Let $X$ be a D11: Set.
A D11: Set $\mathcal{F} \subseteq \mathcal{P}(X)$ is a bottom sigma-algebra on $X$ if and only if
\begin{equation}
\mathcal{F} = \{ \emptyset, X \}
\end{equation}
▶ | Bottom measurable space |
▶ | Empty sigma-algebra |