Lemma 18.34.5. Let \mathcal{C} be a site. Let \mathcal{O}_1 \to \mathcal{O}_2 be a homomorphism of presheaves of rings. Let \mathcal{F} be a presheaf of \mathcal{O}_2-modules. Then \mathcal{P}^ k_{\mathcal{O}_2^\# /\mathcal{O}_1^\# }(\mathcal{F}^\# ) is the sheaf associated to the presheaf U \mapsto P^ k_{\mathcal{O}_2(U)/\mathcal{O}_1(U)}(\mathcal{F}(U)).
Proof. This can be proved in exactly the same way as is done for the sheaf of differentials in Lemma 18.33.4. Perhaps a more pleasing approach is to use the universal property of Lemma 18.34.3 directly to see the equality. We omit the details. \square
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