Kerodon

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

Exercise 1.4.4.8. Let $\operatorname{\mathcal{C}}$ be a category and let $T$ be the collection of all monomorphisms in $\operatorname{\mathcal{C}}$. Show that $T$ is closed under retracts.