Let $M = (X, \mathcal{F}, \mu)$ be a D1158: Measure space such that

(i) | $E, F \in \mathcal{F}$ are each a D1109: Measurable set in $M$ |

(ii) | $E \subseteq F$ is a D78: Subset of $F$ |

(iii) | \begin{equation} \mu(E) < \infty \end{equation} |

Then
\begin{equation}
\mu(F \setminus E) = \mu(F) - \mu(E)
\end{equation}