Declaratively Querying and Visualizing Knowledge Bases in XML

Abstract. The maintenance of large knowledge systems usually is a rather com-plex task. In this paper we will show that extensions or modifications of a knowledge base can be supported by appropriate visualizations techniques, e.g. by il-lustrating dependencies of the considered knowledge. In particular, we introduce a declarative approach for querying and visualizingrule-based knowledge represented as X ML documents; a knowledge engineer canextract and visually inspect parts of the knowledge base by ad-hoc declarations in a flexible manner.