  We explain the origin of the difficulties that appear in a straightforward
application of the QRPA in C(12), and we demonstrate that it is imperative to
use the projected QRPA (PQRPA). Satisfactory results, not only for the weak
processes among the ground states of the triad B(12),C(12),N(12), but also for
the inclusive ones are obtained. We sketch as well a new formalism for the
neutrino-nucleus interaction that furnishes very simple final formulae for the
muon capture rate and neutrino induced cross sections.
