Compiling high-level type constructors in constraint programming

Abstract. We propose high-level type constructors for constraint pro-gramming languages, so that constraint satisfaction problems can be modelled in very expressive ways. We design a practical set constraint language, called esra, by incorporating these ideas on top of opl. A set of rewrite rules achieves compilation from esra into opl, yielding pro-grams that are often very similar to those that a human opl modeller would (have to) write anyway, so that there is no loss in solving eciency.