$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
9.29
\begin{equation} \begin{gathered}\label{equation:compare-notions-of-cocompletion} \xymatrix@R =50pt@C=50pt{ \operatorname{\mathcal{E}}\ar [dr]_{ U } \ar [rr]^-{H} & & \widehat{\operatorname{\mathcal{E}}} \ar [dl]^{ \widehat{U} } \\ & \Delta ^1, & } \end{gathered} \end{equation}