A Programming Tool for Management of a Predicate-Calculus-Oriented Data Base

This paper describes a LISP program, cal led PCDB, for storage and re t r i eva l in a data base of predicate calculus (PC) formulas. The PCDB pacxage uses standardized representations of PC formulas, where ground unit clauses are stored e f f i c i e n t l y , e.g. on the proper tyl is ts of t he i r arguments, and other clauses have other representation. The major part of the PCDB package is a function generator, which accepts declarations of PC relat ions and functions, and Which also accepts "ru les" (= non-ground axioms intended for use in deduction) Declarations and rules are used to generate e f f i c ien t code for storage and re t r i eva l of " facts" (usually = ground uni t clauses) in and from the data base. This generation process may be characterized as a "compilation" of the rules (from predicate calculus to LISP).