U1 = X1*Z2 U2 = X2*Z1 S1 = Y1*Z2 S2 = Y2*Z1 ZZ = Z1*Z2 T = U1+U2 M = S1+S2 t0 = T^2 t1 = ZZ^2 t2 = a*t1 t3 = U1*U2 t4 = t0-t3 R = t4+t2 F = ZZ*M L = M*F G = T*L t5 = R^2 W = t5-G t6 = F*W X3 = 2*t6 t7 = 2*W t8 = G-t7 t9 = L^2 t10 = R*t8 Y3 = t10-t9 t11 = F^2 t12 = F*t11 Z3 = 2*t12