$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
5.1
\begin{equation} \label{equation:fibered-categories} \{ \textnormal{Functors $\mathscr {F}: \operatorname{\mathcal{C}}\rightarrow \mathbf{Cat}$} \} \simeq \{ \textnormal{Cocartesian fibrations $U: \operatorname{\mathcal{E}}\rightarrow \operatorname{\mathcal{C}}$} \} , \end{equation}