Symmetry Breaking in Soft CSPs

Exploiting symmetry in constraint satisfaction problems has become a very popular topic of research in recent times. The existence of symmetry in a problem has the effect of artificially increasing the size of the search space that is explored by search algorithms. Another significant topic of research has been approaches to reasoning about preferences. As constraint processing applications are becoming more widespread in areas such as electronic commerce, configuration, etc., it is becoming increasingly important that we can reason about preferences as efficiently as possible. We present an approach to dealing with symmetry in the semiring framework for soft constraints. We demonstrate that breaking symmetries in soft constraint satisfaction problems improves the efficiency of search. The paper contributes to the state-of-the-art in symmetry breaking, as well as in reasoning about preferences.

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