Metric Space is Fully Normal
From ProofWiki
Theorem
Let $M = \left({A, d}\right)$ be a metric space.
Then $M$ is a fully normal space.
Proof
We have that a metric space is fully $T_4$.
We also have that a metric space is a $T_1$ (Fréchet) space.
Hence the result, by definition of a fully normal space.
$\blacksquare$
Sources
- Lynn Arthur Steen and J. Arthur Seebach, Jr.: Counterexamples in Topology (1970)... (previous)... (next): $\text{I}: \ \S 5$