Proof of Theorem rankel
| Step | Hyp | Ref
| Expression |
| 1 | | eqid 1522 |
. . . . 5
⊢ (rank ‘A) = (rank ‘A) |
| 2 | | rankr1g 4737 |
. . . . 5
⊢ (A ∈ B → ((rank ‘A) = (rank ‘A) ↔ (¬ A ∈
(R1 ‘(rank ‘A)) ⋀ A ∈
(R1 ‘suc (rank ‘A))))) |
| 3 | 1, 2 | mpbii 200 |
. . . 4
⊢ (A ∈ B → (¬ A ∈
(R1 ‘(rank ‘A)) ⋀ A ∈
(R1 ‘suc (rank ‘A)))) |
| 4 | 3 | pm3.26d 328 |
. . 3
⊢ (A ∈ B → ¬ A
∈ (R1 ‘(rank
‘A))) |
| 5 | | rankon 4733 |
. . . . . . . 8
⊢ (rank ‘A) ∈ On |
| 6 | | r1suc 4714 |
. . . . . . . 8
⊢ ((rank ‘A) ∈ On →
(R1 ‘suc (rank ‘A)) = ℘(R1 ‘(rank
‘A))) |
| 7 | 5, 6 | ax-mp 7 |
. . . . . . 7
⊢ (R1
‘suc (rank ‘A)) = ℘(R1 ‘(rank
‘A)) |
| 8 | 7 | eleq2i 1585 |
. . . . . 6
⊢ (B ∈
(R1 ‘suc (rank ‘A)) ↔ B
∈ ℘(R1 ‘(rank
‘A))) |
| 9 | | rankel.1 |
. . . . . . 7
⊢ B ∈
V |
| 10 | 9 | elpw 2456 |
. . . . . 6
⊢ (B ∈ ℘(R1 ‘(rank
‘A)) ↔ B ⊆
(R1 ‘(rank ‘A))) |
| 11 | 8, 10 | bitri 180 |
. . . . 5
⊢ (B ∈
(R1 ‘suc (rank ‘A)) ↔ B
⊆ (R1 ‘(rank
‘A))) |
| 12 | | ssel 2114 |
. . . . 5
⊢ (B ⊆
(R1 ‘(rank ‘A)) → (A
∈ B
→ A ∈ (R1 ‘(rank
‘A)))) |
| 13 | 11, 12 | sylbi 206 |
. . . 4
⊢ (B ∈
(R1 ‘suc (rank ‘A)) → (A
∈ B
→ A ∈ (R1 ‘(rank
‘A)))) |
| 14 | 13 | com12 11 |
. . 3
⊢ (A ∈ B → (B
∈ (R1 ‘suc (rank
‘A)) → A ∈
(R1 ‘(rank ‘A)))) |
| 15 | 4, 14 | mtod 114 |
. 2
⊢ (A ∈ B → ¬ B
∈ (R1 ‘suc (rank
‘A))) |
| 16 | | rankon 4733 |
. . . 4
⊢ (rank ‘B) ∈ On |
| 17 | | ontri1 3038 |
. . . 4
⊢ (((rank ‘B) ∈ On ⋀ (rank ‘A) ∈ On) →
((rank ‘B) ⊆ (rank ‘A) ↔ ¬ (rank ‘A) ∈ (rank
‘B))) |
| 18 | 16, 5, 17 | mp2an 709 |
. . 3
⊢ ((rank ‘B) ⊆ (rank
‘A) ↔ ¬ (rank
‘A) ∈ (rank ‘B)) |
| 19 | 16 | onordi 3152 |
. . . . 5
⊢ Ord (rank ‘B) |
| 20 | 5 | onordi 3152 |
. . . . 5
⊢ Ord (rank ‘A) |
| 21 | | ordsucsssuc 3131 |
. . . . 5
⊢ ((Ord (rank
‘B) ⋀ Ord (rank ‘A)) → ((rank ‘B) ⊆ (rank
‘A) ↔ suc (rank ‘B) ⊆ suc (rank
‘A))) |
| 22 | 19, 20, 21 | mp2an 709 |
. . . 4
⊢ ((rank ‘B) ⊆ (rank
‘A) ↔ suc (rank ‘B) ⊆ suc (rank
‘A)) |
| 23 | 9 | rankid 4734 |
. . . . 5
⊢ B ∈
(R1 ‘suc (rank ‘B)) |
| 24 | 16 | onsuci 3162 |
. . . . . . 7
⊢ suc (rank ‘B) ∈ On |
| 25 | 5 | onsuci 3162 |
. . . . . . 7
⊢ suc (rank ‘A) ∈ On |
| 26 | | r1ord3 4719 |
. . . . . . 7
⊢ ((suc (rank
‘B) ∈ On ⋀ suc (rank
‘A) ∈ On) → (suc (rank ‘B) ⊆ suc (rank
‘A) → (R1
‘suc (rank ‘B)) ⊆ (R1 ‘suc (rank
‘A)))) |
| 27 | 24, 25, 26 | mp2an 709 |
. . . . . 6
⊢ (suc (rank ‘B) ⊆ suc (rank
‘A) → (R1
‘suc (rank ‘B)) ⊆ (R1 ‘suc (rank
‘A))) |
| 28 | 27 | sseld 2118 |
. . . . 5
⊢ (suc (rank ‘B) ⊆ suc (rank
‘A) → (B ∈
(R1 ‘suc (rank ‘B)) → B
∈ (R1 ‘suc (rank
‘A)))) |
| 29 | 23, 28 | mpi 44 |
. . . 4
⊢ (suc (rank ‘B) ⊆ suc (rank
‘A) → B ∈
(R1 ‘suc (rank ‘A))) |
| 30 | 22, 29 | sylbi 206 |
. . 3
⊢ ((rank ‘B) ⊆ (rank
‘A) → B ∈
(R1 ‘suc (rank ‘A))) |
| 31 | 18, 30 | sylbir 208 |
. 2
⊢ (¬ (rank
‘A) ∈ (rank ‘B) → B
∈ (R1 ‘suc (rank
‘A))) |
| 32 | 15, 31 | nsyl2 124 |
1
⊢ (A ∈ B → (rank ‘A) ∈ (rank
‘B)) |