Let \((X,\mathcal {M})\) be a measurable space and \(\mu \) and \(\nu \) be two finite measures on \((X,\mathcal {M})\). Show that the following are equivalent
- \(\nu \ll \mu \)
- Whenever \(A_1,\ldots \in \mathcal {M}\) satisfy \(\lim _{n\to \infty }\mu (A_n)=0\) we have \(\lim _{n\to \infty }\nu (A_n)=0\).