Metamath Proof Explorer


Theorem bj-gabeqd

Description: Equality of generalized class abstractions. Deduction form. (Contributed by BJ, 4-Oct-2024)

Ref Expression
Hypotheses bj-gabeqd.nf ⊢ ( 𝜑 → ∀ 𝑥 𝜑 )
bj-gabeqd.c ⊢ ( 𝜑 → 𝐴 = 𝐵 )
bj-gabeqd.f ⊢ ( 𝜑 → ( 𝜓 ↔ 𝜒 ) )
Assertion bj-gabeqd ( 𝜑 → { 𝐴 ∣ 𝑥 ∣ 𝜓 } = { 𝐵 ∣ 𝑥 ∣ 𝜒 } )

Proof

Step Hyp Ref Expression
1 bj-gabeqd.nf ⊢ ( 𝜑 → ∀ 𝑥 𝜑 )
2 bj-gabeqd.c ⊢ ( 𝜑 → 𝐴 = 𝐵 )
3 bj-gabeqd.f ⊢ ( 𝜑 → ( 𝜓 ↔ 𝜒 ) )
4 3 biimpd ⊢ ( 𝜑 → ( 𝜓 → 𝜒 ) )
5 1 2 4 bj-gabssd ⊢ ( 𝜑 → { 𝐴 ∣ 𝑥 ∣ 𝜓 } ⊆ { 𝐵 ∣ 𝑥 ∣ 𝜒 } )
6 2 eqcomd ⊢ ( 𝜑 → 𝐵 = 𝐴 )
7 3 biimprd ⊢ ( 𝜑 → ( 𝜒 → 𝜓 ) )
8 1 6 7 bj-gabssd ⊢ ( 𝜑 → { 𝐵 ∣ 𝑥 ∣ 𝜒 } ⊆ { 𝐴 ∣ 𝑥 ∣ 𝜓 } )
9 5 8 eqssd ⊢ ( 𝜑 → { 𝐴 ∣ 𝑥 ∣ 𝜓 } = { 𝐵 ∣ 𝑥 ∣ 𝜒 } )