SLIDE: A Useful Special Case of the CARDPATH Constraint

Christian Bessiere (1) , Emmanuel Hébrard (2) , Brahim Hnich (3) , Zeynep Kiziltan (4) , Toby Walsh (5)

1 COCONUT - Agents, Apprentissage, Contraintes
2 4C UCC - Cork Constraint Computation Centre
3 IUE - Izmir University of Economics
4 UNIBO - Alma Mater Studiorum Università di Bologna = University of Bologna
5 NICTA - National ICT Australia [Sydney]

We study the CARDPATH constraint. This ensures a given constraint holds a number of times down a sequence of variables. We show that SLIDE, a special case of CARDPATH where the slid constraint must hold always, can be used to encode a wide range of sliding sequence constraints including CARDPATH itself. We con- sider how to propagate SLIDE and provide a complete propagator for CARDPATH. Since propagation is NP-hard in general, we identify special cases where propagation takes polynomial time. Our experi- ments demonstrate that using SLIDE to encode global constraints can be as efficient and effective as specialised propagators.

Domaines: Intelligence artificielle [cs.AI]

Christian Bessiere, Emmanuel Hébrard, Brahim Hnich, Zeynep Kiziltan, Toby Walsh. SLIDE: A Useful Special Case of the CARDPATH Constraint. ECAI: European Conference on Artificial Intelligence, Jul 2008, Patras, Greece. pp.475-479. ⟨lirmm-00329876⟩