Definition:Limit Inferior of Sequence of Sets/Notation

Definition
Let $\set {E_n: n \in \N}$ be a sequence of sets.

The limit inferior of $E_n$ can also be seen denoted as:
 * $\ds \underset {n \mathop \to \infty} {\underline \lim} E_n$

but this notation is not used on.

Some sources merely present this as:
 * $\ds \underline \lim E_n$