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Negative Constraints

A. Fernandez
E.T.S. de Ingenieria Informatica
Departamento de Lenguajes y Ciencias de la Computacion
Despacho 3.2.50
Universidad de Malaga
Teatinos s/n
29071-Malaga
Spain

Patricia M. Hill
School of Computing
The University of Leeds
Leeds LS2 9JT
England

Abstract:

In this paper we present a novel extension to the constraint logic programming on Finite Domains (clp(FD)) which combines the usual clp(FD) primitive constraint $X\ in\ range$ with a new primitive constraint $X\ notin\ range$. We show that, together, they are more expressive and provide better constraint propagation than having $X\ in\ range$ on its own. It is shown how the standard clp(FD) framework can be adapted to support this extension by defining conditions for the checking of the consistency of constraints and new methods for their propagation.