Herbert Kuchen S. Doaitse Swierstra Programming Languages: Implementations, Logics, and Programs, 8th International Symposium, PLILP'96, Aachen, Germany, September 24-27, 1996, Proceedings PLILP Lecture Notes in Computer Science 1140 Springer 1996 3-540-61756-6 db/conf/plilp/plilp96.html