Defeasible Inheritance Through Specialization
Typed substitution provides a means of capturing inheritance in logic deduction systems. However, in the presence of method overriding and multiple inheritance, inheritance is known to be nonmonotonic, and the semantics of programs becomes a problematic issue. This article attempts to provide a general framework, based on Dung's argumentation theoretic framework, for developing a natural semantics for programs with dynamic nonmonotonic inheritance. The relationship between the presented semantics and perfect-model (with overriding) semantics, proposed by Dobbie and Topor (1995), is investigated. It is shown that for inheritance-stratified programs, the two semantics coincide. However, the proposed semantics also provides correct skeptical meanings for the programs that are not inheritance-stratified.
argumentation nonmonotonic inheritance skeptical semantics inheritance stratification deductive object-oriented systems dynamic method resolution