Introduction to algorithms
A filtering algorithm for constraints of difference in CSPs
AAAI '94 Proceedings of the twelfth national conference on Artificial intelligence (vol. 1)
Revisiting the Cardinality Operator and Introducing the Cardinality-Path Constraint Family
Proceedings of the 17th International Conference on Logic Programming
Global Constraints for Lexicographic Orderings
CP '02 Proceedings of the 8th International Conference on Principles and Practice of Constraint Programming
Constraint Processing
Artificial Intelligence - Special issue: Distributed constraint satisfaction
Handbook of Constraint Programming (Foundations of Artificial Intelligence)
Handbook of Constraint Programming (Foundations of Artificial Intelligence)
SLIDE: A Useful Special Case of the CARDPATH Constraint
Proceedings of the 2008 conference on ECAI 2008: 18th European Conference on Artificial Intelligence
Encodings of the SEQUENCE constraint
CP'07 Proceedings of the 13th international conference on Principles and practice of constraint programming
Generalized arc consistency for global cardinality constraint
AAAI'96 Proceedings of the thirteenth national conference on Artificial intelligence - Volume 1
The theory of grammar constraints
CP'06 Proceedings of the 12th international conference on Principles and Practice of Constraint Programming
CP'06 Proceedings of the 12th international conference on Principles and Practice of Constraint Programming
Fast and flexible difference constraint propagation for DPLL(T)
SAT'06 Proceedings of the 9th international conference on Theory and Applications of Satisfiability Testing
Open constraints in a closed world
CPAIOR'06 Proceedings of the Third international conference on Integration of AI and OR Techniques in Constraint Programming for Combinatorial Optimization Problems
Open Constraints in a Boundable World
CPAIOR '09 Proceedings of the 6th International Conference on Integration of AI and OR Techniques in Constraint Programming for Combinatorial Optimization Problems
SOGgy constraints: soft open global constraints
CP'09 Proceedings of the 15th international conference on Principles and practice of constraint programming
Global constraints in distributed constraint satisfaction
Proceedings of the 11th International Conference on Autonomous Agents and Multiagent Systems - Volume 3
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Open forms of global constraints allow the addition of new variables to an argument during the execution of a constraint program. Such forms are needed for difficult constraint programming problems where problem construction and problem solving are interleaved. However, in general, filtering that is sound for a global constraint can be unsound when the constraint is open. This paper provides a simple characterization, called contractibility, of the constraints where filtering remains sound when the constraint is open. With this characterization we can easily determine whether a constraint is contractible or not. In the latter case, we can use it to derive the strongest contractible approximation to the constraint. We demonstrate how specific algorithms for some closed contractible constraints are easily adapted to open constraints.