\begin{definition}[Definition:Logical Not/Truth Function]
The logical not connective defines the truth function $f^\neg$ as follows:
{{begin-eqn}}
{{eqn | l = \map {f^\neg} \F
      | r = \T
}}
{{eqn | l = \map {f^\neg} \T
      | r = \F
}}
{{end-eqn}}
\end{definition}