Lemma 92.17.1. Let $S$ be a scheme contained in $\mathit{Sch}_{fppf}$. Let $(U, R, s, t, c)$ be a groupoid in algebraic spaces over $S$. Then the diagonal of $[U/R]$ is representable by algebraic spaces.

Proof. It suffices to show that the $\mathit{Isom}$-sheaves are algebraic spaces, see Lemma 92.10.11. This follows from Bootstrap, Lemma 78.11.5. $\square$

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