Definition:Scope of Connective/Definition 2

Definition
Let $\LL_0$ be the language of propositional logic.

Let $\circ$ be a connective of $\LL_0$.

Let $\mathbf W$ be a well-formed formula of $\LL_0$.

The scope of an occurrence of $\circ$ in $\mathbf W$ is defined as:
 * the set of statements that it connects, whether simple or compound.

The arity of $\circ$ determines the cardinality of this set.

In the case of a unary connective, there will be only one such statement.

Also see

 * Definition:Main Connective