clarke@utcsri.UUCP (Jim Clarke) (10/14/86)
LATE ANNOUNCEMENT ARTIFICIAL INTELLIGENCE SEMINAR Tuesday, October 21, 3 p.m., in Galbraith 119 Dr. Vladimiar Lifschitz Stanford University "Default Reasoning and the Frame Problem" We apply McCarthy's theory of circumscription to formalizing reasoning about action and change. Formal theories of action include axioms describ- ing the changes that take place in the world when actions are performed. In addition, it is necessary to postulate that the only changes in the state of the world are those that are implied by these axioms. The problem of formalizing this assumption is known as the "frame problem". It has long been recognized that this problem is closely related to the theory of default reasoning, but attempts to apply existing formalizations of default reasoning to the frame problem have led to significant technical difficul- ties. We show that these difficulties can be overcome if causality is included in the theory as an additional primitive concept. -- Jim Clarke -- Dept. of Computer Science, Univ. of Toronto, Canada M5S 1A4 (416) 978-4058 {allegra,cornell,decvax,linus,utzoo}!utcsri!clarke