Semantic Web in a Nutshell

Abstract

The paper outlines selected topics related to Semantic Web. We start with problems with the use of current web search engines. Next, we discuss the architecture and basic concepts of Semantic Web whose central ideas focus around ontologies. We show the role of logics in the specification and verification of ontologies as well as reasoning about them. We mainly concentrate on rule languages. In particular we discuss the 4QL query language supplying the user with simple, yet powerful con-structs for filling gaps in missing knowledge as well as for disambiguation of inconsistencies.