This paper presents a tableaux calculus for deciding the concept satis- ability problem of the new description logic ALCRA and discusses some open problems. ALCRA augments the description logic ALC with role inclusion axioms of the form S T v R 1 t : : : tR n . Additionally, all roles

This paper describes first steps towards an efficient implementation of a tableau calculus for the logic T L ALC of [14, 11], a temporal extension of the standard description logic ALC. T L ALC extends ALC by means of the temporal operators fl (next) and U (until) which are applied to concepts

Abstract. We introduce a new proof system for the description logic ALC in the framework of the calculus of structures, a structural proof theory that employs deep inference. This new formal presentation introduces positive proofs for description logics. Moreover, this result makes possible

knowledge base is used to define new concepts in terms of primitive concepts and relations. The topic of this paper is the effect of the available operations in a DL on the length and the syntactic shape of definitions in a Terminology Box. Defining new concepts can be done in two ways: (1

This paper describes the logic ALCH R + , which extends ALC R + with a primitive role hierarchy, and presents an appropriate extension to the ALCR + satisfiability testing algorithm. ALCH R + is of interest because it provides useful additional expressive power and, although its satisfiability

of ABox statements) to be entailed. Klarman et al [8] have provided an algorithm for performing ABox abduction in the description logic ALC by converting the knowledge base and observation to first-order logic, using a connection tableau to obtain abductive solutions, and then converting these back to DL

but also combining it with classical negation seems to be useful and necessary due to their respective features corresponding to predicate denial (e.g., not happy) and predicate term negation (e.g., unhappy). In this paper, we propose an alternative description logic ALC∼ with classical negation and strong

Abstract. Aggregated objects play an important role in many knowledge representation applications. For the adequate representation of aggregated objects, it is crucial to represent part-whole relations. We discuss properties of part-whole relations and extend the description logic ALC with means

We present the fuzzy description logic ALCF H where primitive concepts are modified by means of hedges taken from hedge algebras. ALCF H is strictly more expressive than Fuzzy-ALC defined in [9]. We show that given a linearly ordered set of hedges primitive concepts can be modified to any desired

Abstract. We show that global caching can be used with propagation of both satisfiability and unsatisfiability in a sound manner to give an EXPTIME algorithm for checking satisfiability w.r.t. a TBox in the basic description logic ALC. Our algorithm is based on a simple traditional tableau calculus