# Definition:Scope of Occurrence

## Definition

Let $\mathcal F$ be a formal language with alphabet $\mathcal A$.

Let $\mathbf A$ be a well-formed formula of $\mathcal F$.

Let $a$ be a fixed occurrence of some element of $\mathcal A$ in $\mathbf A$.

Then the scope of $a$ is the smallest well-formed part of $\mathbf A$ that contains $a$.