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ECAI
2004
Springer

Symmetry Breaking as a Prelude to Implied Constraints: A Constraint Modelling Pattern

14 years 4 months ago
Symmetry Breaking as a Prelude to Implied Constraints: A Constraint Modelling Pattern
Finite-domain constraint programming can be used to solve a wide range of problems by first modelling the problem as a set of constraints that characterise the problem’s solutions, then searching for solutions that satisfy the constraints. Experts often augment models with implied constraints and constraints that break symmetries in the model. An emerging pattern in the modelling process, highlighted and demonstrated here, is that some powerful implied constraints can be derived only after symmetry-breaking constraints have been added. Furthermore, the choice between alternative symmetry-breaking constraints is commonly made by considering either the amount of symmetry broken or the strength of pruning obtained in comparison with the overhead of enforcing the constraints. We demonstrate that the choice should also consider the strength of the implied constraints derivable from the symmetry breaking constraints. We also discuss future automation of the selection of symmetry-breaking ...
Alan M. Frisch, Christopher Jefferson, Ian Miguel
Added 01 Jul 2010
Updated 01 Jul 2010
Type Conference
Year 2004
Where ECAI
Authors Alan M. Frisch, Christopher Jefferson, Ian Miguel
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