Law of non-contradiction (LNC)
A tautology stating that, for every statement \(P\),
\(P\) and its negation \(\lnot P\) cannot be both true,
so
\begin{equation*} \forall P, \>\> \lnot ( P \land \lnot P ). \end{equation*}A tautology stating that, for every statement \(P\),
\(P\) and its negation \(\lnot P\) cannot be both true,
so
\begin{equation*} \forall P, \>\> \lnot ( P \land \lnot P ). \end{equation*}