# Definition:Basis (Topology)/Analytic Basis/Definition 2

## Definition

Let $\left({S, \tau}\right)$ be a topological space.

Let $\mathcal B \subseteq \tau$.

Then $\mathcal B$ is an analytic basis for $\tau$ if and only if:

$\forall U \in \tau: \forall x \in U: \exists V \in \mathcal B: x \in V \subseteq U$

## Also see

• Results about analytic bases can be found here.