Lemma 35.14.2. The property $\mathcal{P}(S) =$“$S$ is Cohen-Macaulay” is local in the syntomic topology.

Proof. This is clear from Lemma 35.14.1 above since a scheme is Cohen-Macaulay if and only if it is locally Noetherian and $(S_ k)$ for all $k \geq 0$, see Properties, Lemma 28.12.3. $\square$

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