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