A
D1106: Topological space $T = (X, \mathcal{T})$ is a
Baire topological space if and only if
\begin{equation}
\forall \, U_0, U_1, U_2, \dots \in \mathcal{T} \, (\forall \, n \in \mathbb{N} : \mathsf{closure}(U_n) = X \quad \implies \quad \mathsf{closure} \Bigg( \bigcap_{n \in \mathbb{N}} U_n \Bigg) = X)
\end{equation}