isIsotropic -- determines whether a Grothendieck-Witt class is isotropic
Usage:
isIsotropic beta
Inputs:
beta, a Grothendieck-Witt Class, denoted by $\beta\in\text{GW}(k)$, where $k$ is $\mathbb{Q}$, $ \mathbb{R}$, $\mathbb{C}$, or a finite field of characteristic not 2