$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
7.80
\begin{equation} \begin{gathered}\label{equation:cartesian-transformation-cone-indexed} \xymatrix { \mathscr {F} \ar [r] \ar [d]^{\gamma } & \underline{C} \ar [d]^{ \underline{f} } \\ \mathscr {G} \ar [r] & \underline{D} } \end{gathered} \end{equation}