On the almost periodic functions in the sense of Levitan

In this note we present some theorems on the superposition of an $(N{V}_p)$-almost periodic (a.p. for short) function, a $\mu$-a.p. function and an $(N\mu )$-a.p. function. Moreover, we prove a theorem on the bounded primary function of an $(N{S}_p)$-a.p. function. Finally, we prove that the inverse of a $V_p$-a.p. function is $(N{V}_p)$-a.p.