| Step | Hyp | Ref
| Expression |
| 1 | | sssucid 6464 |
. . . . . . 7
⊢ 𝐴 ⊆ suc 𝐴 |
| 2 | | id 22 |
. . . . . . . 8
⊢ (Tr 𝐴 → Tr 𝐴) |
| 3 | | id 22 |
. . . . . . . . 9
⊢ ((𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴) → (𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴)) |
| 4 | 3 | simpld 494 |
. . . . . . . 8
⊢ ((𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴) → 𝑧 ∈ 𝑦) |
| 5 | | id 22 |
. . . . . . . 8
⊢ (𝑦 ∈ 𝐴 → 𝑦 ∈ 𝐴) |
| 6 | | trel 5268 |
. . . . . . . . . 10
⊢ (Tr 𝐴 → ((𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐴) → 𝑧 ∈ 𝐴)) |
| 7 | 6 | 3impib 1117 |
. . . . . . . . 9
⊢ ((Tr
𝐴 ∧ 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐴) → 𝑧 ∈ 𝐴) |
| 8 | 7 | idiALT 44498 |
. . . . . . . 8
⊢ ((Tr
𝐴 ∧ 𝑧 ∈ 𝑦 ∧ 𝑦 ∈ 𝐴) → 𝑧 ∈ 𝐴) |
| 9 | 2, 4, 5, 8 | syl3an 1161 |
. . . . . . 7
⊢ ((Tr
𝐴 ∧ (𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴) ∧ 𝑦 ∈ 𝐴) → 𝑧 ∈ 𝐴) |
| 10 | 1, 9 | sselid 3981 |
. . . . . 6
⊢ ((Tr
𝐴 ∧ (𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴) ∧ 𝑦 ∈ 𝐴) → 𝑧 ∈ suc 𝐴) |
| 11 | 10 | 3expia 1122 |
. . . . 5
⊢ ((Tr
𝐴 ∧ (𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴)) → (𝑦 ∈ 𝐴 → 𝑧 ∈ suc 𝐴)) |
| 12 | 4 | adantr 480 |
. . . . . . . . 9
⊢ (((𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴) ∧ 𝑦 = 𝐴) → 𝑧 ∈ 𝑦) |
| 13 | | id 22 |
. . . . . . . . . 10
⊢ (𝑦 = 𝐴 → 𝑦 = 𝐴) |
| 14 | 13 | adantl 481 |
. . . . . . . . 9
⊢ (((𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴) ∧ 𝑦 = 𝐴) → 𝑦 = 𝐴) |
| 15 | 12, 14 | eleqtrd 2843 |
. . . . . . . 8
⊢ (((𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴) ∧ 𝑦 = 𝐴) → 𝑧 ∈ 𝐴) |
| 16 | 1, 15 | sselid 3981 |
. . . . . . 7
⊢ (((𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴) ∧ 𝑦 = 𝐴) → 𝑧 ∈ suc 𝐴) |
| 17 | 16 | ex 412 |
. . . . . 6
⊢ ((𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴) → (𝑦 = 𝐴 → 𝑧 ∈ suc 𝐴)) |
| 18 | 17 | adantl 481 |
. . . . 5
⊢ ((Tr
𝐴 ∧ (𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴)) → (𝑦 = 𝐴 → 𝑧 ∈ suc 𝐴)) |
| 19 | 3 | simprd 495 |
. . . . . . 7
⊢ ((𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴) → 𝑦 ∈ suc 𝐴) |
| 20 | | elsuci 6451 |
. . . . . . 7
⊢ (𝑦 ∈ suc 𝐴 → (𝑦 ∈ 𝐴 ∨ 𝑦 = 𝐴)) |
| 21 | 19, 20 | syl 17 |
. . . . . 6
⊢ ((𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴) → (𝑦 ∈ 𝐴 ∨ 𝑦 = 𝐴)) |
| 22 | 21 | adantl 481 |
. . . . 5
⊢ ((Tr
𝐴 ∧ (𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴)) → (𝑦 ∈ 𝐴 ∨ 𝑦 = 𝐴)) |
| 23 | 11, 18, 22 | mpjaod 861 |
. . . 4
⊢ ((Tr
𝐴 ∧ (𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴)) → 𝑧 ∈ suc 𝐴) |
| 24 | 23 | ex 412 |
. . 3
⊢ (Tr 𝐴 → ((𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴) → 𝑧 ∈ suc 𝐴)) |
| 25 | 24 | alrimivv 1928 |
. 2
⊢ (Tr 𝐴 → ∀𝑧∀𝑦((𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴) → 𝑧 ∈ suc 𝐴)) |
| 26 | | dftr2 5261 |
. . 3
⊢ (Tr suc
𝐴 ↔ ∀𝑧∀𝑦((𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴) → 𝑧 ∈ suc 𝐴)) |
| 27 | 26 | biimpri 228 |
. 2
⊢
(∀𝑧∀𝑦((𝑧 ∈ 𝑦 ∧ 𝑦 ∈ suc 𝐴) → 𝑧 ∈ suc 𝐴) → Tr suc 𝐴) |
| 28 | 25, 27 | syl 17 |
1
⊢ (Tr 𝐴 → Tr suc 𝐴) |