The Stacks project

Lemma 34.3.18. Given schemes $X$, $Y$, $Z$ in $(\mathit{Sch}/S)_{Zar}$ and morphisms $f : X \to Y$, $g : Y \to Z$ we have $g_{big} \circ f_{big} = (g \circ f)_{big}$ and $g_{small} \circ f_{small} = (g \circ f)_{small}$.

Proof. This follows from the simple description of pushforward and pullback for the functors on the big sites from Lemma 34.3.16. For the functors on the small sites this is Sheaves, Lemma 6.21.2 via the identification of Lemma 34.3.12. $\square$

Comments (2)

Comment #7402 by Floris Ruijter on

"Given schemes X, Y, Y" should be "[..] X, Y, Z"

There are also:

  • 2 comment(s) on Section 34.3: The Zariski topology

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