Consecutive Integers are Coprime/Proof 1

Theorem
$\forall h \in \Z$, $h$ and $h + 1$ have only two common factors, $1$ and $-1$.

That is, consecutive integers are always coprime.

Proof
$\gcd \left\{{h+1, h}\right\} = \gcd \left\{{h, 1}\right\} = \gcd \left\{{1, 0}\right\} = 1$ from the Euclidean Algorithm.