XZ1 = X1*Z1
t0 = XZ1+Y1
U1 = t0^2
U2 = Y1^2
t1 = X1^2
V1 = t1^2
S1 = XZ1^2
aS1 = a2*S1
t2 = U2-V1
T = t2-aS1
t3 = U1-U2
X3 = t3-S1
t4 = 2*S1
t5 = T+V1
t6 = U2+aS1
t7 = t4^2
t8 = t5*t6
Y3 = t8+t7
Z3 = T-V1