“…Moreover, there is a q-deformation of the cup product in H * (H/I, Z) such that the usual cup product corresponds to the value q = 1, whereas the new product 0 corresponds to the value q = 0 (cf. [BK,§6] Proof. From the definition of 0 , to prove the lemma, it suffices to show that for any u, v, w ∈ Aff 2 (W ) such that c w u,v = 0 in the decomposition (1) following Theorem 2.2, we have…”