Definition:Closure/Normed Vector Space

Definition
Let $M = \struct {X, \norm{\, \cdot \,}}$ be a normed vector space.

Let $S \subseteq X$.

The closure of $S$ (in $M$) is the union of $S$ and $S'$, the set of all limit points of $S$:
 * $S^- := S \cup S'$