$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
6.13
\begin{equation} \begin{gathered}\label{equation:proposition:cocartesian-fiberwise-localization} \xymatrix@R =50pt@C=50pt{ \operatorname{\mathcal{B}}'_{Y} \ar [r]^-{e^{\ast }} \ar [d]^{ G_{Y} } & \operatorname{\mathcal{B}}'_{X} \ar [d]^{ G_{X}} \\ \operatorname{\mathcal{B}}_{Y} \ar [r]^-{ e^{\ast } } & \operatorname{\mathcal{B}}_{X} } \end{gathered} \end{equation}