Let $M = (X, d)$ be a D1107: Metric space such that
(i) | $x : \mathbb{N} \to X$ is a D65: Cauchy sequence in $M$ |
Then
\begin{equation}
\exists \, a \in X, r > 0 :
x(\mathbb{N}) \subseteq B(a, r)
\end{equation}