Excluded Point Space is Ultraconnected
Jump to navigation
Jump to search
Theorem
Let $T = \left({S, \tau_{\bar p}}\right)$ be an excluded point space.
Then $T$ is ultraconnected.
Proof 1
- Excluded Point Topology is Open Extension Topology of Discrete Topology
- Open Extension Space is Ultraconnected
$\blacksquare$
Proof 2
Apart from $S$, every open set of $T$ does not contain $p$, by definition of excluded point space.
So, apart from $\O$, every closed set of $T$ does contain $p$, by definition of closed set.
So every pair of closed sets of $T$ has an intersection which contains at least $p$.
So there are no non-empty disjoint closed sets of $T$.
Hence the result, by definition of ultraconnected.
$\blacksquare$