$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
10.24
\begin{equation} \begin{gathered}\label{equation:universal-property-of-image2} \xymatrix@R =50pt@C=50pt{ X \ar [r]^-{g} \ar [dr]^{f} & Y_1 \ar [d]^{i_1} \\ & Y } \end{gathered} \end{equation}