Set of symbols
Alphabet
Deduction system
Theory
Zermelo-Fraenkel set theory
Set
Subset
Power set
Hyperpower set sequence
Hyperpower set
Hypersubset
Subset algebra
Boolean algebra
Sigma-algebra
Bottom sigma-algebra
Empty sigma-algebra
Formulation 0
Let $\emptyset$ be the D13: Empty set.
A D11: Set $\mathcal{F} \subseteq \mathcal{P}(\emptyset)$ is an empty sigma-algebra on $\emptyset$ if and only if \begin{equation} \mathcal{F} = \{ \emptyset \} \end{equation}