2002 pfps@research.bell-labs.com Peter F Patel-Schneider Peter F. Patel-Schneider http:/www.bell-labs.com/user/pfps/ dieter@cs.vu.nl Dieter Fensel Dieter Fensel http:/www.cs.vu.nl/~dieter/

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Murray Hill, New Jersey U. S. A. Bell Labs Research http://www.bell-labs.com/ Amsterdam The Netherlands Vrije Universiteit Amsterdam