Z3 = Y1*Z1
S = Y1^2
L = X1^2
L = 3*L
L = L/2
T = -S
T = T*X1
X3 = L^2
X3 = X3+T
X3 = X3+T
S = S^2
T = T+X3
Y3 = T*L
Y3 = Y3+S
Y3 = -Y3