[[Neighbourhood]]
# Neighbourhood system

Given a topological space $(X, \mathcal{T})$, the **neighbourhood system** $\mathcal{N}(x)$ of a point $x \in X$
is the set of [[Neighbourhood|neighbourhoods]] containing $x$. #m/def/topology 

- [[Neighbourhood basis]]

#
---
#state/tidy | #lang/en | #SemBr