$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
3.47
\begin{equation} \label{diagram:homotopy-pushout-square1} \begin{gathered} \xymatrix@R =50pt@C=50pt{ A \ar [r]^-{f_0} \ar [d] & A_{0} \ar [d] \\ A_{1} \ar [r] & A_{01}, } \end{gathered} \end{equation}