Variable elimination in binary CSPs

Martin Cooper (1, 2) , Achref El Mouelhi (3) , Cyril Terrioux (4)

1 IRIT-ADRIA - Argumentation, Décision, Raisonnement, Incertitude et Apprentissage
2 UT3 - Université Toulouse III - Paul Sabatier
3 AUTRES
4 COALA - COntraintes, ALgorithmes et Applications

We investigate rules which allow variable elimination in binary CSP (constraint satisfaction problem) instances while conserving satisfiability. We study variable-elimination rules based on the language of forbidden patterns enriched with counting and quantification over variables and values. We propose new rules and compare them, both theoretically and experimentally. We give optimised algorithms to apply these rules and show that each define a novel tractable class. Using our variable-elimination rules in preprocessing allowed us to solve more benchmark problems than without.

Domains: Computer Science [cs]; Artificial Intelligence [cs.AI]

Martin Cooper, Achref El Mouelhi, Cyril Terrioux. Variable elimination in binary CSPs. 2019. ⟨hal-02142769⟩