\begin{definition}[Definition:Represented by Quadratic Form]
Let $R$ be an integral domain.
Let $M$ be an $R$-module.
Let $q : M \to R$ be a quadratic form.
Let $a\in R$.
Then '''$q$ represents $a$ (over $R$)''' {{Iff}} there exists $x\in M\setminus\{0\}$ with $q(x) = a$.
\end{definition}