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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Comment #4517 by Manuel Hoff on
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