Abstract. In this paper, we consider the resolution of constraint satisfaction problems in the case where the variables of the problem are subsets of R n . In order to use a constraint propagation approach, we introduce sets intervals, which are sets of subsets of R n with a lower bound and an upper bound with respect to the inclusion. Then, we propose an arithmetic for them. This makes possible to build projection operators that are then used by the propagation. In order to illustrate the principle and the efficiency of the approach, a testcase is provided.