Proof of Theorem onntri45
| Step | Hyp | Ref
| Expression |
| 1 | | pw1on 7309 |
. . . . 5
⊢ 𝒫
1o ∈ On |
| 2 | 1 | onsuci 4553 |
. . . 4
⊢ suc
𝒫 1o ∈ On |
| 3 | | 3on 6494 |
. . . 4
⊢
3o ∈ On |
| 4 | | sseq1 3207 |
. . . . . . . 8
⊢ (𝑥 = suc 𝒫 1o
→ (𝑥 ⊆ 𝑦 ↔ suc 𝒫
1o ⊆ 𝑦)) |
| 5 | | sseq2 3208 |
. . . . . . . 8
⊢ (𝑥 = suc 𝒫 1o
→ (𝑦 ⊆ 𝑥 ↔ 𝑦 ⊆ suc 𝒫
1o)) |
| 6 | 4, 5 | orbi12d 794 |
. . . . . . 7
⊢ (𝑥 = suc 𝒫 1o
→ ((𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥) ↔ (suc 𝒫 1o ⊆
𝑦 ∨ 𝑦 ⊆ suc 𝒫
1o))) |
| 7 | 6 | notbid 668 |
. . . . . 6
⊢ (𝑥 = suc 𝒫 1o
→ (¬ (𝑥 ⊆
𝑦 ∨ 𝑦 ⊆ 𝑥) ↔ ¬ (suc 𝒫 1o
⊆ 𝑦 ∨ 𝑦 ⊆ suc 𝒫
1o))) |
| 8 | 7 | notbid 668 |
. . . . 5
⊢ (𝑥 = suc 𝒫 1o
→ (¬ ¬ (𝑥
⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥) ↔ ¬ ¬ (suc 𝒫
1o ⊆ 𝑦
∨ 𝑦 ⊆ suc
𝒫 1o))) |
| 9 | | sseq2 3208 |
. . . . . . . 8
⊢ (𝑦 = 3o → (suc
𝒫 1o ⊆ 𝑦 ↔ suc 𝒫 1o ⊆
3o)) |
| 10 | | sseq1 3207 |
. . . . . . . 8
⊢ (𝑦 = 3o → (𝑦 ⊆ suc 𝒫
1o ↔ 3o ⊆ suc 𝒫
1o)) |
| 11 | 9, 10 | orbi12d 794 |
. . . . . . 7
⊢ (𝑦 = 3o → ((suc
𝒫 1o ⊆ 𝑦 ∨ 𝑦 ⊆ suc 𝒫 1o) ↔
(suc 𝒫 1o ⊆ 3o ∨ 3o ⊆
suc 𝒫 1o))) |
| 12 | 11 | notbid 668 |
. . . . . 6
⊢ (𝑦 = 3o → (¬
(suc 𝒫 1o ⊆ 𝑦 ∨ 𝑦 ⊆ suc 𝒫 1o) ↔
¬ (suc 𝒫 1o ⊆ 3o ∨ 3o
⊆ suc 𝒫 1o))) |
| 13 | 12 | notbid 668 |
. . . . 5
⊢ (𝑦 = 3o → (¬
¬ (suc 𝒫 1o ⊆ 𝑦 ∨ 𝑦 ⊆ suc 𝒫 1o) ↔
¬ ¬ (suc 𝒫 1o ⊆ 3o ∨
3o ⊆ suc 𝒫 1o))) |
| 14 | 8, 13 | rspc2v 2881 |
. . . 4
⊢ ((suc
𝒫 1o ∈ On ∧ 3o ∈ On) →
(∀𝑥 ∈ On
∀𝑦 ∈ On ¬
¬ (𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥) → ¬ ¬ (suc 𝒫
1o ⊆ 3o ∨ 3o ⊆ suc 𝒫
1o))) |
| 15 | 2, 3, 14 | mp2an 426 |
. . 3
⊢
(∀𝑥 ∈ On
∀𝑦 ∈ On ¬
¬ (𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥) → ¬ ¬ (suc 𝒫
1o ⊆ 3o ∨ 3o ⊆ suc 𝒫
1o)) |
| 16 | | ioran 753 |
. . 3
⊢ (¬
(suc 𝒫 1o ⊆ 3o ∨ 3o ⊆
suc 𝒫 1o) ↔ (¬ suc 𝒫 1o ⊆
3o ∧ ¬ 3o ⊆ suc 𝒫
1o)) |
| 17 | 15, 16 | sylnib 677 |
. 2
⊢
(∀𝑥 ∈ On
∀𝑦 ∈ On ¬
¬ (𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥) → ¬ (¬ suc 𝒫
1o ⊆ 3o ∧ ¬ 3o ⊆ suc
𝒫 1o)) |
| 18 | | sucpw1nss3 7318 |
. . 3
⊢ (¬
EXMID → ¬ suc 𝒫 1o ⊆
3o) |
| 19 | | 3nsssucpw1 7319 |
. . 3
⊢ (¬
EXMID → ¬ 3o ⊆ suc 𝒫
1o) |
| 20 | 18, 19 | jca 306 |
. 2
⊢ (¬
EXMID → (¬ suc 𝒫 1o ⊆
3o ∧ ¬ 3o ⊆ suc 𝒫
1o)) |
| 21 | 17, 20 | nsyl 629 |
1
⊢
(∀𝑥 ∈ On
∀𝑦 ∈ On ¬
¬ (𝑥 ⊆ 𝑦 ∨ 𝑦 ⊆ 𝑥) → ¬ ¬
EXMID) |