Theorem orri 860

Description: Infer disjunction from implication. (Contributed by NM, 11-Jun-1994.)

Hypothesis

Ref	Expression
orri.1	⊢ (¬ 𝜑 → 𝜓)

Assertion

Ref	Expression
orri	⊢ (𝜑 ∨ 𝜓)

Proof of Theorem orri

Step	Hyp	Ref	Expression
1		orri.1	. 2 ⊢ (¬ 𝜑 → 𝜓)
2		df-or 846	. 2 ⊢ ((𝜑 ∨ 𝜓) ↔ (¬ 𝜑 → 𝜓))
3	1, 2	mpbir 234	1 ⊢ (𝜑 ∨ 𝜓)

Syntax hints:  ¬ wn 3   → wi 4   ∨ wo 845

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

This theorem depends on definitions:  df-bi 210  df-or 846

This theorem is referenced by:  orci  863  olci  864  pm2.25  888  curryax  892  exmid  893  pm2.13  896  pm5.11g  942  pm5.12  944  pm5.14  945  pm5.55  947  pm3.12  992  pm5.15  1011  pm5.54  1016  4exmid  1048  rb-ax2  1756  rb-ax3  1757  rb-ax4  1758  exmo  2560  axi12  2728  exmidne  2959  ifeqor  4464  fvbr0  6678  letrii  10788  clwwlknondisj  27980  poimirlem26  35348  tsbi3  35838  tsan2  35845  tsan3  35846  clsk1indlem2  41103