Accession Number : ADA198146

Title :   Pattern-Directed Invocation with Changing Equalities.

Descriptive Note : Memorandum rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE ARTIFICIAL INTELLIGENCE LAB

Personal Author(s) : Feldman, Yishai A ; Rich, Charles

PDF Url : ADA198146

Report Date : May 1988

Pagination or Media Count : 46

Abstract : The interaction of pattern-directed invocation with equality in an automated reasoning system give rise to a completeness problem. In such systems, a demon needs to be invoked not only when its pattern exactly matches a term in the reasoning data base, but also when it is possible to create a variant that matches. An incremental algorithm has been developed, which solves this problem without generating all possible variants of terms in the data base. The algorithm is shown to be complete for a class of demons, called transparent demons, in which there is a well-behaved logical relationship between the pattern and the body of the demon. Completeness is maintained when new demons, new terms, and new equalities are added in any order. Equalities can also be retracted via a truth maintenance system. The algorithm has been implemented as part of a reasoning system called BREAD. (KR)

Descriptors :   *ALGORITHMS, *REASONING, AUTOMATION, PATTERNS, DATA BASES, MAINTENANCE, VARIATIONS, ALGORITHMS, AUTOMATION, PATTERN RECOGNITION, DATA BASES, MAINTENANCE, REASONING, VARIATIONS

Subject Categories : Cybernetics

Distribution Statement : APPROVED FOR PUBLIC RELEASE