Proof by Contradiction/Variant 3

Theorem

Formulation 1

$p \implies \neg p \vdash \neg p$

Formulation 2

$\vdash \paren {p \implies \neg p} \implies \neg p$

This article is issued from ProofWiki. The text is available under Creative Commons Attribution-ShareAlike License unless otherwise noted. Additional terms may apply for the media files.