Metamath Proof Explorer


Theorem riotabidva

Description: Equivalent wff's yield equal restricted class abstractions (deduction form). ( rabbidva analog.) (Contributed by NM, 17-Jan-2012)

Ref Expression
Hypothesis riotabidva.1 φxAψχ
Assertion riotabidva φιxA|ψ=ιxA|χ

Proof

Step Hyp Ref Expression
1 riotabidva.1 φxAψχ
2 1 pm5.32da φxAψxAχ
3 2 iotabidv φιx|xAψ=ιx|xAχ
4 df-riota ιxA|ψ=ιx|xAψ
5 df-riota ιxA|χ=ιx|xAχ
6 3 4 5 3eqtr4g φιxA|ψ=ιxA|χ