VAL@SAIL.STANFORD.EDU (Vladimir Lifschitz) (03/18/87)
CIRCUMSCRIPTIVE THEORIES Vladimir Lifschitz Thursday, March 19, 4pm Bldg. 160, Room 161K The use of circumscription for formalizing commonsense knowledge and reasoning requires that a circumscription policy be selected for each particular application: we should specify which predicates are circumscribed, which predicates and functions are allowed to vary, what priorities between the circumscribed predicates are established, etc. The circumscription policy is usually described either informally or using suitable metamathematical notation. In this talk a simple and general formalism will be proposed which permits describing circumscription policies by axioms, included in the knowledge base along with the axioms describing the objects of reasoning.