“…If r = 1, for fl' to be inverse to fl, it is sufficient that ~0 annihilate terms in dz. Thus, we obtain a homomorphism (6) . Recall ~ : X ~ X o C C ~, and apply Lemma 13 to X 0 to find a holomorphie matrix ~¢ = (ai) defined on X o such that, for all yo ~ ~t (L), the hyperspaee No(yo) = {z; z = Yo + zC(Yo) v for v E C ~} form a normal field to X o -zt(L).…”