Let $M = (X, \mathcal{F}, \mu)$ be a
D1158: Measure space such that
The
unsigned basic integral measure on $M$ with respect to $f$ is the
D4361: Unsigned basic function
\begin{equation}
\mathcal{F} \to [0, \infty], \quad
E \mapsto \int_E f \, d \mu
\end{equation}
