  We give a new and self-contained proof of a generic version of the (former)
Helgason conjecture. It says that for generic spectral parameters the Poisson
transform is a topological isomorphism, with the inverse given by a boundary
value map. Following Oshima's approach to a simplified definition of boundary
values, and using the earlier work of Baouendi and Goulaouic on Fuchsian type
equations, our proof is along the lines of our earlier work in the rank one
distributional case, and works for both the hyperfunction and the distribution
setting.
