\begin{definition}[Definition:Logical Connective/Unary]
A '''unary logical connective''' (or '''one-place connective''') is a connective whose effect on its compound statement is determined by the truth value of ''one'' substatement.
In standard Aristotelian logic, there are four of these.
The only non-trivial one is logical not, as shown on Unary Truth Functions.
\end{definition}