Dynamic Variable Elimination During Propagation Solving
2008 (English)In: PPDP 2008: Proceedings of the 10th International ACM SIGPLAN Symposium on Principles and Practice of Declarative Programming, ACM Press, 2008, 247-257 p.Conference paper (Refereed)
Constraint propagation solvers interleave propagation (removing impossible values from variables domains) with search. Propagation is performed by executing propagators (removing values) implementing constraints (defining impossible values). In order to specify constraint problems with a propagation solver often many new intermediate variables need to be introduced. Each variable plays a role in calculating the value of some expression. But as search proceeds not all of these expressions will be of interest any longer, but the propagators implementing them will remain active. In this paper we show how we can analyse the propagation graph of the solver in linear time to determine intermediate variables that can be removed without effecting the result. Experiments show that applying this analysis can reduce the space and time requirements for constraint propagation on example problems.
Place, publisher, year, edition, pages
ACM Press, 2008. 247-257 p.
Analysis, Constraint (logic) programming, Constraint propagation, Redundancy
IdentifiersURN: urn:nbn:se:kth:diva-70427DOI: 10.1145/1389449.1389480ScopusID: 2-s2.0-57549101415OAI: oai:DiVA.org:kth-70427DiVA: diva2:486328
PPDP 2008: 10th International ACM SIGPLAN Symposium on Principles and Practice of Declarative Programming. Valencia. 15 July 2008 - 17 July 2008
QC 201201312012-01-302012-01-302012-01-31Bibliographically approved