Metamath Proof Explorer


Theorem r19.26m

Description: Version of 19.26 and r19.26 with restricted quantifiers ranging over different classes. (Contributed by NM, 22-Feb-2004)

Ref Expression
Assertion r19.26m x x A φ x B ψ x A φ x B ψ

Proof

Step Hyp Ref Expression
1 19.26 x x A φ x B ψ x x A φ x x B ψ
2 df-ral x A φ x x A φ
3 df-ral x B ψ x x B ψ
4 2 3 anbi12i x A φ x B ψ x x A φ x x B ψ
5 1 4 bitr4i x x A φ x B ψ x A φ x B ψ