---
tag: 05006AJ7DZ
kind: concept
name: Tautology
msc: [03B05]
sources:
  - url: https://en.wikipedia.org/wiki/Tautology_(logic)
    locator: lead section
same_as:
  wikidata: Q209555
  wikipedia: Tautology (logic)
---

## Summary

A tautology is a formula of [[propositional logic|09K9MWD2QQ]] that is true for every assignment of truth values to its variables.