ps Arguably, you might use rules when you firmly believe that a relationship is best expressed by a universally quantified rule and paths when you think that the relationship might be defeasible (e.g., "birds fly"). You could even use path-based inference with rules. E.g., given the rule about membership in superclasses, above, you could define a *path* through the rule and use path-based inference instead of rule-based inference. I'll leave the details to your imagination. For a paper on when this might be appropriate, see: S. L. Peters, S. C. Shapiro, and W. J. Rapaport. Flexible natural language processing and Roschian category theory. In Proceedings of the Tenth Annual Conference of the Cognitive Science Society, pages 125-131. Lawrence Erlbaum Publishers, 1988. http://www.cse.buffalo.edu/~rapaport/Papers/Papers.by.Others/peters.10annual.pdf