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AMAI
2004
Springer

Combining Symmetry Breaking with Other Constraints: Lexicographic Ordering with Sums

14 years 5 months ago
Combining Symmetry Breaking with Other Constraints: Lexicographic Ordering with Sums
Abstract. We introduce a new global constraint which combines together the lexicographic ordering constraint with two sum constraints. Lexicographic ordering constraints are frequently used to break symmetry, whilst sum constraints occur in many problems involving capacity or partitioning. Our results show that this global constraint is useful when there is a very large space to explore, such as when the problem is unsatisfiable, or when the search strategy is poor or conflicts with the symmetry breaking constraints. By studying in detail when combining lexicographical ordering with other constraints is useful, we propose a new heuristic for deciding when to combine constraints together.
Brahim Hnich, Zeynep Kiziltan, Toby Walsh
Added 30 Jun 2010
Updated 30 Jun 2010
Type Conference
Year 2004
Where AMAI
Authors Brahim Hnich, Zeynep Kiziltan, Toby Walsh
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