T1 = Z1^2 T2 = T1*Z1 T1 = T1*X2 T2 = T2*Y2 T1 = X1-T1 T2 = T2-Y1 Z3 = Z1*T1 T4 = T1^2 T1 = T1*T4 T4 = T4*X1 X3 = T2^2 X3 = X3+T1 Y3 = T1*Y1 T1 = 2*T4 X3 = X3-T1 T4 = X3-T4 T4 = T4*T2 Y3 = T4-Y3