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

(i)	$E \subseteq X$ is a D78: Subset of $X$

Then $E$ is a subnull set in $M$ if and only if there exists D1109: Measurable set $F \in \mathcal{F}$ such that

(1)	\begin{equation} E \subseteq F \end{equation}	(D78: Subset)
(2)	\begin{equation} \mu(F) = 0 \end{equation}	(D1676: Null measurable set)