T1 = Z1^2 T2 = T1*Z1 T1 = T1*X2 T2 = T2*Y2 T1 = T1-X1 T2 = T2-Y1 Z3 = Z1*T1 T3 = T1^2 T4 = T3*T1 T3 = T3*X1 T1 = 2*T3 X3 = T2^2 X3 = X3-T1 X3 = X3-T4 T3 = T3-X3 T3 = T3*T2 T4 = T4*Y1 Y3 = T3-T4