Almost Definite Causal Theories

Abstract

The language of nonmonotonic causal theories, defined by Norman McCain and Hudson Turner, is an important formalism for representing properties of actions. For causal theories of a special kind, called definite, a simple translation into the language of logic programs under the answer set semantics is available. In this paper we define a similar translation for causal theories of a more general form, called almost definite. Such theories can be used, for instance, to characterize the transitive closure of a binary relation. The new translation leads to an implementation of a subclass of almost definite causal theories that employs the answer set solver smodels as the search engine.