ECAI 2002 : 15th European Conference on Artificial Intelligence, July 21-26, 2002, Lyon, France : including Prestigious Applications of Intelligent Systems (PAIS-2002) : proceedings / ed. by Frank van HarmelenHandbook of knowledge representation / edited by Frank van Harmelen, Vladimir Lifschitz, Bruce PorterHandbook of knowledge representation / edited by Bruce Porter, Vladimir Lifschitz and Frank van Harmelen