cP(t)=I+∫A(yt,tt 两边取范数,就可用上述公式。,事实上 oD(t, to)=I+A(to(t, to )dt 叫∫A()ip(t)t(t,t ) I A(t) (t,t )dt t t 0 0 0  = +   两边取范数，就可用上述公式。，事实上 I A(t) (t, t ) dt (t, t ) I A(t) (t, t )dt 0 t t t t 0 0 0 0  +   = +   