Lemma 92.8.4. The cotangent complex L_{B/A} is zero in each of the following cases:
A \to B and B \otimes _ A B \to B are flat, i.e., A \to B is weakly étale (More on Algebra, Definition 15.104.1),
A \to B is a flat epimorphism of rings,
B = S^{-1}A for some multiplicative subset S \subset A,
A \to B is unramified and flat,
A \to B is étale,
A \to B is a filtered colimit of ring maps for which the cotangent complex vanishes,
B is a henselization of a local ring of A,
B is a strict henselization of a local ring of A, and
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