$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
4.42
\begin{equation} \begin{gathered}\label{equation:isofibrant-mapping-space} \xymatrix@R =50pt@C=50pt{ A \ar [r] \ar [d] & \operatorname{Hom}_{ \operatorname{Fun}(\operatorname{\mathcal{C}}, \operatorname{Set_{\Delta }}) }( \mathscr {E}, \mathscr {F})_{\bullet } \ar [d]^{\theta } \\ B \ar [r] \ar@ {-->}[ur] & \operatorname{Hom}_{ \operatorname{Fun}(\operatorname{\mathcal{C}}, \operatorname{Set_{\Delta }}) }( \mathscr {E}_0, \mathscr {F})_{\bullet } } \end{gathered} \end{equation}