Reflection as a Tool for Integration: An Exercise in Procedural Introspection

This paper reports on a quite large experience in implementing a procedurally introspective system (PIS), ALICE, in which a well known problem is faced: the integration between LISP and Horn clauses. This exercise is motivated by a recognized lack of experience in implementing PISs to deal with actual A.I. programming problems. ALICE is composed of two procedurally introspective languages based on LISP and on Horn clauses, respectively. The integration is achieved by means of a new kind of reflection called mutuai reflection. The design of ALICE required the generalization of several concepts and mechanisms introduced in 3-LISP. The discussion is completed with a set of general retrospective considerations.