Definition:Neighborhood (Topology)

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

Neighborhood of a Point
The set $A$ can be a singleton, in which case the definition is of the neighborhood of a point.

Also see

 * Definition:Open Neighborhood
 * Definition:Closed Neighborhood


 * Topological Space is Open Neighborhood of Subset


 * Open Superset is Open Neighborhood


 * Set is Open iff Neighborhood of all its Points