Theorem pm2.24i

Description: Inference associated with pm2.24 . Its associated inference is pm2.24ii . (Contributed by NM, 20-Aug-2001)

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

Proof

Step	Hyp	Ref	Expression
1		pm2.24i.1	$$⊢\phi$$
2	1	a1i	$$⊢\neg \psi \to \phi$$
3	2	con1i	$$⊢\neg \phi \to \psi$$