Editing Mathematical optimization (section)

=== Feasibility problem ===
The ''[[satisfiability problem]]'', also called the ''feasibility problem'', is just the problem of finding any [[feasible solution]] at all without regard to objective value. This can be regarded as the special case of mathematical optimization where the objective value is the same for every solution, and thus any solution is optimal.

Many optimization algorithms need to start from a feasible point. One way to obtain such a point is to [[Relaxation (approximation)|relax]] the feasibility conditions using a [[slack variable]]; with enough slack, any starting point is feasible. Then, minimize that slack variable until the slack is null or negative.