Characterizing tractable CSPs
In this paper, we introduce the notion of ω-graph as a representative graph for the hypergraph associated with general constraint satisfaction problems (CSPs) and define a new form of consistency called ω-consistency. We identify relationships between the structural property of the ω-graph and the level of ω-consistency that are sufficient to ensure tractability of general CSPs and we prove that the class of tractable CSPs identified here contains the class of tractable CSPs identified with some related conditions reported previously.
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