t = mp_mul(t, t, h); e[0].exp = t = mpbarrett_reduce(&b, t, t);
h = mp_mul(h, s->r, h); e[1].exp = h = mpbarrett_reduce(&b, h, h);
w = G_CREATE(g); G_MEXP(g, w, e, 2);
t = mp_mul(t, t, h); e[0].exp = t = mpbarrett_reduce(&b, t, t);
h = mp_mul(h, s->r, h); e[1].exp = h = mpbarrett_reduce(&b, h, h);
w = G_CREATE(g); G_MEXP(g, w, e, 2);