Let $M = (\Omega, \mathcal{F})$ be a D1108: Measurable space.
Let $\mathbb{P} : \mathcal{F} \to [0, \infty]$ be a D198: Probability measure on $M$.
Let $\mathbb{P} : \mathcal{F} \to [0, \infty]$ be a D198: Probability measure on $M$.
Then
\begin{equation}
\mathbb{P}(\mathcal{F}) \subseteq [0, 1]
\end{equation}