On the classes of higher-order Jensen-convex functions and Wright-convex   functions
  The classes of n-Wright-convex functions and n-Jensen-convex functions are compared with each other. It is shown that for any odd natural number $n$ the first one is the proper subclass of the second one. To reach this aim new tools connected with measure theory are developed. 
Kazimierz Nikodem, Teresa Rajba, Szymon Wasowicz
math.CA math.PR