(i) | $f : X \to [0, \infty]$ is a D313: Measurable function on $M$ |

**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}