Set of Reciprocals of Positive Integers is Nowhere Dense in Reals

Theorem
Let $N$ be the set defined as:
 * $N := \set {\dfrac 1 n: n \in \Z_{>0} }$

where $\Z_{>0}$ is the set of (strictly) positive integers.

Let $\R$ denote the real number line with the usual (Euclidean) metric.

Then $N$ is nowhere dense in $\R$.

Proof
From Zero is Limit Point of Integer Reciprocal Space, the only limit point of $N$ is $0$.

Hence:
 * $\map \cl N = \set {\dfrac 1 n: n \in \Z_{>0} } \cup \set 0$

where $\map \cl N$ denotes the closure of $N$ in $\R$.

Trivially, $\map \cl N$ contains no open real intervals.

Hence no subset of $\map \cl N$ is open in $\R$.

Hence the union of all the subset of $\map \cl N$ which are open in $\R$ is empty.

That is, by definition, the interior of $N$ is empty.

That is:
 * $\paren {\map \cl N}^\circ = \O$

and the result follows by definition of nowhere dense.