Applications Of Circumscription To Formalizing Common Sense Knowledge-英文文献.pdf

APPLICATIONS OF CIRCUMSCRIPTION TO FORMALIZING COMMON SENSE KNOWLEDGE John McCarthy Computer Science Department Stanford University Stanford CA jmccsstanfordedu httpwwwform alstanfordedujmc Abstract We present a new and more symmetric version of the circumscrip tion metho d of nonmonotonic reasoning rst describ ed in McCarthy and some applications to formalizing common sense knowledge The applications in this pap er are mostly based on minimizing the abnormality of dierent asp ects of various entities Included are non monotonic treatments of isa hierarchies the unique names hyp othe sis and the frame problem The new circumscription may b e called formula circumscription to distinguish it from the previously dened domain circumscription and pr edicate circumscription A still more general formalism called prioritize d circumscription is briey explored INTRODUCTION AND NEW DEFINITION OF CIRCUMSCRIPTION McCarthy intro duces the circumscription metho d of nonmonotonic reasoning and gives motivation some mathematical prop erties and some ex amples of its application The present pap er is logically selfcontained but motivation may b e enhanced by reading the earlier pap er We dont rep eat its arguments ab out the imp ortance of nonmonotonic reasoning in AI and its examples are instructive Here we give a more symmetric denition of circumscription and appli cations to the formal expression of common sense facts Our long term goal