u = Y2-Y1 uu = u^2 v = X2-X1 vv = v^2 vvv = v*vv R = vv*X1 t0 = 2*R t1 = uu-vvv A = t1-t0 X3 = v*A t2 = R-A t3 = vvv*Y1 t4 = u*t2 Y3 = t4-t3 Z3 = vvv