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Combining knowledge representation and reasoning formalisms is an important and challenging task. It is important because non-trivial AI applications often comprise different aspects of the world, thus requiring suitable combinations of available formalisms modeling each of these aspects. It is challenging because the computational behavior of the resulting(More)
Motivated primarily by medical terminology applications, the prominent DL SHIQ has already been extended to a DL with complex role inclusion axioms of the form R • S ˙ R or S • R ˙ R, called RIQ, and the SHIQ tableau algorithm has been extended to handle such inclusions. This paper further extends RIQ and its tableau algorithm with important expressive(More)
We investigate the expressive power and computational properties of two different types of languages intended for speaking about distances. First, we consider a first-order language FM the two-variable fragment of which turns out to be undecidable in the class of distance spaces validating the triangular inequality as well as in the class of all metric(More)
In this paper, we compare various formalisms that have been recently introduced or used for distributed reasoning, ontology integration, and related topics; in particular, we focus on E-connections, Distributed Description Logics, and Package-based Description Logics. We then establish the relationship between these formalisms and various non-standard(More)
1 Motivation Combining description logics (DLs) with other logical formalisms, including other DLs, is an important and challenging task. Recent examples include: 1. the combination of DLs with temporal logics to form multi-dimensional temporal DLs, cf. e.g. [1, 6, 10]; 2. the fusion of multiple DLs into a single formalism that inherits decidability from(More)
We propose a novel technique for proving the consistency of large, complex and heterogeneous theories for which 'stan-dard' automated reasoning methods are considered insufficient. In particular, we exemplify the applicability of the method by establishing the consistency of the foundational ontology DOLCE, a large, first-order ontology. The approach we(More)
abstract. We introduce a new semantics for modal predicate logic, with respect to which a rich class of first-order modal logics is complete, namely all normal first-order modal logics that are extensions of free quantified K. This logic is defined by combining positive free logic with equality PFL. = and the propo-sitional modal logic K. We then uniformly(More)