New Algebraic Tools for Constraint Satisfaction

Abstract. The Galois connection involving polymorphisms and coclones has received a lot of attention in regard to constraint satisfaction problems. However, it fails if we are interested in a reduction giving equivalence instead of only satisfiability-equivalence. We show how a similar Galois connection involving weaker closure operators can be applied for these problems. As an example of the usefulness of our construction, we show how to obtain very short proofs of complexity classifications in this context. Keywords. computational complexity, constraints, partial polymorphisms

• Type: Conference
• Year: 2006
• Where: DAGSTUHL
• Authors: Henning Schnoor, Ilka Schnoor
• Keywords: Connection Involving Polymorphisms, Constraint Satisfaction Problems, DAGSTUHL 2006, DAGSTUHL 2007, Galois Connection