$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
7.28
\begin{equation} \begin{gathered}\label{equation:relative-Kan-extension-mapping} \xymatrix@R =50pt@C=50pt{ \operatorname{\partial \Delta }^ n \ar [r]^-{ \sigma _0 } \ar [d] & \operatorname{Fun}(\operatorname{\mathcal{C}}, \operatorname{\mathcal{D}}) \ar [d]^{V} \\ \Delta ^ n \ar@ {-->}[ur] \ar [r] & \operatorname{Fun}(\operatorname{\mathcal{C}}^{0}, \operatorname{\mathcal{D}}) \times _{ \operatorname{Fun}(\operatorname{\mathcal{C}}^{0}, \operatorname{\mathcal{E}}) } \operatorname{Fun}( \operatorname{\mathcal{C}}, \operatorname{\mathcal{E}}) } \end{gathered} \end{equation}