iX2 = i*X2 C2 = Y2+iX2 D2 = Y2-iX2 iX1 = i*X1 C1 = Y1+iX1 D1 = Y1-iX1 A = Z1*Z2 t0 = A^2 B = 2*t0 C = C1*C2 D = D1*D2 L = D+C M = Y1*Y2 t1 = 2*M N = t1-L t2 = M*N E = d*t2 F = B-E G = B+E t3 = D-C t4 = F*t3 t5 = A*t4 X3 = i*t5 t6 = G*L Y3 = A*t6 t7 = G*F Z3 = c*t7