source 2009.04.01 Lange appliesto jacobian-0 compute A = X1^2 compute B = Y1^2 compute C = B^2 compute D = 2 ((X1 + B)^2 - A - C) compute E = 3 A compute F = E^2 compute X3 = F - 2 D compute Y3 = E (D - X3) - 8 C compute Z3 = 2 Y1 Z1