Building fuzzy hybrid Horn logic rules on top of ontologies

Description Logics (DL) has become popular knowledge representation formalisms for various applications in the Semantic Web. However, DL has its limit in knowledge representation ability as it can only represent one free variable at a time. Compared to DL, Horn logic covers different but overlapping areas of knowledge representation. This paper presents an approach to build Horn logic based rules on top of DL based ontologies. Uncertainty is an intrinsic feature of the world, especially in Semantic Web applications. Therefore, this paper also proposes fuzzy Horn logic to deal with vague knowledge. Finally, a reasoning procedure on the fuzzy hybrid knowledge base is addressed and exemplified.