# Definition:Wholly Real/Abbreviated Notation

Let $z = a + i b$ be a complex number such that $b = 0$.
That is, let $z$ be wholly real: $z = a + 0 i$, or $\tuple {a, 0}$
Despite the fact that $z$ is still a complex number, it is commonplace to use the same notation as if it were a real number, and hence say $z = a$.