EXPLORING THE JUNGLE OF NONSMOOTH ANALYSIS
Jean‐Paul Penot · 2007
Nonsmooth functions are prevalent. Moreover, during the last decades a number of concepts have been introduced to deal with non di¤erentiable functions. Still, some classes of nonsmooth functions are of great interest in view of their stability properties and of the fact that their subdi¤erentials present some continuity or monotonicity properties. Such functions are characterized by some sorts of approximate convexity which form a full spectrum. Correspondingly, some classes of subsets can be delineated with similar features. Thus some form of unity is emerging in nonsmooth analysis.