Abstract
Production systems are an established paradigm in knowledge representation, while ontologies are widely used to model and reason about the domain of an application. Description logics, underlying for instance the Web ontology language OWL, are a well-studied formalism to express ontologies. In this work we combine production systems (ps) and Description Logics (dl) in such a way that allows one to express both, facts and rules, using an ontology language. We explore the space of design options for combining the traditional closed world semantics of PS with the open world semantics of dl and propose a generic semantics for such combination. We show how to encode our semantics in a fixpoint extension of first-order logic. We show that in special cases (monotonic and light ps) checking properties of the system such as termination is decidable