$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
11.17
\begin{equation} \begin{gathered}\label{equation:Hom-functoriality} \xymatrix@R =50pt@C=50pt{ & \underline{ \Delta ^{0} }_{ \operatorname{Tw}(\operatorname{\mathcal{C}}) } \ar [dl]_-{ [\alpha ] } \ar [dr]^-{ [\beta ]} \\ \mathscr {H}_{\operatorname{\mathcal{C}}}|_{ \operatorname{Tw}(\operatorname{\mathcal{C}}) } \ar [rr]^{ [\gamma ] } & & \mathscr {H}_{\operatorname{\mathcal{D}}}|_{ \operatorname{Tw}(\operatorname{\mathcal{C}}) } } \end{gathered} \end{equation}