$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
5.38
\begin{equation} \label{equation:slice-interior-fibration-cartesian} \begin{gathered} \xymatrix@R =50pt@C=50pt{ \{ 1\} \ar [r]^-{\sigma _0} \ar [d] & \operatorname{\mathcal{C}}_{/f} \ar [d]^-{q} \\ \Delta ^{1} \ar [r]^-{\overline{\sigma }} \ar@ {-->}[ur]^{\sigma } & \operatorname{\mathcal{C}}_{/f_0} } \end{gathered} \end{equation}