# Definition:Ternary Notation

Ternary notation is the technique of expressing numbers in base $3$.
That is, every number $x \in \R$ is expressed in the form:
$\displaystyle x = \sum_{j \mathop \in \Z} r_j 3^j$
where $\forall j \in \Z: r_j \in \left\{{0, 1, 2}\right\}$.