Theorem axin2 2698

Description: 'Not' elimination (intuitionistic logic axiom ax-in2). (Contributed by Jim Kingdon, 21-May-2018.) (New usage is discouraged.)

Assertion

Ref	Expression
axin2	⊢ (¬ 𝜑 → (𝜑 → 𝜓))

Proof of Theorem axin2

Step	Hyp	Ref	Expression
1		pm2.21 123	1 ⊢ (¬ 𝜑 → (𝜑 → 𝜓))

Syntax hints:  ¬ wn 3   → wi 4

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem is referenced by: (None)