Nonuniform Boolean constraint satisfaction problems with cardinality constraint
Nadia Creignou, Henning Schnoor, Ilka Schnoor · ACM Transactions on Computational Logic · 2010
We study the computational complexity of Boolean constraint satisfaction problems with cardinality constraint. A Galois connection between clones and coclones has received a lot of attention in the context of complexity considerations for constraint satisfaction problems. This connection does not seem to help when considering constraint satisfaction problems that support in addition a cardinality constraint. We prove that a similar Galois connection, involving a weaker closure operator and partial polymorphisms, can be applied to such problems. Thus, we establish dichotomies for the decision as well as for the counting problems in Schaefer's framework.