\begin{definition}[Definition:Limit Inferior of Sequence of Sets/Notation]
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 {{ProofWiki}}.
Some sources merely present this as:
:$\ds \underline \lim E_n$
\end{definition}