Metamath Proof Explorer


Theorem rabbida3

Description: Equivalent wff's yield equal restricted class abstractions. (Contributed by Glauco Siliprandi, 23-Oct-2021)

Ref Expression
Hypotheses rabbida3.1 x φ
rabbida3.2 φ x A ψ x B χ
Assertion rabbida3 φ x A | ψ = x B | χ

Proof

Step Hyp Ref Expression
1 rabbida3.1 x φ
2 rabbida3.2 φ x A ψ x B χ
3 1 2 abbid φ x | x A ψ = x | x B χ
4 df-rab x A | ψ = x | x A ψ
5 df-rab x B | χ = x | x B χ
6 3 4 5 3eqtr4g φ x A | ψ = x B | χ