A = 0 1 1 1 0 1 1 1 0
H = a0 a1 a2 b0 b1 b2 c0 c1 c2
A*H = (b0+c0, b1+c1, b2+c2) (a0+c0, a1+c1, a2+c2) (a0+b0, a1+b1, a2+b2)
(nn).(nd)=(nd) AHW， (nd)(dd)=(n*d)
