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The Stacks project

Lemma 15.81.6. Let R be a ring. Let R \to A be a finite type ring map. Let m \in \mathbf{Z}. Let (K^\bullet , L^\bullet , M^\bullet , f, g, h) be a distinguished triangle in D(A).

  1. If K^\bullet is (m + 1)-pseudo-coherent relative to R and L^\bullet is m-pseudo-coherent relative to R then M^\bullet is m-pseudo-coherent relative to R.

  2. If K^\bullet , M^\bullet are m-pseudo-coherent relative to R, then L^\bullet is m-pseudo-coherent relative to R.

  3. If L^\bullet is (m + 1)-pseudo-coherent relative to R and M^\bullet is m-pseudo-coherent relative to R, then K^\bullet is (m + 1)-pseudo-coherent relative to R.

Moreover, if two out of three of K^\bullet , L^\bullet , M^\bullet are pseudo-coherent relative to R, the so is the third.

Proof. Follows immediately from Lemma 15.64.2 and the definitions. \square


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