Arens-Fort Space is Not Countably Compact
From ProofWiki
Theorem
Let $T = \left({S, \tau}\right)$ be the Arens-Fort space.
Then $T$ is not a countably compact space.
Proof
Let's give a proof by contradiction:
Assume that the Arens-Fort space is countably compact.
From Arens-Fort Space is Lindelöf, it is also Lindelöf.
Thus; from Countably Compact Lindelöf Space is Compact, it is concluded that $T$ is compact.
But from Arens-Fort Space is Not Compact we reach a contradiction.
$\blacksquare$
Sources
- Lynn Arthur Steen and J. Arthur Seebach, Jr.: Counterexamples in Topology (1970)... (previous)... (next): $\text{II}: \ 26: \ 4$