A rule-based language with functions and sets

Abstract

A logic based language for manipulating complex objects constructed using set and tuple constructors is introduced. A key feature of the COL language is the use of base and derived data functions. Under some stratification restrictions, the semantics of programs is given by a minimal and justified model that can be computed using a finite sequence of fixpoints. The language is extended using external functions and predicates. An implementation of COL in a functional language is briefly discussed.