Abstract

Web ontology languages play an important role in the Semantic Web, and its approach to knowledge representation on the web can be adopted to represent knowledge in the knowledge grid model and system. However, the logic foundation of web ontology languages needs to be further explored. This paper presents a predicate-ordered logic, called Predicate-Ordered Sort-Ordered Logic (POSOL), as a rigid logic framework for knowledge representation on the web. Based on an order-sorted logic for knowledge representation, it introduces a partially ordering on predicates to model the sub-property construct in web ontology languages such as RDFS and OWL. Some structures and properties of the POSOL signature and the POSOL knowledge base are studied. The bridging between the POSOL and the order-sorted logic is given. In addition, it briefly discusses the mappings from RDFS and OWL into POSOL, as well as some usage of POSOL within the knowledge grid model.

Author Keywords: Knowledge grid; Semantic Web; Knowledge representation; Order-sorted logic; Predicate-ordered

Article Outline

1. Introduction

2. Syntax

2.1. Signature

2.2. Σ-Formulae

2.3. POSOL knowledge base

3. Semantics

3.1. Interpretations

3.2. Models of POSOL knowledge base

4. Discussion

4.1. Mapping RDFS and OWL into POSOL

4.2. The usage of POSOL within the knowledge grid model

4.3. Comparison with related works

5. Conclusion

Acknowledgements

References

Vitae