A = Z1*Z2
t0 = A^2
B = d*t0
C = X1*X2
D = Y1*Y2
E = C*D
t1 = a*D
H = C-t1
t2 = X1+Y1
t3 = X2+Y2
t4 = t2*t3
t5 = t4-C
I = t5-D
t6 = E+B
X3 = t6*H
t7 = E-B
Y3 = t7*I
t8 = H*I
Z3 = A*t8