STORY%MIT-MC@sri-unix.UUCP (09/20/84)
From: Kenneth Byrd Story <STORY @ MIT-MC> [Forwarded from the MIT bboard by SASW@MIT-MC.] DATE: Wednesday, September 26, 1984 TIME: Refreshments, 3:45pm Lecture, 4:00pm PLACE: NE43-453 TITLE: ``A MODEL-THEORETIC ANALYSIS OF KNOWLEDGE'' SPEAKER: Dr. Joseph Y. Halpern, IBM, San Jose Understanding knowledge is a fundamental issue in many disciplines. In computer science, knowledge arises not only in the obvious contexts (such as knowledge-based systems), but also in distributed systems (where the goal is to have each processor know something, as in Byzantine agreement). A general semantic model of knowledge is introduced, to allow reasoning about statements such as "He knows that I know whether or not she knows whether or not it is raining." This approach more naturally models a state of knowledge than previous proposals (including Kripke structures). Using this notion of model, a model theory for knowledge is developed. This theory enables one to interpret such notions as a "finite amount of information" and "common knowledge" in different contexts. This is joint work with Ron Fagin and Moshe Vardi. HOST: Professor Silvio Micali