Jos Lehmann

Editorial: Reasoning with Context in the Semantic Web

This Special Issue on Reasoning with Context in the Semantic Web collects ten articles that shed direct or indirect light on the role of context in Semantic Web theories and applications. Context has become a key-factor for the realization of the Semantic Web. There is a growing need for general and robust modeling and reasoning techniques that make it possible to handle the heterogeneity of knowledge, for instance, in situations where the same term has different meanings in different domains. Also the homogeneity of knowledge requires a context-based treatment, for instance, in situations where different terms have the same meaning in different domains, or where they may be seen as representing a coherent sub-domain. Research on these topics has mostly concentrated on the relationship between formal ontologies, which are the logical structures that encode the semantics of a software’s domain of application, and their context of use, or of development and maintenance, or of communication. This has resulted in

A Higher Order Approach to Ontology Evolution in Physics

A higher-order logical approach to ontology evolution is applied to examples in Physics. Based on this approach, a framework is proposed which includes a methodology for the formalisation of ontology evolution in higher-order logic and an implementation of this methodology in the theorem prover Isabelle. The proposed basic mechanisms for evolution are called ontology repair plans. These operate on ontologies formalised as contexts, i.e., as multiple logical theories. In such a setting, ontologies may contradict one another or introduce redundancies with respect to one another, without any of them containing logical contradictions or redundancies. When, though, an inconsistency or a redundancy between two or more ontologies becomes explicit, it may be resolved by the application of an ontology repair plan, as each plan compiles together a pattern for diagnosis and transformation rules for effecting a repair. The repair can combine the retraction and/or addition of axioms as well as the deeper modification of the language in which the ontology is represented.