Extended Prolog with Logical Constraint Descriptions

Abstract

HYPOSE is an extended prolog with logical constraint descriptions. The declarative interpretation of the inference of HYPOSE is to find a subset D of the given hypothesis set⊿, such that the union of fact set F and D implies the given query Q under the restriction that the union of F and D does not imply the given constraint C. Procedurally, the constraint works as a demon that watches the execution of the query Q so as not to violate the given constraint C. HYPOSE increases the expressive power of constraints, since we can write constraints in the same logical way as we write programs in prolog. It allows us to implement a very efficient inference with constraints, since the consttaint demon can work incrementally. It supplies a natural framework for dealing logically with hypotheses and changing knowledge base, while standard prolog does not give a good logical treatment for them.