Let $M = (X, \mathcal{F})$ be a D1108: Measurable space.
Let $\mu : \mathcal{F} \to [0, \infty]$ be a D85: Unsigned basic measure on $M$ such that

(i)	$\mu(X) < \infty$

Then \begin{equation} \mu(\mathcal{F}) \subseteq [0, \mu(X)] \end{equation}