Enhancing Neighbourhood Substitutability Thanks to Singleton Arc Consistency

In this paper, a semantic generalization of neighbourhood substitutability is presented. Instead of the syntactical concept of supports, our generalization originally exploits a new semantic measure based on Single Arc-Consistency (SAC) checking. This generalization is then exploited in two different ways. Firstly, a new pretreatment of constraints networks is proposed. Secondly, as SAC is a basic operation in backtrack search-based algorithms like $\MAC$, we show that our generalization can be easily applied dynamically. The experimental results of our approach show interesting improvements on some classes of $\CSP$ instances and demonstrate the feasibility of the dynamic integration of our generalized neighbourhood substitutability.