Product of Positive Element and Element Greater than One
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Theorem
Let $\struct {R, +, \circ, \le}$ be an ordered ring with unity $1_R$ and zero $0_R$.
Let $x, y \in R$.
Suppose that $x > 0_R$ and $y > 1_R$.
Then $x \circ y > x$ and $y \circ x > x$.
Proof
\(\ds y\) | \(>\) | \(\ds 1_R\) | ||||||||||||
\(\ds x \circ y\) | \(>\) | \(\ds x \circ 1_R\) | $x > 0_R$, Properties of Ordered Ring: $(6)$ | |||||||||||
\(\ds x \circ y\) | \(>\) | \(\ds x\) | Definition of Unity of Ring |
A similar argument shows that $y \circ x > x$.
$\blacksquare$