Metamath Proof Explorer


Theorem 4ralbii

Description: Inference adding four restricted universal quantifiers to both sides of an equivalence. (Contributed by Scott Fenton, 28-Feb-2025)

Ref Expression
Hypothesis 4ralbii.1 φ ψ
Assertion 4ralbii x A y B z C w D φ x A y B z C w D ψ

Proof

Step Hyp Ref Expression
1 4ralbii.1 φ ψ
2 1 ralbii w D φ w D ψ
3 2 3ralbii x A y B z C w D φ x A y B z C w D ψ