“…Due to the special structure of f (x), general-purpose nonsmooth methods ( [33,22,3]) may not be efficient to solve them. So, by exploiting their peculiar structure, a great deal of effort has been devoted to developing efficient methods for minimax problems, see, e.g., [37,6,31,23,41,25,38,39,9,14,15,10,11,7,12].…”