Underestimating the cost of a soft constraint is dangerous: revisiting the edit-distance based soft regular constraint

  title={Underestimating the cost of a soft constraint is dangerous: revisiting the edit-distance based soft regular constraint},
  author={Jun He and Pierre Flener and Justin Pearson},
  journal={Journal of Heuristics},
Many real-life problems are over-constrained, so that no solution satisfying all their constraints exists. Soft constraints, with costs denoting how much the constraints are violated, are used to solve these problems. We use the edit-distance based SoftRegular constraint as an example to show that a propagation algorithm that sometimes underestimates the cost may guide the search to incorrect (non-optimal) solutions to an over-constrained problem. To compute correctly the cost for the edit… 
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