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Example (The Monodromy Representation). Let $f: X \rightarrow S$ be a covering map of topological spaces. Then $\operatorname{Sing}_{\bullet }(\pi ): \operatorname{Sing}_{\bullet }(X) \rightarrow \operatorname{Sing}_{\bullet }(S)$ is a covering map of simplicial sets (Proposition Applying Construction to $\operatorname{Sing}_{\bullet }(\pi )$, we obtain a functor from the fundamental groupoid $\pi _{\leq 1}(S)$ to the category of sets, which we will denote by $\operatorname{Tr}_{X/S}: \pi _{\leq 1}(S) \rightarrow \operatorname{Set}$ and refer to as the monodromy representation of $f$. Concretely, it is given on objects by the formula $\operatorname{Tr}_{X/S}(s) = \{ s\} \times _{S} X$.