Theorem bj-pm2.01i

Description: Inference associated with the weak Clavius law pm2.01 . (Contributed by BJ, 30-Mar-2020)

	Ref	Expression
Hypothesis	bj-pm2.01i.1	$$⊢\phi \to \neg \phi$$
Assertion	bj-pm2.01i	$$⊢\neg \phi$$

Proof

Step	Hyp	Ref	Expression
1		bj-pm2.01i.1	$$⊢\phi \to \neg \phi$$
2		pm2.01	$$⊢\left(\phi \to \neg \phi \right)\to \neg \phi$$
3	1 2	ax-mp	$$⊢\neg \phi$$