LOOP-a language for LP-based AI applications

One major drawback of logic programming, particularly Prolog, is the lack of mechanisms for structuring knowledge (i.e. program clauses). This makes programming-in-the-large a difficult task even using the module system. To overcome this, various attempts were made to extend the logic programming paradigm with object-oriented features. We introduced LOOP previously (2000), a class-based, logic and object-oriented programming language, centered around the view of objects as persistent mutable terms with backtrackable state, which extends Prolog in a simple and straightforward fashion. To validate our ideas we recently developed a prototype based on expansion to Prolog code, implemented in Sicstus Prolog, a state of the art Prolog system which supports mutable terms with backtrackable destructive assignment.