Approximation of Ontologies in CASL
Klaus Lüttich
International Conference on Formal Ontology in Information Systems (FOIS 2006)
Baltimore, Maryland (USA), November 9-11, 2006
Abstract
In this paper we present methods to generate a Description Logic (DL) theory from a given First Order Logic (FOL) theory, such that each DL axiom is entailed by the given FOL theory. This is obtained by rewriting the given FOL formulas. If this method is applied to an ontology specification in FOL the resulting DL specification is still grounded on the same semantics but clearly weaker than the FOL specification. The benefit of specification in DL is that it is decidable, and that efficient reasoning procedures are available as implemented in tools such as Racer, Fact++ or Pellet. Such ontologies in DL could be used for knowledge representation systems and the semantic web where efficient and decidable reasoning plays a major role. This method can be used to compile a foundational ontology formalised in FOL, like DOLCE (Descriptive Ontology for Linguistic and Cognitive Engineering), into DL for use with domain ontologies formalised in DL, or for the development of domain ontologies based on the compiled foundational ontology. These weakening strategies are described with CASL (Common Algebraic Specification Language), and one of its sublogics CASL-DL, and will be integrated into Hets (Heterogeneous Tool Set). Furthermore, this paper includes examples from DOLCE.