Asking the Metaquestions in Constraint Tractability

  title={Asking the Metaquestions in Constraint Tractability},
  author={Hubie Chen and Beno{\^i}t Larose},
  journal={ACM Trans. Comput. Theory},
The constraint satisfaction problem (CSP) involves deciding, given a set of variables and a set of constraints on the variables, whether or not there is an assignment to the variables satisfying all of the constraints. One formulation of the CSP is as the problem of deciding, given a pair (G ℍ) of relational structures, whether or not there is a homomorphism from the first structure to the second structure. The CSP is generally NP-hard; a common way to restrict this problem is to fix the second… 

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