### 3.7.117. Heuristics

A constraint that was introduced for expressing a heuristics or a constraint ($\mathrm{𝚊𝚕𝚕𝚍𝚒𝚏𝚏𝚎𝚛𝚎𝚗𝚝}$) for which an algorithm that evaluate the number of solutions was proposed.

Remark: when we do not have good bounds on the cost variable of a constrained optimisation problem, skewed binary search was introduced in [SellmannKadioglu08] in order to take advantage of the fact that it is usually easier to improve the current solution cost's than to prove that a problem is not feasible.