Kerodon

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

Remark 4.3.3.20. For every pair of simplicial sets $X$ and $Y$, we have a canonical isomorphism $(X \star Y)^{\operatorname{op}} \simeq Y^{\operatorname{op}} \star X^{\operatorname{op}}$.