Definition:Positive

Let $$\left({R, +, \circ; \le}\right)$$ 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:

$$\mathbf {Define:} \ R_+ \ \stackrel {\mathbf {def}} {==} \ \left\{{x \in R: 0 \le x}\right\}$$