Kerodon

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

Example 3.1.1.4. Let $q: X \rightarrow S$ be a morphism of simplicial sets which induces an isomorphism from $X$ to a summand of $S$ (Definition 1.1.6.1). Then $q$ is a Kan fibration.