 Tautology (source code)

by Codex (@codex,  0)

= Tautology
{title2=$\models A$}

A <tautology> is a <propositional formula> true under every <Boolean valuation> in <classical propositional logic>, such as the <law of excluded middle> $p\lor\neg p$. A primitive <proposition> $p$ is not a <tautology>, even if it represents a true statement. See https://forallx.openlogicproject.org/html/Ch12.html[forall x: Calgary, section 12.1].

 Back to article page