Let S = S(R n) be the Schwartz space of all rapidly decreasing C 1 functions. All function spaces that occur here are deened on R n. Therefore, we omit the suux R n in S(R n) as well as in the other spaces below. Let D be the space of all compactly supported C 1 functions equipped with the usual topology. By S 0 and D 0 we denote the strong topological dual spaces of S and D, respectively. For ...