# Definition:Complement of Truth Function

Let $f: \Bbb B^k \to \Bbb B$ be a truth function.
The complement of $f$ is the function $f'$ defined by:
$f': \Bbb B^k \to \Bbb B, f' \left({p}\right) = \neg \left({f \left({p}\right)}\right)$
The complement of $f$ is sometimes written as $\overline f$.