Exists Integer Below Any Real Number
From ProofWiki
Theorem
Let $x$ be a real number.
Then there exists an integer less than $x$:
- $\forall x \in \R: \exists n \in \Z: n < x$
Proof
Clearly we may assume without loss of generality that $x < 0$.
From the Archimedean Principle:
- $\exists m \in \N: m > -x$
By Field of Real Numbers, we have that $\R$ is a totally ordered field.
Therefore by property $(3)$ of Properties of Totally Ordered Fields, $\Z \owns -m < x$.
$\blacksquare$