  In our previous paper [International Journal of Theoretical Physics, 41
(2002), 1165-1190] we have shown, following the tradition of synthetic
differential geometry, that div and rot are uniquely determined, so long as we
require that the divergence theorem and the Stokes theorem should hold on the
infinitesimal level. In this paper we will simplify the discussion considerably
in terms of differential forms, leading to the natural derivation of exterior
differentiation in the usual form.
