Kerodon

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

Remark 4.1.5.8. Let $f: X \rightarrow Y$ and $g: Y \rightarrow Z$ be morphisms of simplicial sets. Suppose that $g$ is an inner covering map. Then $f$ is an inner covering map if and only if $g \circ f$ is an inner covering map. In particular, the collection of inner covering maps is closed under composition.