Theorem wl-luk-pm2.24i

Description: Inference rule. Copy of pm2.24i with a different proof. (Contributed by Wolf Lammen, 17-Dec-2018) (New usage is discouraged.) (Proof modification is discouraged.)

	Ref	Expression
Hypothesis	wl-luk-pm2.24i.1	$$⊢\phi$$
Assertion	wl-luk-pm2.24i	$$⊢\neg \phi \to \psi$$

Proof

Step	Hyp	Ref	Expression
1		wl-luk-pm2.24i.1	$$⊢\phi$$
2		ax-luk3	$$⊢\phi \to \left(\neg \phi \to \psi \right)$$
3	1 2	ax-mp	$$⊢\neg \phi \to \psi$$