Polymorphisms of Small Digraphs
نویسندگان
چکیده
For each digraph with at most 5 vertices, we provide a list of its polymorphisms interesting with respect to the complexity of the corresponding Constraint Satisfaction Problem. We find a digraph on six vertices such that the complexity of its retraction problem is unknown with current techniques; this is the smallest such example. AMS Mathematics Subject Classification (2000): 05C85, 68R10, 08A70
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تاریخ انتشار 2010