A logic for object-oriented logic programming

Abstract

We present a logic for reasoning about complex objects, which is a revised and significantly extended version of Maier's O-logic [Mai86]. The logic naturally supports complex objects, object identity, deduction, is tolerant to inconsistent data, and has many other interesting features. It elegantly combines the object-oriented and value-oriented paradigms and, in particular, contains all of the predicate calculus as a special case. Our treatment of sets is also noteworthy: it is more general than ELPS [Kup87] and COL [AbG87], yet it avoids the semantic problems encountered in LDL [BNS87]. The proposed logic has a sound and complete resolution-based proof procedure.