Theorem cbvmpo2vw2 36813

Description: Change domains and the second bound variable in a maps-to function, using implicit substitution. (Contributed by GG, 14-Aug-2025.)

Hypotheses

Ref	Expression
cbvmpo2vw2.1	⊢ (𝑦 = 𝑧 → 𝐸 = 𝐹)
cbvmpo2vw2.2	⊢ (𝑦 = 𝑧 → 𝐶 = 𝐷)
cbvmpo2vw2.3	⊢ (𝑦 = 𝑧 → 𝐴 = 𝐵)

Assertion

Ref	Expression
cbvmpo2vw2	⊢ (𝑥 ∈ 𝐴, 𝑦 ∈ 𝐶 ↦ 𝐸) = (𝑥 ∈ 𝐵, 𝑧 ∈ 𝐷 ↦ 𝐹)

Distinct variable groups:   𝑥,𝑦,𝑧   𝑧,𝐴   𝑦,𝐵   𝑧,𝐶   𝑦,𝐷   𝑧,𝐸   𝑦,𝐹

Allowed substitution hints:   𝐴(𝑥, 𝑦)   𝐵(𝑥, 𝑧)   𝐶(𝑥, 𝑦)   𝐷(𝑥, 𝑧)   𝐸(𝑥, 𝑦)   𝐹(𝑥, 𝑧)

Proof of Theorem cbvmpo2vw2

Dummy variable 𝑡 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		cbvmpo2vw2.3	. . . . . 6 ⊢ (𝑦 = 𝑧 → 𝐴 = 𝐵)
2	1	eleq2d 2851	. . . . 5 ⊢ (𝑦 = 𝑧 → (𝑥 ∈ 𝐴 ↔ 𝑥 ∈ 𝐵))
3		id 23	. . . . . 6 ⊢ (𝑦 = 𝑧 → 𝑦 = 𝑧)
4		cbvmpo2vw2.2	. . . . . 6 ⊢ (𝑦 = 𝑧 → 𝐶 = 𝐷)
5	3, 4	eleq12d 2859	. . . . 5 ⊢ (𝑦 = 𝑧 → (𝑦 ∈ 𝐶 ↔ 𝑧 ∈ 𝐷))
6	2, 5	anbi12d 644	. . . 4 ⊢ (𝑦 = 𝑧 → ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐶) ↔ (𝑥 ∈ 𝐵 ∧ 𝑧 ∈ 𝐷)))
7		cbvmpo2vw2.1	. . . . 5 ⊢ (𝑦 = 𝑧 → 𝐸 = 𝐹)
8	7	eqeq2d 2776	. . . 4 ⊢ (𝑦 = 𝑧 → (𝑡 = 𝐸 ↔ 𝑡 = 𝐹))
9	6, 8	anbi12d 644	. . 3 ⊢ (𝑦 = 𝑧 → (((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐶) ∧ 𝑡 = 𝐸) ↔ ((𝑥 ∈ 𝐵 ∧ 𝑧 ∈ 𝐷) ∧ 𝑡 = 𝐹)))
10	9	cbvoprab2vw 36807	. 2 ⊢ {⟨⟨𝑥, 𝑦⟩, 𝑡⟩ ∣ ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐶) ∧ 𝑡 = 𝐸)} = {⟨⟨𝑥, 𝑧⟩, 𝑡⟩ ∣ ((𝑥 ∈ 𝐵 ∧ 𝑧 ∈ 𝐷) ∧ 𝑡 = 𝐹)}
11		df-mpo 7424	. 2 ⊢ (𝑥 ∈ 𝐴, 𝑦 ∈ 𝐶 ↦ 𝐸) = {⟨⟨𝑥, 𝑦⟩, 𝑡⟩ ∣ ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐶) ∧ 𝑡 = 𝐸)}
12		df-mpo 7424	. 2 ⊢ (𝑥 ∈ 𝐵, 𝑧 ∈ 𝐷 ↦ 𝐹) = {⟨⟨𝑥, 𝑧⟩, 𝑡⟩ ∣ ((𝑥 ∈ 𝐵 ∧ 𝑧 ∈ 𝐷) ∧ 𝑡 = 𝐹)}
13	10, 11, 12	3eqtr4i 2798	1 ⊢ (𝑥 ∈ 𝐴, 𝑦 ∈ 𝐶 ↦ 𝐸) = (𝑥 ∈ 𝐵, 𝑧 ∈ 𝐷 ↦ 𝐹)

This proof depends on syntax axioms:   → wi 4   ∧ wa 401   = wceq 1570   ∈ wcel 2146  {coprab 7420   ∈ cmpo 7421

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-8 2148  ax-9 2156  ax-ext 2737

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1813  df-sb 2100  df-clab 2744  df-cleq 2757  df-clel 2840  df-rab 3419  df-v 3459  df-dif 3909  df-un 3911  df-ss 3923  df-nul 4287  df-if 4490  df-sn 4592  df-pr 4594  df-op 4598  df-oprab 7423  df-mpo 7424

This theorem is used by: (None)