In: Dieter Hutter; Werner Stephan; P. Traverso; M. Ullmann (Hrsg.). Proceedings Current Trends in Applied Formal Methods. International Workshop on Current Trends in Applied Formal Methods (FM-Trends-98), Boppard, Germany, Pages 351-358, Lecture Notes in Computer Science (LNCS), Vol. 1641, ISBN 978-3-540-66462-8, Springer-Verlag, Berlin, Heidelberg, 1999.