A reasoning framework for heterogeneous XML

XML is designed to structure data for exchange. It is also a new trend to use XML to encode knowledge on the Web. An important project for this purpose is the semantic Web of W3C. They proposed several specifications, including RDF/RDFS and OWL, for knowledge representation. In the architecture of SW, they proposed XML for the syntax layer, RDF/RDFS for the semantics layer, and OWL for the ontology layer. However, languages for the logic layer and proof layer are not yet defined. We propose a different approach for knowledge representation and reasoning. We define a logic-based framework to transform XML documents into logical facts, and to reason about these facts. The transforming and reasoning processes are based on a logic programming language, path inference language (PIL), which is specifically designed for tree-structure documents like XML. People may write a PIL program to extract logical facts from XML documents, and the extracted logical facts are imported into a logic-based ontology in PIL for reasoning. Based on PIL, we intend to develop a simple and powerful framework for people to interpret the semantics of XML easily.