Category:Tautology

This category contains results about Tautology in the context of propositional logic.
Definitions specific to this category can be found in Definitions/Tautology.

A tautology is a statement which is always true, independently of any relevant circumstances that could theoretically influence its truth value.

It is epitomised by the statement form:

$p \implies p$

that is:

if $p$ is true then $p$ is true.

An example of a "relevant circumstance" here is the truth value of $p$.

The archetypal tautology is symbolised by $\top$, and referred to as Top.