Theorem pm2.24i 136

Description: Inference version of pm2.24 101. (Contributed by NM, 20-Aug-2001.)

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	. . 3 ⊢ φ
2	1	a1i 10	. 2 ⊢ (¬ ψ → φ)
3	2	con1i 121	1 ⊢ (¬ φ → ψ)

This proof depends on syntax axioms:  ¬ wn 3   → wi 4

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem is used by:  orci  379  niabn  917  ax12dgen1  1725