Jeff Heflin CSE Pan http://www.lehigh.edu/~zhp2 zhp2@lehigh.edu Zhengxiang Pan Zhengxiang Pan (610)758-4719 Zhengxiang Computer Science & Engineering 2004 Semantic Web Languages A Model Theoretic Semantics for Ontology Versioning versioning Lehigh University USA Lehigh Univeristy Bethlehem, PA, USA