$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
10.25
\begin{equation} \begin{gathered}\label{equation:realization-not-image} \xymatrix@C =50pt@R=50pt{ & | C_{\bullet } | \ar [dr]^{i} & \\ X \ar [ur]^{q} \ar [rr]^{f} & & Y } \end{gathered} \end{equation}