$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
7.18
\begin{equation} \begin{gathered}\label{equation:existence-Kan-fiberwise} \xymatrix@R =50pt@C=50pt{ \operatorname{\mathcal{K}}\ar [r]^-{ F_0 } \ar [d] & \operatorname{\mathcal{D}}\ar [d]^{U} \\ \operatorname{\mathcal{K}}\star _{\operatorname{\mathcal{C}}} \operatorname{\mathcal{C}}\ar@ {-->}[ur]^{F} \ar [r] & \operatorname{\mathcal{E}}. } \end{gathered} \end{equation}