Spaces with a Finite Family of Basic Functions

A space X is finite dimensional, locally compact and separable metrizable if and only if X has a finite basic family: continuous functions Phi_1,…,Phi_n of X to the reals, R, such that for all continuous f from X to R there are g_1,…, g_n in C® satisfying f(x)=g_1(Phi_1(x))+g_2(Phi_2(x))+…+g_n(Phi_n(x)) for all x in X. This give the complete solution to four problems on basic functions posed by Sternfeld, as well as questions posed by Hattori and others.