\begin{definition}[Definition:Biconditional/Semantics of Biconditional/Necessary and Sufficient]
Let:
:$p \iff q$
where $\iff$ denotes the biconditional operator.
Then it can be said that '''$p$ is ''necessary and sufficient'' for $q$.'''
This is a consequence of the definitions of necessary and sufficient conditions.
\end{definition}