Metamath Proof Explorer


Theorem jaoi2

Description: Inference removing a negated conjunct in a disjunction of an antecedent if this conjunct is part of the disjunction. (Contributed by Alexander van der Vekens, 3-Nov-2017) (Proof shortened by Wolf Lammen, 21-Sep-2018)

Ref Expression
Hypothesis jaoi2.1 ⊢ φ ∨ ¬ φ ∧ χ → ψ
Assertion jaoi2 ⊢ φ ∨ χ → ψ

Proof

Step Hyp Ref Expression
1 jaoi2.1 ⊢ φ ∨ ¬ φ ∧ χ → ψ
2 pm5.63 ⊢ φ ∨ χ ↔ φ ∨ ¬ φ ∧ χ
3 2 1 sylbi ⊢ φ ∨ χ → ψ