Particular Point Space is not Weakly Countably Compact/Mistake
Jump to navigation
Jump to search
Source Work
1978: Lynn Arthur Steen and J. Arthur Seebach, Jr.: Counterexamples in Topology (2nd ed.):
- Part $\text {II}$: Counterexamples
- Section $8 \text { - } 10$: Particular Point Topology
- Item $12$
- Section $8 \text { - } 10$: Particular Point Topology
Mistake
- [A particular point space] $X$ is not weakly countably compact since any set which does not contain $p$ has no limit points.
However, this is true only of an infinite particular point space.
By definition, a space $X$ is weakly countably compact if and only if every infinite subset of $X$ has a limit point in $X$.
But a finite particular point space has no infinite subset.
So a finite particular point space is weakly countably compact vacuously.
Also see
Sources
- 1978: Lynn Arthur Steen and J. Arthur Seebach, Jr.: Counterexamples in Topology (2nd ed.) ... (previous) ... (next): Part $\text {II}$: Counterexamples: $8 \text { - } 10$. Particular Point Topology: $12$