Editing Constraint programming (section)

== Constraint optimization problem ==
{{Main|Constrained optimization}}
A constraint optimization problem (COP) is a constraint satisfaction problem associated to an objective function.

An ''optimal solution'' to a minimization (maximization) COP is a solution that minimizes (maximizes) the value of the ''objective function''. 

During the search of the solutions of a COP, a user can wish for:

* finding a solution (satisfying all the constraints);

* finding the best solution with respect to the objective;
* proving the optimality of the best found solution;
* proving the unsatisfiability of the problem.