Global Constraint Catalog, 2nd Edition

This report presents a catalogue of global constraints where each constraint is explicitly described in terms of graph properties and/or automata and/or first order logical formulae with arithmetic. When available, it also presents some typical usage as well as some pointers to existing filtering algorithms

Global Constraint Catalog, 2nd Edition (revision a)

This report presents a catalogue of global constraints where each constraint is explicitly described in terms of graph properties and/or automata and/or first order logical formulae with arithmetic. When available, it also presents some typical usage as well as some pointers to existing filtering algorithms

A domain consistency algorithm for the stretch constraint

Abstract. The stretch constraint occurs in many rostering problems that arise in the industrial and public service sectors. In this paper we present an efficient algorithm for domain consistency propagation of the stretch constraint. Using benchmark and random instances, we show that this stronger consistency sometimes enables our propagator to solve more difficult problems than a previously proposed propagation algorithm for the stretch constraint. We also discuss variations of the stretch constraint that seem simple and useful, but turn out to be intractable to fully propagate.

Consistency Propagation for Stretch Constraints

I hereby declare that I am the sole author of this thesis. I authorize the University of Waterloo to lend this thesis to other institutions or individuals for the purpose of scholarly research. I further authorize the University of Waterloo to reproduce this thesis by photocopying or by other means, in total or in part, at the request of other institutions or individuals for the purpose of scholarly research. ii Scheduling and rostering problems are among the most common applications of constraint programming. In this thesis, we explore several global constraints for rostering problems. We demonstrate algorithms for efficiently enforcing domain consistency for these constraints, and show empirically that achieving this strongest possible level of consistency is not only of theoretical interest, but also has substantial value in practical applications. The focus of the thesis is a domain consistency algorithm for the stretch constraint based on dynamic programming. We also present an incremental version that sometime