The Stacks project

Lemma 83.5.6. Let $S$ be a scheme, and let $B$ be an algebraic space over $S$. Let $j : R \to U \times _ B U$ be a pre-relation over $B$. Then $j_\infty : R_\infty \to U \times _ B U$ is a pre-equivalence relation over $B$. Moreover

  1. $\phi : U \to X$ is $R$-invariant if and only if it is $R_\infty $-invariant,

  2. the canonical map of quotient sheaves $U/R \to U/R_\infty $ (see Groupoids in Spaces, Section 78.19) is an isomorphism,

  3. weak $R$-orbits agree with weak $R_\infty $-orbits,

  4. $R$-orbits agree with $R_\infty $-orbits,

  5. if $s, t$ are locally of finite type, then $s_\infty $, $t_\infty $ are locally of finite type,

  6. add more here as needed.

Proof. Omitted. Hint for (5): Any property of $s, t$ which is stable under composition and stable under base change, and Zariski local on the source will be inherited by $s_\infty , t_\infty $. $\square$


Comments (1)

Comment #212 by Rex on

Typo: "an ismorphism"


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