“…When the constraint q v ≤ q vs itself depends on the solution T , the authors are led to introduce and handle a system of equations and inequations involving a so-called quasi-variational inequality for which they prove the existence of solutions using penalization techniques. Penalization has been introduced by R. Courant [19] and it is very common in Optimization Theory (see e.g., [15] and [53]). For general results on (quasi-)variational inequalities and their utilization in economics, mechanics and physics, see among a vast literature [12,2,6,7,5,8,9,4,22,23,26,41,36,38,44,47,50,49,48].…”