Let $E_j$ and $F_j$ each be a D11: Set for every $j \in J$ such that

(i)	\begin{equation} \forall \, j \in J : E_j \subseteq F_j \end{equation}

Then \begin{equation} \bigcup_{j \in J} E_j \subseteq \bigcup_{j \in J} F_j \end{equation}