Metamath Proof Explorer


Theorem ralbidv2

Description: Formula-building rule for restricted universal quantifier (deduction form). (Contributed by NM, 6-Apr-1997)

Ref Expression
Hypothesis ralbidv2.1 ( 𝜑 → ( ( 𝑥𝐴𝜓 ) ↔ ( 𝑥𝐵𝜒 ) ) )
Assertion ralbidv2 ( 𝜑 → ( ∀ 𝑥𝐴 𝜓 ↔ ∀ 𝑥𝐵 𝜒 ) )

Proof

Step Hyp Ref Expression
1 ralbidv2.1 ( 𝜑 → ( ( 𝑥𝐴𝜓 ) ↔ ( 𝑥𝐵𝜒 ) ) )
2 1 albidv ( 𝜑 → ( ∀ 𝑥 ( 𝑥𝐴𝜓 ) ↔ ∀ 𝑥 ( 𝑥𝐵𝜒 ) ) )
3 df-ral ( ∀ 𝑥𝐴 𝜓 ↔ ∀ 𝑥 ( 𝑥𝐴𝜓 ) )
4 df-ral ( ∀ 𝑥𝐵 𝜒 ↔ ∀ 𝑥 ( 𝑥𝐵𝜒 ) )
5 2 3 4 3bitr4g ( 𝜑 → ( ∀ 𝑥𝐴 𝜓 ↔ ∀ 𝑥𝐵 𝜒 ) )