Theorem cbvoprab23davw

Description: Change the second and third bound variables in an operation abstraction. Deduction form. (Contributed by GG, 14-Aug-2025)

	Ref	Expression
Hypothesis	cbvoprab23davw.1	⊢ ( ( ( 𝜑 ∧ 𝑦 = 𝑤 ) ∧ 𝑧 = 𝑣 ) → ( 𝜓 ↔ 𝜒 ) )
Assertion	cbvoprab23davw	⊢ ( 𝜑 → { ⟨ ⟨ 𝑥 , 𝑦 ⟩ , 𝑧 ⟩ ∣ 𝜓 } = { ⟨ ⟨ 𝑥 , 𝑤 ⟩ , 𝑣 ⟩ ∣ 𝜒 } )

Proof

Step	Hyp	Ref	Expression
1		cbvoprab23davw.1	⊢ ( ( ( 𝜑 ∧ 𝑦 = 𝑤 ) ∧ 𝑧 = 𝑣 ) → ( 𝜓 ↔ 𝜒 ) )
2		eqidd	⊢ ( ( ( 𝜑 ∧ 𝑦 = 𝑤 ) ∧ 𝑧 = 𝑣 ) → 𝑥 = 𝑥 )
3		simplr	⊢ ( ( ( 𝜑 ∧ 𝑦 = 𝑤 ) ∧ 𝑧 = 𝑣 ) → 𝑦 = 𝑤 )
4	2 3	opeq12d	⊢ ( ( ( 𝜑 ∧ 𝑦 = 𝑤 ) ∧ 𝑧 = 𝑣 ) → ⟨ 𝑥 , 𝑦 ⟩ = ⟨ 𝑥 , 𝑤 ⟩ )
5		simpr	⊢ ( ( ( 𝜑 ∧ 𝑦 = 𝑤 ) ∧ 𝑧 = 𝑣 ) → 𝑧 = 𝑣 )
6	4 5	opeq12d	⊢ ( ( ( 𝜑 ∧ 𝑦 = 𝑤 ) ∧ 𝑧 = 𝑣 ) → ⟨ ⟨ 𝑥 , 𝑦 ⟩ , 𝑧 ⟩ = ⟨ ⟨ 𝑥 , 𝑤 ⟩ , 𝑣 ⟩ )
7	6	eqeq2d	⊢ ( ( ( 𝜑 ∧ 𝑦 = 𝑤 ) ∧ 𝑧 = 𝑣 ) → ( 𝑡 = ⟨ ⟨ 𝑥 , 𝑦 ⟩ , 𝑧 ⟩ ↔ 𝑡 = ⟨ ⟨ 𝑥 , 𝑤 ⟩ , 𝑣 ⟩ ) )
8	7 1	anbi12d	⊢ ( ( ( 𝜑 ∧ 𝑦 = 𝑤 ) ∧ 𝑧 = 𝑣 ) → ( ( 𝑡 = ⟨ ⟨ 𝑥 , 𝑦 ⟩ , 𝑧 ⟩ ∧ 𝜓 ) ↔ ( 𝑡 = ⟨ ⟨ 𝑥 , 𝑤 ⟩ , 𝑣 ⟩ ∧ 𝜒 ) ) )
9	8	cbvexdvaw	⊢ ( ( 𝜑 ∧ 𝑦 = 𝑤 ) → ( ∃ 𝑧 ( 𝑡 = ⟨ ⟨ 𝑥 , 𝑦 ⟩ , 𝑧 ⟩ ∧ 𝜓 ) ↔ ∃ 𝑣 ( 𝑡 = ⟨ ⟨ 𝑥 , 𝑤 ⟩ , 𝑣 ⟩ ∧ 𝜒 ) ) )
10	9	cbvexdvaw	⊢ ( 𝜑 → ( ∃ 𝑦 ∃ 𝑧 ( 𝑡 = ⟨ ⟨ 𝑥 , 𝑦 ⟩ , 𝑧 ⟩ ∧ 𝜓 ) ↔ ∃ 𝑤 ∃ 𝑣 ( 𝑡 = ⟨ ⟨ 𝑥 , 𝑤 ⟩ , 𝑣 ⟩ ∧ 𝜒 ) ) )
11	10	exbidv	⊢ ( 𝜑 → ( ∃ 𝑥 ∃ 𝑦 ∃ 𝑧 ( 𝑡 = ⟨ ⟨ 𝑥 , 𝑦 ⟩ , 𝑧 ⟩ ∧ 𝜓 ) ↔ ∃ 𝑥 ∃ 𝑤 ∃ 𝑣 ( 𝑡 = ⟨ ⟨ 𝑥 , 𝑤 ⟩ , 𝑣 ⟩ ∧ 𝜒 ) ) )
12	11	abbidv	⊢ ( 𝜑 → { 𝑡 ∣ ∃ 𝑥 ∃ 𝑦 ∃ 𝑧 ( 𝑡 = ⟨ ⟨ 𝑥 , 𝑦 ⟩ , 𝑧 ⟩ ∧ 𝜓 ) } = { 𝑡 ∣ ∃ 𝑥 ∃ 𝑤 ∃ 𝑣 ( 𝑡 = ⟨ ⟨ 𝑥 , 𝑤 ⟩ , 𝑣 ⟩ ∧ 𝜒 ) } )
13		df-oprab	⊢ { ⟨ ⟨ 𝑥 , 𝑦 ⟩ , 𝑧 ⟩ ∣ 𝜓 } = { 𝑡 ∣ ∃ 𝑥 ∃ 𝑦 ∃ 𝑧 ( 𝑡 = ⟨ ⟨ 𝑥 , 𝑦 ⟩ , 𝑧 ⟩ ∧ 𝜓 ) }
14		df-oprab	⊢ { ⟨ ⟨ 𝑥 , 𝑤 ⟩ , 𝑣 ⟩ ∣ 𝜒 } = { 𝑡 ∣ ∃ 𝑥 ∃ 𝑤 ∃ 𝑣 ( 𝑡 = ⟨ ⟨ 𝑥 , 𝑤 ⟩ , 𝑣 ⟩ ∧ 𝜒 ) }
15	12 13 14	3eqtr4g	⊢ ( 𝜑 → { ⟨ ⟨ 𝑥 , 𝑦 ⟩ , 𝑧 ⟩ ∣ 𝜓 } = { ⟨ ⟨ 𝑥 , 𝑤 ⟩ , 𝑣 ⟩ ∣ 𝜒 } )