Improving domain filtering using restricted path consistency

This paper introduces a new level of partial consistency for constraint satisfaction problems, which is situated between arc and path-consistency. We call this level restricted path-consistency (RPC). Two procedures to enforce complete and partial RPC are presented. They both use path-based verifications to detect inconsistencies but retain the good features of arc-consistency since they only touch the variables domains and do not augment the connectivity of the constraint graph. We show that, although they perform a limited number of checks, these procedures exhibit a considerable pruning power