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Abstract : |
Balanced incomplete block design generation is a standard combinatorial problem from design theory. Constraint programming has recently been applied to the problem using a mixture of binary and non-binary constraints, with special techniques for symmetry breaking. We describe a new binary constraint model and apply search algorithms indirectly via satisability encoding. The encoded problems turn out to be hard for current algorithms, and symmetry breaking sometimes makes them harder, but the results suggest a promising direct approach. 1, |
