Variational analysis is a well-recognized area of mathematics with many applications to optimization, control, equilibria, stability, machine learning, statistics, as well as to practical models of science and technology. The underlying feature of variational analysis is the broad usage of generalized differentiation, which allows us to deal with nonsmooth functions, sets with nonsmooth boundaries, and set-valued mappings. Such objects naturally and frequently appear not only in problems with nonsmooth initial data but mainly due to employing variational or extremal principles and techniques.
