\begin{definition}[Definition:Positive]
Let $\struct {R, +, \circ, \le}$ be an ordered ring whose zero is $0_R$.
Then $x \in R$ is '''positive''' {{iff}} $0_R \le x$.
The set of all '''positive elements of $R$''' is denoted:
:$R_{\ge 0_R} := \set {x \in R: 0_R \le x}$
\end{definition}