Definition:Apotome

Definition
Let $a, b \in \set {x \in \R_{>0} : x^2 \in \Q}$ be two rationally expressible numbers such that $a > b$.

Then $a - b$ is an apotome :
 * $(1): \quad \dfrac a b \notin \Q$
 * $(2): \quad \paren {\dfrac a b}^2 \in \Q$

where $\Q$ denotes the set of rational numbers.

Also see

 * Definition:Binomial (Euclidean)
 * Apotome is Irrational