| ## 5 Subsorting Michel Bidoit1 and Peter D. Mosses2 1 Laboratoire Spécification et Vérification, CNRS UMR 8643 École Normale Supérieure de Cachan 61, Avenue du Président Wilson, 94235 Cachan Cedex, France `bidoit@lsv.ens-cachan.fr` 2 University of Aarhus, BRICS and Department of Computer Science Aabogade 34, 8200 Aarhus N, Denmark `pdmosses@brics.dk` Abstract. Subsorts and supersorts are often useful in CASL specifications. Many examples naturally involve subsorts and supersorts. CASL provides means for the declaration of a sort as a subsort of another one when the values of the subsort are regarded a special case of those in the other sort. The aim of this chapter is to discuss and illustrate how to handle subsorts and supersorts in CASL specifications. LNCS 2900, pp. 57 - 66 Full article in PDF lncs@springer.de © Springer-Verlag Berlin Heidelberg 2004