Metamath Proof Explorer


Theorem rabbidva2

Description: Equivalent wff's yield equal restricted class abstractions. (Contributed by Thierry Arnoux, 4-Feb-2017)

Ref Expression
Hypothesis rabbidva2.1 φxAψxBχ
Assertion rabbidva2 φxA|ψ=xB|χ

Proof

Step Hyp Ref Expression
1 rabbidva2.1 φxAψxBχ
2 1 abbidv φx|xAψ=x|xBχ
3 df-rab xA|ψ=x|xAψ
4 df-rab xB|χ=x|xBχ
5 2 3 4 3eqtr4g φxA|ψ=xB|χ