Kerodon

$\Newextarrow{\xRightarrow}{5,5}{0x21D2}$ $\newcommand\empty{}$
$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$

Example 3.4.2.12. Suppose we are given a pushout diagram of simplicial sets

3.49
\begin{equation} \label{diagram:homotopy-pushout-square9} \begin{gathered} \xymatrix@R =50pt@C=50pt{ A \ar [r]^-{f_0} \ar [d] & A_1 \ar [d] \\ A_1 \ar [r] & A_{01}. } \end{gathered} \end{equation}

If $f_0$ is a monomorphism, then (3.49) is also a homotopy pushout diagram.