Domain views for constraint programming

Abstract

Traditional constraint-programming systems provide the concept of variable views which implement a view of the type y∈=∈f(x) by delegating operations on variable y to variable x. While the traditional support is limited to bound consistency, this paper offers views that support domain consistency without any limitations. This paper proposes the alternative concept of domain views which delegate all domain operations. Domain views preserve the benefits of variable views, simplify the implementation of value-based propagation, and also support non-injective views compositionally. Experimental results demonstrate the practical benefits of domain views. The paper also reveals a subtle interaction between views and the exploitation of constraint idempotence, which may lead to incomplete propagation. © 2014 Springer International Publishing Switzerland.