ThmDex – An index of mathematical definitions, results, and conjectures.
Result R4266 on D76: Set intersection
Countable set intersection with empty set is empty
Formulation 0
Let $\emptyset$ be the D13: Empty set.
Let $X_n$ be a D11: Set for each $n \in \mathbb{N}$ such that
(i) \begin{equation} \exists \, n \in \mathbb{N} : X_n = \emptyset \end{equation}
Then \begin{equation} \bigcap_{n \in \mathbb{N}} X_n = \emptyset \end{equation}