A = XX1^2
B = Y1^2
t0 = X1+Y1
t1 = t0^2
t2 = XX1+B
X3 = t2-t1
Z3 = A-1
XX3 = X3^2
ZZ3 = Z3^2
T3 = XX3+ZZ3
t3 = 2*XX1
t4 = A+t3
t5 = t4+1
t6 = B*t5
t7 = 2*t6
Y3 = t7-T3