It is well-recognized that in the presence of singular (and in particular nonisolated) solutions of unconstrained or constrained smooth nonlinear equations, the existence of critical solutions has a crucial impact on the behavior of various Newton-type methods. On the one hand, it has been...

<Para ID="Par1">In these comments on the excellent survey paper by Izmailov and Solodov, we briefly discuss the main issues of critical Lagrange multipliers discovered and analyzed by the authors and then formulate some topics of interest for the future research. The latter topics concern the study of a...</para>

This paper concerns optimization and equilibrium problems with the so-called equilibrium constraints mathematical programs with equilibrium constraint (MPEC) and equilibrium problems with equilibrium constraint (EPEC), which frequently appear in applications to operations research. These classes...