Let $A \subseteq B$ be commutative noetherian rings. I have found the following claim: **"Separability implies smoothness".** However, it seems to me that, at least with my definitions, this claim is false: If $A \subseteq B$ is separable, then (assuming the claim is true) $A \subseteq B$ is smooth, then by a result of Grothendieck, $A \subseteq B$ is flat, but this seems too much (especially in view of [Examples on pages 95-97][1] and [Corollary 9][2]). I will really appreciate if one can either post a sketch of proof/tell me where I can find a proof, or a counterexample. Actually, I have already posted this question [here][3], but got no comments thus far. [1]: http://link.springer.com/chapter/10.1007%2F978-94-015-8555-2_5 [2]: http://ac.els-cdn.com/0021869380902331/1-s2.0-0021869380902331-main.pdf?_tid=73b8ca36-2846-11e5-8b8e-00000aab0f6b&acdnat=1436672055_edd3c1b73a42fb02541d5db701287e09 [3]: http://math.stackexchange.com/questions/1358096/separability-implies-smoothness