| Step | Hyp | Ref
| Expression |
| 1 | | frsuc 8414 |
. . . 4
⊢ (𝐵 ∈ ω →
((rec((𝑥 ∈ V ↦
suc 𝑥), 𝐴) ↾ ω)‘suc 𝐵) = ((𝑥 ∈ V ↦ suc 𝑥)‘((rec((𝑥 ∈ V ↦ suc 𝑥), 𝐴) ↾ ω)‘𝐵))) |
| 2 | 1 | adantl 481 |
. . 3
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ ω) →
((rec((𝑥 ∈ V ↦
suc 𝑥), 𝐴) ↾ ω)‘suc 𝐵) = ((𝑥 ∈ V ↦ suc 𝑥)‘((rec((𝑥 ∈ V ↦ suc 𝑥), 𝐴) ↾ ω)‘𝐵))) |
| 3 | | peano2 7875 |
. . . . 5
⊢ (𝐵 ∈ ω → suc 𝐵 ∈
ω) |
| 4 | 3 | adantl 481 |
. . . 4
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ ω) → suc
𝐵 ∈
ω) |
| 5 | 4 | fvresd 6885 |
. . 3
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ ω) →
((rec((𝑥 ∈ V ↦
suc 𝑥), 𝐴) ↾ ω)‘suc 𝐵) = (rec((𝑥 ∈ V ↦ suc 𝑥), 𝐴)‘suc 𝐵)) |
| 6 | | fvres 6884 |
. . . . 5
⊢ (𝐵 ∈ ω →
((rec((𝑥 ∈ V ↦
suc 𝑥), 𝐴) ↾ ω)‘𝐵) = (rec((𝑥 ∈ V ↦ suc 𝑥), 𝐴)‘𝐵)) |
| 7 | 6 | adantl 481 |
. . . 4
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ ω) →
((rec((𝑥 ∈ V ↦
suc 𝑥), 𝐴) ↾ ω)‘𝐵) = (rec((𝑥 ∈ V ↦ suc 𝑥), 𝐴)‘𝐵)) |
| 8 | 7 | fveq2d 6869 |
. . 3
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ ω) → ((𝑥 ∈ V ↦ suc 𝑥)‘((rec((𝑥 ∈ V ↦ suc 𝑥), 𝐴) ↾ ω)‘𝐵)) = ((𝑥 ∈ V ↦ suc 𝑥)‘(rec((𝑥 ∈ V ↦ suc 𝑥), 𝐴)‘𝐵))) |
| 9 | 2, 5, 8 | 3eqtr3d 2773 |
. 2
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ ω) →
(rec((𝑥 ∈ V ↦
suc 𝑥), 𝐴)‘suc 𝐵) = ((𝑥 ∈ V ↦ suc 𝑥)‘(rec((𝑥 ∈ V ↦ suc 𝑥), 𝐴)‘𝐵))) |
| 10 | | nnon 7856 |
. . . 4
⊢ (𝐵 ∈ ω → 𝐵 ∈ On) |
| 11 | | onsuc 7794 |
. . . 4
⊢ (𝐵 ∈ On → suc 𝐵 ∈ On) |
| 12 | 10, 11 | syl 17 |
. . 3
⊢ (𝐵 ∈ ω → suc 𝐵 ∈ On) |
| 13 | | oav 8486 |
. . 3
⊢ ((𝐴 ∈ On ∧ suc 𝐵 ∈ On) → (𝐴 +o suc 𝐵) = (rec((𝑥 ∈ V ↦ suc 𝑥), 𝐴)‘suc 𝐵)) |
| 14 | 12, 13 | sylan2 593 |
. 2
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ ω) → (𝐴 +o suc 𝐵) = (rec((𝑥 ∈ V ↦ suc 𝑥), 𝐴)‘suc 𝐵)) |
| 15 | | ovex 7427 |
. . . 4
⊢ (𝐴 +o 𝐵) ∈ V |
| 16 | | suceq 6407 |
. . . . 5
⊢ (𝑥 = (𝐴 +o 𝐵) → suc 𝑥 = suc (𝐴 +o 𝐵)) |
| 17 | | eqid 2730 |
. . . . 5
⊢ (𝑥 ∈ V ↦ suc 𝑥) = (𝑥 ∈ V ↦ suc 𝑥) |
| 18 | 15 | sucex 7789 |
. . . . 5
⊢ suc
(𝐴 +o 𝐵) ∈ V |
| 19 | 16, 17, 18 | fvmpt 6975 |
. . . 4
⊢ ((𝐴 +o 𝐵) ∈ V → ((𝑥 ∈ V ↦ suc 𝑥)‘(𝐴 +o 𝐵)) = suc (𝐴 +o 𝐵)) |
| 20 | 15, 19 | ax-mp 5 |
. . 3
⊢ ((𝑥 ∈ V ↦ suc 𝑥)‘(𝐴 +o 𝐵)) = suc (𝐴 +o 𝐵) |
| 21 | | oav 8486 |
. . . . 5
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 +o 𝐵) = (rec((𝑥 ∈ V ↦ suc 𝑥), 𝐴)‘𝐵)) |
| 22 | 10, 21 | sylan2 593 |
. . . 4
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ ω) → (𝐴 +o 𝐵) = (rec((𝑥 ∈ V ↦ suc 𝑥), 𝐴)‘𝐵)) |
| 23 | 22 | fveq2d 6869 |
. . 3
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ ω) → ((𝑥 ∈ V ↦ suc 𝑥)‘(𝐴 +o 𝐵)) = ((𝑥 ∈ V ↦ suc 𝑥)‘(rec((𝑥 ∈ V ↦ suc 𝑥), 𝐴)‘𝐵))) |
| 24 | 20, 23 | eqtr3id 2779 |
. 2
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ ω) → suc
(𝐴 +o 𝐵) = ((𝑥 ∈ V ↦ suc 𝑥)‘(rec((𝑥 ∈ V ↦ suc 𝑥), 𝐴)‘𝐵))) |
| 25 | 9, 14, 24 | 3eqtr4d 2775 |
1
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ ω) → (𝐴 +o suc 𝐵) = suc (𝐴 +o 𝐵)) |