# Definition:Positive/Rational Number

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## Definition

The **positive rational numbers** are the set defined as:

- $\Q_{\ge 0} := \set {x \in \Q: x \ge 0}$

That is, all the rational numbers that are greater than or equal to zero.

## Also known as

In order to remove all confusion as to whether **positive rational number** is intended to mean **strictly positive rational number**, the use of the term **non-negative rational number** is often recommended instead.

The $\mathsf{Pr} \infty \mathsf{fWiki}$-specific notation $\Q_{\ge 0}$ is actually non-standard. The conventional symbols to denote this concept are $\Q_+$ and $\Q^+$, but these can be confused with the set $\set {x \in \Q: x > 0}$.