Accession Number : ADA259784
Title : Resolving Ambiguity in Nonmonotonic Inheritance Hierarchies
Descriptive Note : Memorandum rept.
Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE ARTIFICIAL INTELLIGENCE LAB
Personal Author(s) : Stein, Lynn A
Report Date : Aug 1991
Pagination or Media Count : 45
Abstract : This paper describes a theory of inheritance theories. We present an original theory of inheritance in nonmonotonic hierarchies. The structures on which this theory is based delineate a framework that subsumes most inheritance theories in the literature, providing a new foundation for inheritance. Our path-based theory is sound and complete w.r.t. a direct model-theoretic semantics. Both the credulous and the skeptical conclusions of this theory are polynomial-time computable. We prove that true skeptical inheritance is not contained in the language of path-based inheritance. Because our techniques are modular w.r.t. the definition of specificity, they generalize to provide a unified framework for a broad class of inheritance theories. By describing multiple inheritance theories in the same 'language' of credulous extensions, we make principled comparisons rather than the ad-hoc examination of specific examples makes up most of the comparative inheritance work.
Descriptors : *REASONING , *MODEL THEORY , *HIERARCHIES , MODELS , PATHS , POLYNOMIALS , LOGIC , LANGUAGE , TRACTABLE , SEMANTICS , COMPARISON
Subject Categories : Psychology
Distribution Statement : APPROVED FOR PUBLIC RELEASE