Kerodon

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

Corollary 1.4.5.12. Let $X_{\bullet }$ be a contractible Kan complex. Then $X_{\bullet }$ is a Kan complex. In particular, $X_{\bullet }$ is an $\infty $-category.