Metamath Proof Explorer


Theorem axio

Description: Definition of 'or' (intuitionistic logic axiom ax-io). (Contributed by Jim Kingdon, 21-May-2018) (New usage is discouraged.)

Ref Expression
Assertion axio ⊢ φ ∨ χ → ψ ↔ φ → ψ ∧ χ → ψ

Proof

Step Hyp Ref Expression
1 jaob ⊢ φ ∨ χ → ψ ↔ φ → ψ ∧ χ → ψ