| Step | Hyp | Ref
| Expression |
| 1 | | onsuc 4537 |
. . . . . 6
⊢ (𝐵 ∈ On → suc 𝐵 ∈ On) |
| 2 | | oav2 6521 |
. . . . . 6
⊢ ((𝐴 ∈ On ∧ suc 𝐵 ∈ On) → (𝐴 +o suc 𝐵) = (𝐴 ∪ ∪
𝑥 ∈ suc 𝐵 suc (𝐴 +o 𝑥))) |
| 3 | 1, 2 | sylan2 286 |
. . . . 5
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 +o suc 𝐵) = (𝐴 ∪ ∪
𝑥 ∈ suc 𝐵 suc (𝐴 +o 𝑥))) |
| 4 | | df-suc 4406 |
. . . . . . . . . 10
⊢ suc 𝐵 = (𝐵 ∪ {𝐵}) |
| 5 | | iuneq1 3929 |
. . . . . . . . . 10
⊢ (suc
𝐵 = (𝐵 ∪ {𝐵}) → ∪ 𝑥 ∈ suc 𝐵 suc (𝐴 +o 𝑥) = ∪ 𝑥 ∈ (𝐵 ∪ {𝐵})suc (𝐴 +o 𝑥)) |
| 6 | 4, 5 | ax-mp 5 |
. . . . . . . . 9
⊢ ∪ 𝑥 ∈ suc 𝐵 suc (𝐴 +o 𝑥) = ∪ 𝑥 ∈ (𝐵 ∪ {𝐵})suc (𝐴 +o 𝑥) |
| 7 | | iunxun 3996 |
. . . . . . . . 9
⊢ ∪ 𝑥 ∈ (𝐵 ∪ {𝐵})suc (𝐴 +o 𝑥) = (∪
𝑥 ∈ 𝐵 suc (𝐴 +o 𝑥) ∪ ∪
𝑥 ∈ {𝐵}suc (𝐴 +o 𝑥)) |
| 8 | 6, 7 | eqtri 2217 |
. . . . . . . 8
⊢ ∪ 𝑥 ∈ suc 𝐵 suc (𝐴 +o 𝑥) = (∪
𝑥 ∈ 𝐵 suc (𝐴 +o 𝑥) ∪ ∪
𝑥 ∈ {𝐵}suc (𝐴 +o 𝑥)) |
| 9 | | oveq2 5930 |
. . . . . . . . . . 11
⊢ (𝑥 = 𝐵 → (𝐴 +o 𝑥) = (𝐴 +o 𝐵)) |
| 10 | | suceq 4437 |
. . . . . . . . . . 11
⊢ ((𝐴 +o 𝑥) = (𝐴 +o 𝐵) → suc (𝐴 +o 𝑥) = suc (𝐴 +o 𝐵)) |
| 11 | 9, 10 | syl 14 |
. . . . . . . . . 10
⊢ (𝑥 = 𝐵 → suc (𝐴 +o 𝑥) = suc (𝐴 +o 𝐵)) |
| 12 | 11 | iunxsng 3992 |
. . . . . . . . 9
⊢ (𝐵 ∈ On → ∪ 𝑥 ∈ {𝐵}suc (𝐴 +o 𝑥) = suc (𝐴 +o 𝐵)) |
| 13 | 12 | uneq2d 3317 |
. . . . . . . 8
⊢ (𝐵 ∈ On → (∪ 𝑥 ∈ 𝐵 suc (𝐴 +o 𝑥) ∪ ∪
𝑥 ∈ {𝐵}suc (𝐴 +o 𝑥)) = (∪
𝑥 ∈ 𝐵 suc (𝐴 +o 𝑥) ∪ suc (𝐴 +o 𝐵))) |
| 14 | 8, 13 | eqtrid 2241 |
. . . . . . 7
⊢ (𝐵 ∈ On → ∪ 𝑥 ∈ suc 𝐵 suc (𝐴 +o 𝑥) = (∪
𝑥 ∈ 𝐵 suc (𝐴 +o 𝑥) ∪ suc (𝐴 +o 𝐵))) |
| 15 | 14 | uneq2d 3317 |
. . . . . 6
⊢ (𝐵 ∈ On → (𝐴 ∪ ∪ 𝑥 ∈ suc 𝐵 suc (𝐴 +o 𝑥)) = (𝐴 ∪ (∪
𝑥 ∈ 𝐵 suc (𝐴 +o 𝑥) ∪ suc (𝐴 +o 𝐵)))) |
| 16 | 15 | adantl 277 |
. . . . 5
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 ∪ ∪ 𝑥 ∈ suc 𝐵 suc (𝐴 +o 𝑥)) = (𝐴 ∪ (∪
𝑥 ∈ 𝐵 suc (𝐴 +o 𝑥) ∪ suc (𝐴 +o 𝐵)))) |
| 17 | 3, 16 | eqtrd 2229 |
. . . 4
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 +o suc 𝐵) = (𝐴 ∪ (∪
𝑥 ∈ 𝐵 suc (𝐴 +o 𝑥) ∪ suc (𝐴 +o 𝐵)))) |
| 18 | | unass 3320 |
. . . 4
⊢ ((𝐴 ∪ ∪ 𝑥 ∈ 𝐵 suc (𝐴 +o 𝑥)) ∪ suc (𝐴 +o 𝐵)) = (𝐴 ∪ (∪
𝑥 ∈ 𝐵 suc (𝐴 +o 𝑥) ∪ suc (𝐴 +o 𝐵))) |
| 19 | 17, 18 | eqtr4di 2247 |
. . 3
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 +o suc 𝐵) = ((𝐴 ∪ ∪
𝑥 ∈ 𝐵 suc (𝐴 +o 𝑥)) ∪ suc (𝐴 +o 𝐵))) |
| 20 | | oav2 6521 |
. . . 4
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 +o 𝐵) = (𝐴 ∪ ∪
𝑥 ∈ 𝐵 suc (𝐴 +o 𝑥))) |
| 21 | 20 | uneq1d 3316 |
. . 3
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → ((𝐴 +o 𝐵) ∪ suc (𝐴 +o 𝐵)) = ((𝐴 ∪ ∪
𝑥 ∈ 𝐵 suc (𝐴 +o 𝑥)) ∪ suc (𝐴 +o 𝐵))) |
| 22 | 19, 21 | eqtr4d 2232 |
. 2
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 +o suc 𝐵) = ((𝐴 +o 𝐵) ∪ suc (𝐴 +o 𝐵))) |
| 23 | | sssucid 4450 |
. . 3
⊢ (𝐴 +o 𝐵) ⊆ suc (𝐴 +o 𝐵) |
| 24 | | ssequn1 3333 |
. . 3
⊢ ((𝐴 +o 𝐵) ⊆ suc (𝐴 +o 𝐵) ↔ ((𝐴 +o 𝐵) ∪ suc (𝐴 +o 𝐵)) = suc (𝐴 +o 𝐵)) |
| 25 | 23, 24 | mpbi 145 |
. 2
⊢ ((𝐴 +o 𝐵) ∪ suc (𝐴 +o 𝐵)) = suc (𝐴 +o 𝐵) |
| 26 | 22, 25 | eqtrdi 2245 |
1
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 +o suc 𝐵) = suc (𝐴 +o 𝐵)) |