---
tag: TAQKQEGP19
kind: concept
name: Classical reductio ad absurdum
sources:
  - wikipedia: en:76765067@r1368301704
    locator: Glossary of logic, section C
    note: adopted
    mention: wikipedia://en/76765067#AMY3
    sections: [Summary]
inventory: [RZRRD407W9]
---

## Summary

A stronger form of [[reductio ad absurdum|0J0XBKG64S]], where instead of only deriving $\neg P$ from showing that $P$ leads to a contradiction, one can also derive $P$ from showing that $\neg P$ leads to a contradiction.