Let $X$ be a D11: Set such that
Let $p \in (0, \infty)$ be a D993: Real number.
(i) | $f : X \to [0, \infty]$ is an D4361: Unsigned basic function on $X$ |
Then
\begin{equation}
f(x)^p
= \int^{\infty}_0 I_{\{ f(x) > t \}}(x) p t^{p - 1} \, d t
\end{equation}