... Preface The existence theorems, including theorems about various points like fixed points, coincidence points, intersection points, maximal elements, and other results as KKM theorems, minimax theorems, ... theory of existence theorems in mathematical analysis, including theorems on intersections, coincidence points, maximal elements, sectional points, and alternative theorems, KKM type theorems ... that existence theorems have many applications to problems in optimization, but, more interesting, some results about the solution existence in optimization were proved equivalent to certain existence...