C = X1*X2 D = Y1*Y2 t0 = C*D E = d*t0 t1 = X1+Y1 t2 = X2+Y2 t3 = t1*t2 t4 = 1-E t5 = t3-C t6 = t5-D X3 = t4*t6 t7 = a*C t8 = 1+E t9 = D-t7 Y3 = t8*t9 t10 = E^2 Z3 = 1-t10