Evaluation-based semiring meta-constraints

Abstract

Classical constraint satisfaction problems (CSPs) provide an expressive formalism for describing and solving many real-world problems. However, classical CSPs prove to be restrictive in situations where uncertainty, fuzziness, probability or optimisation are intrinsic. Soft constraints alleviate many of the restrictions which classical constraint satisfaction impose; in particular, soft constraints provide a basis for capturing notions such as vagueness, uncertainty and cost into the CSP model. We focus on the semiring-based approach to soft constraints. In this paper we present a new evaluation-based scheme for implementing meta-constraints, which can be applied to any existing implementation to improve its run-time performance.