Metamath Proof Explorer


Theorem hbim1

Description: A closed form of hbim . (Contributed by NM, 2-Jun-1993)

Ref Expression
Hypotheses hbim1.1 φ x φ
hbim1.2 φ ψ x ψ
Assertion hbim1 φ ψ x φ ψ

Proof

Step Hyp Ref Expression
1 hbim1.1 φ x φ
2 hbim1.2 φ ψ x ψ
3 2 a2i φ ψ φ x ψ
4 1 19.21h x φ ψ φ x ψ
5 3 4 sylibr φ ψ x φ ψ