Proof of Theorem iseqvalcbv
| Step | Hyp | Ref
 | Expression | 
| 1 |   | oveq1 5929 | 
. . . . . . . . . 10
⊢ (𝑐 = 𝑧 → (𝑐 + 1) = (𝑧 + 1)) | 
| 2 | 1 | fveq2d 5562 | 
. . . . . . . . 9
⊢ (𝑐 = 𝑧 → (𝐹‘(𝑐 + 1)) = (𝐹‘(𝑧 + 1))) | 
| 3 | 2 | oveq2d 5938 | 
. . . . . . . 8
⊢ (𝑐 = 𝑧 → (𝑑 + (𝐹‘(𝑐 + 1))) = (𝑑 + (𝐹‘(𝑧 + 1)))) | 
| 4 |   | oveq1 5929 | 
. . . . . . . 8
⊢ (𝑑 = 𝑤 → (𝑑 + (𝐹‘(𝑧 + 1))) = (𝑤 + (𝐹‘(𝑧 + 1)))) | 
| 5 | 3, 4 | cbvmpov 6002 | 
. . . . . . 7
⊢ (𝑐 ∈
(ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1)))) = (𝑧 ∈ (ℤ≥‘𝑀), 𝑤 ∈ 𝑆 ↦ (𝑤 + (𝐹‘(𝑧 + 1)))) | 
| 6 | 5 | oveqi 5935 | 
. . . . . 6
⊢ (𝑥(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑦) = (𝑥(𝑧 ∈ (ℤ≥‘𝑀), 𝑤 ∈ 𝑆 ↦ (𝑤 + (𝐹‘(𝑧 + 1))))𝑦) | 
| 7 | 6 | opeq2i 3812 | 
. . . . 5
⊢
〈(𝑥 + 1),
(𝑥(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑦)〉 = 〈(𝑥 + 1), (𝑥(𝑧 ∈ (ℤ≥‘𝑀), 𝑤 ∈ 𝑆 ↦ (𝑤 + (𝐹‘(𝑧 + 1))))𝑦)〉 | 
| 8 | 7 | a1i 9 | 
. . . 4
⊢ ((𝑥 ∈
(ℤ≥‘𝑀) ∧ 𝑦 ∈ 𝑇) → 〈(𝑥 + 1), (𝑥(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑦)〉 = 〈(𝑥 + 1), (𝑥(𝑧 ∈ (ℤ≥‘𝑀), 𝑤 ∈ 𝑆 ↦ (𝑤 + (𝐹‘(𝑧 + 1))))𝑦)〉) | 
| 9 | 8 | mpoeq3ia 5987 | 
. . 3
⊢ (𝑥 ∈
(ℤ≥‘𝑀), 𝑦 ∈ 𝑇 ↦ 〈(𝑥 + 1), (𝑥(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑦)〉) = (𝑥 ∈ (ℤ≥‘𝑀), 𝑦 ∈ 𝑇 ↦ 〈(𝑥 + 1), (𝑥(𝑧 ∈ (ℤ≥‘𝑀), 𝑤 ∈ 𝑆 ↦ (𝑤 + (𝐹‘(𝑧 + 1))))𝑦)〉) | 
| 10 |   | oveq1 5929 | 
. . . . 5
⊢ (𝑥 = 𝑎 → (𝑥 + 1) = (𝑎 + 1)) | 
| 11 |   | oveq1 5929 | 
. . . . 5
⊢ (𝑥 = 𝑎 → (𝑥(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑦) = (𝑎(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑦)) | 
| 12 | 10, 11 | opeq12d 3816 | 
. . . 4
⊢ (𝑥 = 𝑎 → 〈(𝑥 + 1), (𝑥(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑦)〉 = 〈(𝑎 + 1), (𝑎(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑦)〉) | 
| 13 |   | oveq2 5930 | 
. . . . 5
⊢ (𝑦 = 𝑏 → (𝑎(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑦) = (𝑎(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑏)) | 
| 14 | 13 | opeq2d 3815 | 
. . . 4
⊢ (𝑦 = 𝑏 → 〈(𝑎 + 1), (𝑎(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑦)〉 = 〈(𝑎 + 1), (𝑎(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑏)〉) | 
| 15 | 12, 14 | cbvmpov 6002 | 
. . 3
⊢ (𝑥 ∈
(ℤ≥‘𝑀), 𝑦 ∈ 𝑇 ↦ 〈(𝑥 + 1), (𝑥(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑦)〉) = (𝑎 ∈ (ℤ≥‘𝑀), 𝑏 ∈ 𝑇 ↦ 〈(𝑎 + 1), (𝑎(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑏)〉) | 
| 16 | 9, 15 | eqtr3i 2219 | 
. 2
⊢ (𝑥 ∈
(ℤ≥‘𝑀), 𝑦 ∈ 𝑇 ↦ 〈(𝑥 + 1), (𝑥(𝑧 ∈ (ℤ≥‘𝑀), 𝑤 ∈ 𝑆 ↦ (𝑤 + (𝐹‘(𝑧 + 1))))𝑦)〉) = (𝑎 ∈ (ℤ≥‘𝑀), 𝑏 ∈ 𝑇 ↦ 〈(𝑎 + 1), (𝑎(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑏)〉) | 
| 17 |   | freceq1 6450 | 
. 2
⊢ ((𝑥 ∈
(ℤ≥‘𝑀), 𝑦 ∈ 𝑇 ↦ 〈(𝑥 + 1), (𝑥(𝑧 ∈ (ℤ≥‘𝑀), 𝑤 ∈ 𝑆 ↦ (𝑤 + (𝐹‘(𝑧 + 1))))𝑦)〉) = (𝑎 ∈ (ℤ≥‘𝑀), 𝑏 ∈ 𝑇 ↦ 〈(𝑎 + 1), (𝑎(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑏)〉) → frec((𝑥 ∈ (ℤ≥‘𝑀), 𝑦 ∈ 𝑇 ↦ 〈(𝑥 + 1), (𝑥(𝑧 ∈ (ℤ≥‘𝑀), 𝑤 ∈ 𝑆 ↦ (𝑤 + (𝐹‘(𝑧 + 1))))𝑦)〉), 〈𝑀, (𝐹‘𝑀)〉) = frec((𝑎 ∈ (ℤ≥‘𝑀), 𝑏 ∈ 𝑇 ↦ 〈(𝑎 + 1), (𝑎(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑏)〉), 〈𝑀, (𝐹‘𝑀)〉)) | 
| 18 | 16, 17 | ax-mp 5 | 
1
⊢
frec((𝑥 ∈
(ℤ≥‘𝑀), 𝑦 ∈ 𝑇 ↦ 〈(𝑥 + 1), (𝑥(𝑧 ∈ (ℤ≥‘𝑀), 𝑤 ∈ 𝑆 ↦ (𝑤 + (𝐹‘(𝑧 + 1))))𝑦)〉), 〈𝑀, (𝐹‘𝑀)〉) = frec((𝑎 ∈ (ℤ≥‘𝑀), 𝑏 ∈ 𝑇 ↦ 〈(𝑎 + 1), (𝑎(𝑐 ∈ (ℤ≥‘𝑀), 𝑑 ∈ 𝑆 ↦ (𝑑 + (𝐹‘(𝑐 + 1))))𝑏)〉), 〈𝑀, (𝐹‘𝑀)〉) |