Theorem pm2.24i 553

Description: Inference version of pm2.24 551. (Contributed by NM, 20-Aug-2001.) (Revised by Mario Carneiro, 31-Jan-2015.)

Hypothesis

Ref	Expression
pm2.24i.1	⊢ 𝜑

Assertion

Ref	Expression
pm2.24i	⊢ (¬ 𝜑 → 𝜓)

Proof of Theorem pm2.24i

Step	Hyp	Ref	Expression
1		pm2.24i.1	. 2 ⊢ 𝜑
2		pm2.21 547	. 2 ⊢ (¬ 𝜑 → (𝜑 → 𝜓))
3	1, 2	mpi 15	1 ⊢ (¬ 𝜑 → 𝜓)

Syntax hints:  ¬ wn 3   → wi 4

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-in2 545

This theorem is referenced by:  niabn  874