| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | nfv 1914 | . . . . 5
⊢
Ⅎ𝑧 𝑥 ∈ 𝐴 | 
| 2 |  | cbvmpox.1 | . . . . . 6
⊢
Ⅎ𝑧𝐵 | 
| 3 | 2 | nfcri 2897 | . . . . 5
⊢
Ⅎ𝑧 𝑦 ∈ 𝐵 | 
| 4 | 1, 3 | nfan 1899 | . . . 4
⊢
Ⅎ𝑧(𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) | 
| 5 |  | cbvmpox.3 | . . . . 5
⊢
Ⅎ𝑧𝐶 | 
| 6 | 5 | nfeq2 2923 | . . . 4
⊢
Ⅎ𝑧 𝑢 = 𝐶 | 
| 7 | 4, 6 | nfan 1899 | . . 3
⊢
Ⅎ𝑧((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) ∧ 𝑢 = 𝐶) | 
| 8 |  | nfv 1914 | . . . . 5
⊢
Ⅎ𝑤 𝑥 ∈ 𝐴 | 
| 9 |  | nfcv 2905 | . . . . . 6
⊢
Ⅎ𝑤𝐵 | 
| 10 | 9 | nfcri 2897 | . . . . 5
⊢
Ⅎ𝑤 𝑦 ∈ 𝐵 | 
| 11 | 8, 10 | nfan 1899 | . . . 4
⊢
Ⅎ𝑤(𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) | 
| 12 |  | cbvmpox.4 | . . . . 5
⊢
Ⅎ𝑤𝐶 | 
| 13 | 12 | nfeq2 2923 | . . . 4
⊢
Ⅎ𝑤 𝑢 = 𝐶 | 
| 14 | 11, 13 | nfan 1899 | . . 3
⊢
Ⅎ𝑤((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) ∧ 𝑢 = 𝐶) | 
| 15 |  | nfv 1914 | . . . . 5
⊢
Ⅎ𝑥 𝑧 ∈ 𝐴 | 
| 16 |  | cbvmpox.2 | . . . . . 6
⊢
Ⅎ𝑥𝐷 | 
| 17 | 16 | nfcri 2897 | . . . . 5
⊢
Ⅎ𝑥 𝑤 ∈ 𝐷 | 
| 18 | 15, 17 | nfan 1899 | . . . 4
⊢
Ⅎ𝑥(𝑧 ∈ 𝐴 ∧ 𝑤 ∈ 𝐷) | 
| 19 |  | cbvmpox.5 | . . . . 5
⊢
Ⅎ𝑥𝐸 | 
| 20 | 19 | nfeq2 2923 | . . . 4
⊢
Ⅎ𝑥 𝑢 = 𝐸 | 
| 21 | 18, 20 | nfan 1899 | . . 3
⊢
Ⅎ𝑥((𝑧 ∈ 𝐴 ∧ 𝑤 ∈ 𝐷) ∧ 𝑢 = 𝐸) | 
| 22 |  | nfv 1914 | . . . 4
⊢
Ⅎ𝑦(𝑧 ∈ 𝐴 ∧ 𝑤 ∈ 𝐷) | 
| 23 |  | cbvmpox.6 | . . . . 5
⊢
Ⅎ𝑦𝐸 | 
| 24 | 23 | nfeq2 2923 | . . . 4
⊢
Ⅎ𝑦 𝑢 = 𝐸 | 
| 25 | 22, 24 | nfan 1899 | . . 3
⊢
Ⅎ𝑦((𝑧 ∈ 𝐴 ∧ 𝑤 ∈ 𝐷) ∧ 𝑢 = 𝐸) | 
| 26 |  | eleq1w 2824 | . . . . . 6
⊢ (𝑥 = 𝑧 → (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴)) | 
| 27 | 26 | adantr 480 | . . . . 5
⊢ ((𝑥 = 𝑧 ∧ 𝑦 = 𝑤) → (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴)) | 
| 28 |  | cbvmpox.7 | . . . . . . 7
⊢ (𝑥 = 𝑧 → 𝐵 = 𝐷) | 
| 29 | 28 | eleq2d 2827 | . . . . . 6
⊢ (𝑥 = 𝑧 → (𝑦 ∈ 𝐵 ↔ 𝑦 ∈ 𝐷)) | 
| 30 |  | eleq1w 2824 | . . . . . 6
⊢ (𝑦 = 𝑤 → (𝑦 ∈ 𝐷 ↔ 𝑤 ∈ 𝐷)) | 
| 31 | 29, 30 | sylan9bb 509 | . . . . 5
⊢ ((𝑥 = 𝑧 ∧ 𝑦 = 𝑤) → (𝑦 ∈ 𝐵 ↔ 𝑤 ∈ 𝐷)) | 
| 32 | 27, 31 | anbi12d 632 | . . . 4
⊢ ((𝑥 = 𝑧 ∧ 𝑦 = 𝑤) → ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) ↔ (𝑧 ∈ 𝐴 ∧ 𝑤 ∈ 𝐷))) | 
| 33 |  | cbvmpox.8 | . . . . 5
⊢ ((𝑥 = 𝑧 ∧ 𝑦 = 𝑤) → 𝐶 = 𝐸) | 
| 34 | 33 | eqeq2d 2748 | . . . 4
⊢ ((𝑥 = 𝑧 ∧ 𝑦 = 𝑤) → (𝑢 = 𝐶 ↔ 𝑢 = 𝐸)) | 
| 35 | 32, 34 | anbi12d 632 | . . 3
⊢ ((𝑥 = 𝑧 ∧ 𝑦 = 𝑤) → (((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) ∧ 𝑢 = 𝐶) ↔ ((𝑧 ∈ 𝐴 ∧ 𝑤 ∈ 𝐷) ∧ 𝑢 = 𝐸))) | 
| 36 | 7, 14, 21, 25, 35 | cbvoprab12 7522 | . 2
⊢
{〈〈𝑥,
𝑦〉, 𝑢〉 ∣ ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) ∧ 𝑢 = 𝐶)} = {〈〈𝑧, 𝑤〉, 𝑢〉 ∣ ((𝑧 ∈ 𝐴 ∧ 𝑤 ∈ 𝐷) ∧ 𝑢 = 𝐸)} | 
| 37 |  | df-mpo 7436 | . 2
⊢ (𝑥 ∈ 𝐴, 𝑦 ∈ 𝐵 ↦ 𝐶) = {〈〈𝑥, 𝑦〉, 𝑢〉 ∣ ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) ∧ 𝑢 = 𝐶)} | 
| 38 |  | df-mpo 7436 | . 2
⊢ (𝑧 ∈ 𝐴, 𝑤 ∈ 𝐷 ↦ 𝐸) = {〈〈𝑧, 𝑤〉, 𝑢〉 ∣ ((𝑧 ∈ 𝐴 ∧ 𝑤 ∈ 𝐷) ∧ 𝑢 = 𝐸)} | 
| 39 | 36, 37, 38 | 3eqtr4i 2775 | 1
⊢ (𝑥 ∈ 𝐴, 𝑦 ∈ 𝐵 ↦ 𝐶) = (𝑧 ∈ 𝐴, 𝑤 ∈ 𝐷 ↦ 𝐸) |