Proof of Theorem rankuni2
| Step | Hyp | Ref
| Expression |
| 1 | | ranksn.1 |
. . . . 5
⊢ A ∈
V |
| 2 | 1 | uniex 2876 |
. . . 4
⊢ ∪A ∈ V |
| 3 | 2 | rankval3 4691 |
. . 3
⊢ (rank ‘∪A) = ∩{z ∈ On∣∀y ∈ ∪A(rank ‘y)
∈ z} |
| 4 | | eleq2 1538 |
. . . . . . 7
⊢ (z = ∪x ∈ A (rank ‘x) → ((rank ‘y) ∈ z ↔ (rank ‘y) ∈ ∪x ∈ A (rank
‘x))) |
| 5 | 4 | ralbidv 1666 |
. . . . . 6
⊢ (z = ∪x ∈ A (rank ‘x) → (∀y ∈ ∪A(rank ‘y)
∈ z
↔ ∀y ∈ ∪A(rank
‘y) ∈ ∪x ∈ A (rank ‘x))) |
| 6 | 5 | elrab 1908 |
. . . . 5
⊢ (∪x ∈ A (rank
‘x) ∈ {z ∈ On∣∀y ∈ ∪A(rank ‘y)
∈ z}
↔ (∪x ∈ A (rank ‘x) ∈ On ⋀ ∀y ∈ ∪A(rank
‘y) ∈ ∪x ∈ A (rank ‘x))) |
| 7 | | fvex 3738 |
. . . . . . 7
⊢ (rank ‘x) ∈
V |
| 8 | 1, 7 | iunon 3915 |
. . . . . 6
⊢ (∀x ∈ A (rank
‘x) ∈ On → ∪x ∈ A (rank
‘x) ∈ On) |
| 9 | | rankon 4681 |
. . . . . . 7
⊢ (rank ‘x) ∈ On |
| 10 | 9 | a1i 8 |
. . . . . 6
⊢ (x ∈ A → (rank ‘x) ∈ On) |
| 11 | 8, 10 | mprg 1703 |
. . . . 5
⊢ ∪x ∈ A (rank
‘x) ∈ On |
| 12 | | eluni2 2511 |
. . . . . . 7
⊢ (y ∈ ∪A ↔ ∃x ∈ A y ∈ x) |
| 13 | | ax-17 973 |
. . . . . . . . 9
⊢ (z ∈ (rank
‘y) → ∀x z ∈ (rank
‘y)) |
| 14 | | hbiu1 2588 |
. . . . . . . . 9
⊢ (z ∈ ∪x ∈ A (rank
‘x) → ∀x z ∈ ∪x ∈ A (rank
‘x)) |
| 15 | 13, 14 | hbel 1569 |
. . . . . . . 8
⊢ ((rank ‘y) ∈ ∪x ∈ A (rank
‘x) → ∀x(rank
‘y) ∈ ∪x ∈ A (rank ‘x)) |
| 16 | | ssiun2 2597 |
. . . . . . . . . 10
⊢ (x ∈ A → (rank ‘x) ⊆ ∪x ∈ A (rank
‘x)) |
| 17 | 16 | sseld 2070 |
. . . . . . . . 9
⊢ (x ∈ A → ((rank ‘y) ∈ (rank
‘x) → (rank ‘y) ∈ ∪x ∈ A (rank
‘x))) |
| 18 | | visset 1816 |
. . . . . . . . . 10
⊢ x ∈
V |
| 19 | 18 | rankel 4690 |
. . . . . . . . 9
⊢ (y ∈ x → (rank ‘y) ∈ (rank
‘x)) |
| 20 | 17, 19 | syl5 21 |
. . . . . . . 8
⊢ (x ∈ A → (y
∈ x
→ (rank ‘y) ∈ ∪x ∈ A (rank ‘x))) |
| 21 | 15, 20 | r19.23ai 1745 |
. . . . . . 7
⊢ (∃x ∈ A y ∈ x → (rank ‘y) ∈ ∪x ∈ A (rank
‘x)) |
| 22 | 12, 21 | sylbi 199 |
. . . . . 6
⊢ (y ∈ ∪A → (rank
‘y) ∈ ∪x ∈ A (rank ‘x)) |
| 23 | 22 | rgen 1701 |
. . . . 5
⊢ ∀y ∈ ∪A(rank ‘y)
∈ ∪x ∈ A (rank ‘x) |
| 24 | 6, 11, 23 | mpbir2an 732 |
. . . 4
⊢ ∪x ∈ A (rank
‘x) ∈ {z ∈ On∣∀y ∈ ∪A(rank ‘y)
∈ z} |
| 25 | | intss1 2552 |
. . . 4
⊢ (∪x ∈ A (rank
‘x) ∈ {z ∈ On∣∀y ∈ ∪A(rank ‘y)
∈ z}
→ ∩{z ∈ On∣∀y ∈ ∪A(rank ‘y)
∈ z}
⊆ ∪x ∈ A (rank
‘x)) |
| 26 | 24, 25 | ax-mp 7 |
. . 3
⊢ ∩{z ∈ On∣∀y ∈ ∪A(rank ‘y)
∈ z}
⊆ ∪x ∈ A (rank
‘x) |
| 27 | 3, 26 | eqsstr 2094 |
. 2
⊢ (rank ‘∪A) ⊆ ∪x ∈ A (rank ‘x) |
| 28 | | iunss 2595 |
. . 3
⊢ (∪x ∈ A (rank
‘x) ⊆ (rank ‘∪A) ↔ ∀x ∈ A (rank
‘x) ⊆ (rank ‘∪A)) |
| 29 | | elssuni 2530 |
. . . 4
⊢ (x ∈ A → x ⊆ ∪A) |
| 30 | 2 | rankss 4698 |
. . . 4
⊢ (x ⊆ ∪A → (rank
‘x) ⊆ (rank ‘∪A)) |
| 31 | 29, 30 | syl 10 |
. . 3
⊢ (x ∈ A → (rank ‘x) ⊆ (rank
‘∪A)) |
| 32 | 28, 31 | mprgbir 1704 |
. 2
⊢ ∪x ∈ A (rank
‘x) ⊆ (rank ‘∪A) |
| 33 | 27, 32 | eqssi 2081 |
1
⊢ (rank ‘∪A) = ∪x ∈ A (rank
‘x) |