Merging Objects and Logic Programming: Relational Semantics

Abstract

This paper proposes new semantics for merging object pro-gramming into logic programming. It differs from previous at-tempts in that it takes a relational view of method evaluation and inheritance mechanisms originating from object program-ming. A tight integration is presented, an extended rationale for adopting a success/failure semantics of backtrackable methods calls and for authorizing variable object calls is given. New method types dealing with non monotonicity and deter-minism necessary for this tight integration are discussed. The need for higher functions is justified from a user point of view. as well as from an implementation one. The system POL is only a piece of a more ambitious goal which is to merge logic programming, object programming and semantic data models which can be seen as an attempt to bridge the gap between AI and databases. The paper is restricted to a programming perspective. 1.