Failed Value Consistencies for Constraint Satisfaction

Abstract. In constraint satisfaction, basic inferences rely on some properties of constraint networks, called consistencies, that allow the identification of inconsistent instantiations (also called nogoods). Two main families of consistencies have been introduced so far: those that permit us to reason from variables such as (i, j)-consistency and those that permit us to reason from constraints such as relational (i, j)-consistency. This paper introduces a new family of consistencies based on the concept of failed value (a value pruned during search). This family is orthogonal to previous ones.