PW-CT: Extending Compact-Table to Enforce Pairwise Consistency on Table Constraints

  • Anthony SchneiderEmail author
  • Berthe Y. ChoueiryEmail author
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 11008)


The Compact-Table (CT) algorithm is the current state-of-the-art algorithm for enforcing Generalized Arc Consistency (GAC) on table constraints during search. Recently, algorithms for enforcing Pairwise Consistency (PWC), which is strictly stronger than GAC, were shown to be advantageous for solving difficult problems. However, PWC algorithms can be costly in terms of CPU time and memory consumption. As a result, their overhead may offset the savings of search-space reduction. In this paper, we introduce PW-CT, an algorithm that modifies CT to enforce full PWC. We show that PW-CT avoids the high memory requirements of prior PWC algorithms and significantly reduces the time required to enforce PWC.


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Authors and Affiliations

  1. 1.Constraint Systems LaboratoryUniversity of Nebraska-LincolnLincolnUSA

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