Finite Set Constraints in Oz

We report on the extension of the concurrent constraint language Oz by constraints over finite sets of integers. Set constraints are an important addition to the constraint programming system Oz and are very employable in natural language processing and general problem solving. This extension profits much from its integration with the existing constraint systems over finite domains and feature trees, as well as from the availability of first-class procedures. This combination of features is unique to Oz. This paper focuses on the expressiveness gained by set constraints and on the benefits of the integration with finite domain constraints. A number of case studies demonstrates programming techniques exploring these advantages.