CSP duality and trees of bounded pathwidth

• Published in: Theoretical computer science Vol. 411; no. 34; pp. 3188 - 3208
• Main Authors: Carvalho, Catarina, Dalmau, Víctor, Krokhin, Andrei
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 17.07.2010; Elsevier
• Subjects: Algebra; Applied sciences; Approximation; Bounded pathwidth; C (programming language); Combinatorics; Combinatorics. Ordered structures; Computer science; control theory; systems; Constraint satisfaction problem; Datalog; Exact sciences and technology; Games; Graph theory; Homomorphism duality; Homomorphisms; Mathematics; Miscellaneous; Nonlinearity; Polymorphisms; Sciences and techniques of general use; Searching; Theoretical computing; Trees; Constraint satisfaction problem; Homomorphism duality; Datalog; Polymorphisms; Bounded pathwidth; Hypergraph; Computer theory; Linearity; Tree; Duality; DATALOG; Homomorphism; Polymorphism

We study non-uniform constraint satisfaction problems definable in monadic Datalog stratified by the use of non-linearity. We show how such problems can be described in terms of homomorphism dualities involving trees of bounded pathwidth and in algebraic terms. For this, we introduce a new parameter...