$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
3.71
\begin{equation} \begin{gathered}\label{equation:connective-vs-reduced} \xymatrix@R =50pt@C=50pt{ E \ar [r]^-{g'} \ar [d] & \widetilde{X} \ar [d]^{q} \\ \Delta ^0 \ar [r] & Y. } \end{gathered} \end{equation}