Let $M = (X, \mathcal{F}, \mu)$ be a D1158: Measure space such that
Let $\lambda \in [0, \infty]$ be an D5237: Unsigned basic number.
(i) | $f : X \to [0, \infty]$ is an D5610: Unsigned basic Borel function on $M$ |
Then
\begin{equation}
\lambda \mu(f > \lambda)
\leq \int_X f I_{\{ f > \lambda \}} \, d \mu
\end{equation}