$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
8.76
\begin{equation} \begin{gathered}\label{equation:compare-dagger-with-conjugacy} \xymatrix@C =50pt@R=50pt{ \operatorname{\mathcal{E}}^{\dagger } \times _{\operatorname{\mathcal{C}}^{\operatorname{op}} } \operatorname{Tw}(\operatorname{\mathcal{C}}) \ar [r]^-{T} \ar [d] & \operatorname{\mathcal{E}}\ar [d]^{ U } \\ \operatorname{Tw}(\operatorname{\mathcal{C}}) \ar [r] & \operatorname{\mathcal{C}}} \end{gathered} \end{equation}