“…Among the results of this note are a characterization of the function ε (x, y), more precisely a functional equations approach to ε (x, y), and, moreover, a similar approach to σ (x, y) (see Theorems 3,4,5,6). We furthermore deal with elliptic and spherical geometry on the basis of the distance notions (2), (3), respectively: points are defined, lines and hyperspheres, and the isometries of the geometries in question are determined.…”