Metamath Proof Explorer


Theorem axi5r

Description: Converse of axc4 (intuitionistic logic axiom ax-i5r). (Contributed by Jim Kingdon, 31-Dec-2017)

Ref Expression
Assertion axi5r x φ x ψ x x φ ψ

Proof

Step Hyp Ref Expression
1 hba1 x φ x x φ
2 hba1 x ψ x x ψ
3 1 2 hbim x φ x ψ x x φ x ψ
4 sp x ψ ψ
5 4 imim2i x φ x ψ x φ ψ
6 3 5 alrimih x φ x ψ x x φ ψ