Step 3: Let Solve 5=r,产=f(S,r,t) q(t)=s(t) s(to)=q(to),r(to)=q(to) (t)=r(t) However,there is no guarantee that g(t),q(t)satisfy Φ(q)=0 Φ，9=VStep 3: Let s  q, r  q Solve ( ) ( ), ( ) ( ) , ( , , ) 0 0 0 0 t t t t t s q r q s r r f s r        ( ) ( ) ( ) ( ) t t t t q r q s                  ( ) ( ) , ( ) ( ) ( ) ( ) 0 0 0 0 0 0 t t t t t t v u q v u q    However, there is no guarantee that q(t), q(t) satisfy (q)  0  qq V