U1 = X1*ZZ2 U2 = X2*ZZ1 S1 = Y1*ZZZ2 S2 = Y2*ZZZ1 P = U2-U1 R = S2-S1 PP = P^2 PPP = P*PP Q = U1*PP t0 = R^2 t1 = 2*Q t2 = t0-PPP X3 = t2-t1 t3 = Q-X3 t4 = S1*PPP t5 = R*t3 Y3 = t5-t4 t6 = ZZ2*PP ZZ3 = ZZ1*t6 t7 = ZZZ2*PPP ZZZ3 = ZZZ1*t7