Metamath Proof Explorer


Theorem r19.27vOLD

Description: Obsolete version of r19.27v as of 17-Jun-2023. (Contributed by NM, 3-Jun-2004) (Proof shortened by Andrew Salmon, 30-May-2011) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Assertion r19.27vOLD x A φ ψ x A φ ψ

Proof

Step Hyp Ref Expression
1 ax-1 ψ x A ψ
2 1 ralrimiv ψ x A ψ
3 2 anim2i x A φ ψ x A φ x A ψ
4 r19.26 x A φ ψ x A φ x A ψ
5 3 4 sylibr x A φ ψ x A φ ψ