t0 = Z1^2 t1 = Z2^2 t2 = 1/t0 t3 = 1/t1 t4 = Y2*t3 t5 = Y1*t2 A = t5-t4 t6 = 1/Z1 t7 = 1/Z2 t8 = X2*t7 t9 = X1*t6 B = t9-t8 t10 = 1/Z1 t11 = X1*t10 t12 = B^2 D = t11*t12 t13 = 1/Z2 t14 = X2*t13 t15 = A^2 t16 = B^2 t17 = B^2 t18 = t14*t17 t19 = a*t16 t20 = t15-t19 t21 = t20-D X3 = t21-t18 t22 = Z1^2 t23 = 1/t22 t24 = Y1*t23 t25 = D-X3 t26 = B^4 t27 = t24*t26 t28 = B*t25 t29 = A*t28 Y3 = t29-t27 Z3 = B^2 ZZ3 = Z3^2