Abstract
The study of constraint satisfaction problems (CSPs) definable in various fragments of Datalog has recently gained considerable importance.We consider CSPs that are definable in the smallest natural recursive fragment of Datalog—monadic linear Datalog with at most one EDB (extensional database predicates) per rule, and also in the smallest nonlinear extension of this fragment. We give combinatorial and algebraic characterizations of such problems, in terms of homomorphism dualities and lattice operations, respectively.We then apply our results to study graph H-colouring problems.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
