source 2009.04.01 Bernstein--Lange
unified
compute ZZ1 = Z1^2
compute ZZ2 = Z2^2
compute U1 = X1 ZZ2
compute U2 = X2 ZZ1
compute S1 = Y1 Z2 ZZ2
compute S2 = Y2 Z1 ZZ1
compute H = U2-U1
compute I = (2 H)^2
compute J = H I
compute r = 2(S2-S1)
compute V = U1 I
compute X3 = r^2-J-2 V
compute Y3 = r(V-X3)-2 S1 J
compute Z3 = ((Z1+Z2)^2-ZZ1-ZZ2) H
compute ZZ3 = Z3^2
compute T3 = a ZZ3^2
