In this paper the notion of restricted dissimilarity function is discussed and some general results are shown. The relation between the concepts of restricted dissimilarity function and penalty function is presented. A specific model of construction of penalty functions by means of a wide class of restricted dissimilarity functions based upon automorphisms of the unit interval is studied. A characterization theorem of the automorphisms which give rise to two-dimensional penalty functions is proposed. A generalization of the previous theorem to any dimension n > 2 is also provided. Finally, a not convex example of generator of penalty functions of arbitrary dimension is illustrated. 
Penalty functions based upon a general class of restricted dissimilarity functions