Definition:Limit Point/Topology

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

Limit Point of Point
The concept of a limit point can be sharpened to apply to individual points, as follows:

Examples

 * $0$ is the only limit point of the set $\set {\dfrac 1 n: n \in \N}$ in the usual (Euclidean) topology of $\R$.


 * Every point of $\R$ is a limit point of $\R$ in the usual (Euclidean) topology.


 * From Rationals are Everywhere Dense in Topological Space of Reals, it is shown that any point $x \in \R$ is a limit point of the set of rational numbers $\Q$. This is an interesting case, because $\Q$ is countable but its set of limit points in $\R$ is $\R$ itself, which is uncountable.


 * The set $\Z$ has no limit points in the usual (Euclidean) topology of $\R$.

Also

 * Equivalence of Definitions of Limit Point


 * Definition:Condensation Point
 * Definition:Omega-Accumulation Point
 * Definition:Adherent Point


 * Relationship between Limit Point Types