Z1Squared = Z1^2
U2 = Z1Squared * X2
Z1Cubed = Z1Squared * Z1
S2 = Z1Cubed * Y2
Z2Squared = Z2^2
U1 = Z2Squared * X1
Z2Cubed = Z2Squared * Z2
S1 = Z2Cubed * Y1
H = U1 - U2
R = S1 - S2
HSquared = H^2
G = HSquared * H
V = HSquared * U1
t0 = 2 * V
t1 = R^2
t2 = t1 + G
X3 = t2 - t0
t3 = V - X3
t4 = G * S1
t5 = t3 * R
Y3 = t5 - t4
Z3 = H * Z1
Z3 = Z3 * Z2
Z3Squared = Z3^2
W = Z3Squared^2
T3 = W * a