Practical Reasoning for Expressive Description Logics

Abstract. Description Logics (DLs) are a family of knowledge representation formalisms mainly characterised by constructors to build complex concepts and roles from atomic ones. Expressive role constructors are important in many applications, but can be computationally problematical. We present an algorithm that decides satisfiability of the DL ALC extended with transitive and inverse roles, role hierarchies, and qualifying number restrictions. Early experiments indicate that this algorithm is well-suited for implementation. Additionally, we show that ALC extended with just transitive and inverse roles is still in PSpace. Finally, we investigate the limits of decidability for this family of DLs. 1 Motivation Description Logics (DLs) are a well-known family of knowledge representation formalisms [DLNS96]. They are based on the notion of concepts (unary predicates, classes) and roles (binary relations), and are mainly characterised by constructors that allow complex concepts and roles t...

• Type: Conference
• Year: 1999
• Where: LPAR
• Authors: Ian Horrocks, Ulrike Sattler, Stephan Tobies
• Keywords: Automated Reasoning, Complex Concepts, Inverse Roles, Knowledge Representation Formalisms, LPAR 1999