\begin{definition}[Definition:Rational Number/Fraction]
By definition, a rational number is a number which can be expressed in the form:
:$\dfrac a b$
where $a$ and $b$ are integers.
A '''fraction''' is a rational number such that, when expressed in canonical form $\dfrac a b$ (that is, such that $a$ and $b$ are coprime), the denominator $b$ is not $1$.
\end{definition}