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 ( 𝜑 → ( ( 𝑥𝐴𝜓 ) ↔ ( 𝑥𝐵𝜒 ) ) )
Assertion rabbidva2 ( 𝜑 → { 𝑥𝐴𝜓 } = { 𝑥𝐵𝜒 } )

Proof

Step Hyp Ref Expression
1 rabbidva2.1 ( 𝜑 → ( ( 𝑥𝐴𝜓 ) ↔ ( 𝑥𝐵𝜒 ) ) )
2 1 abbidv ( 𝜑 → { 𝑥 ∣ ( 𝑥𝐴𝜓 ) } = { 𝑥 ∣ ( 𝑥𝐵𝜒 ) } )
3 df-rab { 𝑥𝐴𝜓 } = { 𝑥 ∣ ( 𝑥𝐴𝜓 ) }
4 df-rab { 𝑥𝐵𝜒 } = { 𝑥 ∣ ( 𝑥𝐵𝜒 ) }
5 2 3 4 3eqtr4g ( 𝜑 → { 𝑥𝐴𝜓 } = { 𝑥𝐵𝜒 } )