Metamath Proof Explorer


Theorem imorri

Description: Infer implication from disjunction. (Contributed by Jonathan Ben-Naim, 3-Jun-2011)

Ref Expression
Hypothesis imorri.1 ¬ φ ψ
Assertion imorri φ ψ

Proof

Step Hyp Ref Expression
1 imorri.1 ¬ φ ψ
2 imor φ ψ ¬ φ ψ
3 1 2 mpbir φ ψ