Exact Penalty in Constrained Optimization and the Mordukhovich Basic Subdifferential

In this chapter, we use the penalty approach to study two constrained minimization problems in infinite-dimensional Asplund spaces. A penalty function is said to have the exact penalty property if there is a penalty coefficient for which a solution of an unconstrained penalized problem is a solution of the corresponding constrained problem. We use the notion of the Mordukhovich basic subdifferential and show that the exact penalty property is stable under perturbations of objective functions.