In: Ipke Wachsmuth; Claus-Rainer Rollinger; Wilfried Brauer (Hrsg.). KI'95: Proceedings of the 19th Annual German Conference on Artificial Intelligence: Advances in Artificial Intelligence. German Conference on Artificial Intelligence (KI), Pages 125-136, Lecture Notes In Computer Science (LNCS), Vol. 981, ISBN 3-540-60343-3, Springer-Verlag, London, UK, 1995.