Consistency in General CSPs

Abstract

In this paper, we introduce a new form of consistency in general constraint satisfaction problems (CSPs), called ω-pairwise-consistency which can be applied to both binary and non-binary constraints. Enforcing ω-pairwise-consistency in a CSP simplifies the problem representation by removing those tuples from the given constraints that will not participate in any solution. Typical CSP solving algorithms can then solve the simplified CSP more efficiently. We show that ω-pairwise-consistency is stronger than some other forms of consistency reported in the literature. We also present an algorithm for achieving ω-pairwise-consistency.