Kerodon

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

Remark 6.3.7.11. Let $S$ and $T$ be nonsingular simplicial sets. Then the join $S \star T$ is nonsingular. In particular, if $S$ is nonsingular, then the cone $S^{\triangleright }$ is also nonsingular.