  For any $n \geq 1$, and any $f :\{-1,1\}^{n} \to \mathbb{R}$ we have $ \Re\,
\mathbb{E}\, (f + i\, |\nabla f|)^{3/2} \leq \Re\, (\mathbb{E}f)^{3/2}, $ where
$z^{3/2}$ for $z=x+iy$ is taken with principal branch and $\Re$ denotes the
real part.
