Definition 7.37.2. Let $\mathcal{C}$ be a site. Let $p, p'$ be points of $\mathcal{C}$ given by functors $u, u' : \mathcal{C} \to \textit{Sets}$. A morphism $f : p \to p'$ is given by a transformation of functors

$f_ u : u' \to u.$

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