Definition:Scope of Occurrence

Definition
Let $\FF$ be a formal language with alphabet $\AA$.

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

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

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

Also see

 * Definition:Scope (Logic), highlighting two of the most common usages of scopes