VAL@SAIL.STANFORD.EDU (Vladimir Lifschitz) (10/20/86)
MORE AGENTS ARE BETTER THAN ONE Michael Georgeff Artificial Intelligence Center SRI International Thursday, October 23, 4pm MJH 252 A recent paper by Steve Hanks and Drew Mcdermott shows how some previous "solutions" to the frame problem turn out to be inadequate, despite appearances otherwise. They use a simple example -- come to be called the "Yale Shooting Problem" -- for which it is impossible to derive some expected results -- in this case, that the target of a shooting event ceases living. Such difficulties, they suggest, call into question the utility of nonmonotonic logics for solving the frame problem. In this talk, we describe a theory of action suited to multiagent domains, and show how this formulation avoids the problems raised by Hanks and McDermott. In particular, we show how the Yale Shooting Problem can be solved using a generalized form of the situation calculus for multiagent domains, together with notions of causality and independence. The solution does not rely on complex generalizations of nonmonotonic logics or circumscription, but instead uses traditional circumscription. We will also argue that most problems traditionally viewed as involving a single agent are better formulated as multiagent problems, and that the frame problem, as usually posed, is not what we should be attempting to solve.