Let $(X, \mathcal{A},\mu)$ be a measure space, and let $A_1,A_2,...\in \mathcal{A}$. Assume that $\sum_{j=1}^\infty \mu(A_j)<\infty.$ I have already proved following statements:
(1) $n \cdot \mu (\bigcap_{j=1}^\infty A_j)\leq \sum_{j=1}^\infty \mu(A_j) $
(2) $\lim_{n\to \infty} \mu (\bigcap_{j=1}^\infty A_j)=0$
(3) $ \mu (\bigcap_{j=1}^\infty A_j)=0$
I need to prove that if we set
$ E=\bigcap_{j=1}^\infty (\bigcup_{k=n}^\infty A_k)$
then i follows that $ \mu(E)=0$.
Can anyone help med with this problem.
No comments:
Post a Comment