Corollary 1.5.5.13. Let $X$ be a contractible Kan complex. Then $X$ is a Kan complex. In particular, $X$ is an $\infty $-category.
$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
Corollary 1.5.5.13. Let $X$ be a contractible Kan complex. Then $X$ is a Kan complex. In particular, $X$ is an $\infty $-category.