Perfect Hashing and CNF Encodings of Cardinality Constraints
We study the problem of encoding cardinality constraints (threshold functions) on Boolean variables into CNF. Specifically, we propose new encodings based on (perfect) hashing that are efficient in terms of the number of clauses, auxiliary variables, and propagation strength. We compare the properties of our encodings to known ones, and provide experimental results evaluating their practical effectiveness.
KeywordsHash Function Auxiliary Variable Boolean Variable Conjunctive Normal Form Cardinality Constraint
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