Proof of Theorem gch2
| Step | Hyp | Ref
| Expression |
| 1 | | ssv 4008 |
. . 3
⊢ ran
ℵ ⊆ V |
| 2 | | sseq2 4010 |
. . 3
⊢ (GCH = V
→ (ran ℵ ⊆ GCH ↔ ran ℵ ⊆ V)) |
| 3 | 1, 2 | mpbiri 258 |
. 2
⊢ (GCH = V
→ ran ℵ ⊆ GCH) |
| 4 | | cardidm 9999 |
. . . . . . . 8
⊢
(card‘(card‘𝑥)) = (card‘𝑥) |
| 5 | | iscard3 10133 |
. . . . . . . 8
⊢
((card‘(card‘𝑥)) = (card‘𝑥) ↔ (card‘𝑥) ∈ (ω ∪ ran
ℵ)) |
| 6 | 4, 5 | mpbi 230 |
. . . . . . 7
⊢
(card‘𝑥)
∈ (ω ∪ ran ℵ) |
| 7 | | elun 4153 |
. . . . . . 7
⊢
((card‘𝑥)
∈ (ω ∪ ran ℵ) ↔ ((card‘𝑥) ∈ ω ∨ (card‘𝑥) ∈ ran
ℵ)) |
| 8 | 6, 7 | mpbi 230 |
. . . . . 6
⊢
((card‘𝑥)
∈ ω ∨ (card‘𝑥) ∈ ran ℵ) |
| 9 | | fingch 10663 |
. . . . . . . . 9
⊢ Fin
⊆ GCH |
| 10 | | nnfi 9207 |
. . . . . . . . 9
⊢
((card‘𝑥)
∈ ω → (card‘𝑥) ∈ Fin) |
| 11 | 9, 10 | sselid 3981 |
. . . . . . . 8
⊢
((card‘𝑥)
∈ ω → (card‘𝑥) ∈ GCH) |
| 12 | 11 | a1i 11 |
. . . . . . 7
⊢ (ran
ℵ ⊆ GCH → ((card‘𝑥) ∈ ω → (card‘𝑥) ∈ GCH)) |
| 13 | | ssel 3977 |
. . . . . . 7
⊢ (ran
ℵ ⊆ GCH → ((card‘𝑥) ∈ ran ℵ → (card‘𝑥) ∈ GCH)) |
| 14 | 12, 13 | jaod 860 |
. . . . . 6
⊢ (ran
ℵ ⊆ GCH → (((card‘𝑥) ∈ ω ∨ (card‘𝑥) ∈ ran ℵ) →
(card‘𝑥) ∈
GCH)) |
| 15 | 8, 14 | mpi 20 |
. . . . 5
⊢ (ran
ℵ ⊆ GCH → (card‘𝑥) ∈ GCH) |
| 16 | | vex 3484 |
. . . . . . 7
⊢ 𝑥 ∈ V |
| 17 | | alephon 10109 |
. . . . . . . . . . 11
⊢
(ℵ‘suc 𝑥) ∈ On |
| 18 | | simpr 484 |
. . . . . . . . . . . 12
⊢ ((ran
ℵ ⊆ GCH ∧ 𝑥
∈ On) → 𝑥 ∈
On) |
| 19 | | simpl 482 |
. . . . . . . . . . . . 13
⊢ ((ran
ℵ ⊆ GCH ∧ 𝑥
∈ On) → ran ℵ ⊆ GCH) |
| 20 | | alephfnon 10105 |
. . . . . . . . . . . . . 14
⊢ ℵ
Fn On |
| 21 | | fnfvelrn 7100 |
. . . . . . . . . . . . . 14
⊢ ((ℵ
Fn On ∧ 𝑥 ∈ On)
→ (ℵ‘𝑥)
∈ ran ℵ) |
| 22 | 20, 18, 21 | sylancr 587 |
. . . . . . . . . . . . 13
⊢ ((ran
ℵ ⊆ GCH ∧ 𝑥
∈ On) → (ℵ‘𝑥) ∈ ran ℵ) |
| 23 | 19, 22 | sseldd 3984 |
. . . . . . . . . . . 12
⊢ ((ran
ℵ ⊆ GCH ∧ 𝑥
∈ On) → (ℵ‘𝑥) ∈ GCH) |
| 24 | | onsuc 7831 |
. . . . . . . . . . . . . . 15
⊢ (𝑥 ∈ On → suc 𝑥 ∈ On) |
| 25 | 24 | adantl 481 |
. . . . . . . . . . . . . 14
⊢ ((ran
ℵ ⊆ GCH ∧ 𝑥
∈ On) → suc 𝑥
∈ On) |
| 26 | | fnfvelrn 7100 |
. . . . . . . . . . . . . 14
⊢ ((ℵ
Fn On ∧ suc 𝑥 ∈
On) → (ℵ‘suc 𝑥) ∈ ran ℵ) |
| 27 | 20, 25, 26 | sylancr 587 |
. . . . . . . . . . . . 13
⊢ ((ran
ℵ ⊆ GCH ∧ 𝑥
∈ On) → (ℵ‘suc 𝑥) ∈ ran ℵ) |
| 28 | 19, 27 | sseldd 3984 |
. . . . . . . . . . . 12
⊢ ((ran
ℵ ⊆ GCH ∧ 𝑥
∈ On) → (ℵ‘suc 𝑥) ∈ GCH) |
| 29 | | gchaleph2 10712 |
. . . . . . . . . . . 12
⊢ ((𝑥 ∈ On ∧
(ℵ‘𝑥) ∈
GCH ∧ (ℵ‘suc 𝑥) ∈ GCH) → (ℵ‘suc 𝑥) ≈ 𝒫
(ℵ‘𝑥)) |
| 30 | 18, 23, 28, 29 | syl3anc 1373 |
. . . . . . . . . . 11
⊢ ((ran
ℵ ⊆ GCH ∧ 𝑥
∈ On) → (ℵ‘suc 𝑥) ≈ 𝒫 (ℵ‘𝑥)) |
| 31 | | isnumi 9986 |
. . . . . . . . . . 11
⊢
(((ℵ‘suc 𝑥) ∈ On ∧ (ℵ‘suc 𝑥) ≈ 𝒫
(ℵ‘𝑥)) →
𝒫 (ℵ‘𝑥)
∈ dom card) |
| 32 | 17, 30, 31 | sylancr 587 |
. . . . . . . . . 10
⊢ ((ran
ℵ ⊆ GCH ∧ 𝑥
∈ On) → 𝒫 (ℵ‘𝑥) ∈ dom card) |
| 33 | 32 | ralrimiva 3146 |
. . . . . . . . 9
⊢ (ran
ℵ ⊆ GCH → ∀𝑥 ∈ On 𝒫 (ℵ‘𝑥) ∈ dom
card) |
| 34 | | dfac12 10190 |
. . . . . . . . 9
⊢
(CHOICE ↔ ∀𝑥 ∈ On 𝒫 (ℵ‘𝑥) ∈ dom
card) |
| 35 | 33, 34 | sylibr 234 |
. . . . . . . 8
⊢ (ran
ℵ ⊆ GCH → CHOICE) |
| 36 | | dfac10 10178 |
. . . . . . . 8
⊢
(CHOICE ↔ dom card = V) |
| 37 | 35, 36 | sylib 218 |
. . . . . . 7
⊢ (ran
ℵ ⊆ GCH → dom card = V) |
| 38 | 16, 37 | eleqtrrid 2848 |
. . . . . 6
⊢ (ran
ℵ ⊆ GCH → 𝑥 ∈ dom card) |
| 39 | | cardid2 9993 |
. . . . . 6
⊢ (𝑥 ∈ dom card →
(card‘𝑥) ≈
𝑥) |
| 40 | | engch 10668 |
. . . . . 6
⊢
((card‘𝑥)
≈ 𝑥 →
((card‘𝑥) ∈ GCH
↔ 𝑥 ∈
GCH)) |
| 41 | 38, 39, 40 | 3syl 18 |
. . . . 5
⊢ (ran
ℵ ⊆ GCH → ((card‘𝑥) ∈ GCH ↔ 𝑥 ∈ GCH)) |
| 42 | 15, 41 | mpbid 232 |
. . . 4
⊢ (ran
ℵ ⊆ GCH → 𝑥 ∈ GCH) |
| 43 | 16 | a1i 11 |
. . . 4
⊢ (ran
ℵ ⊆ GCH → 𝑥 ∈ V) |
| 44 | 42, 43 | 2thd 265 |
. . 3
⊢ (ran
ℵ ⊆ GCH → (𝑥 ∈ GCH ↔ 𝑥 ∈ V)) |
| 45 | 44 | eqrdv 2735 |
. 2
⊢ (ran
ℵ ⊆ GCH → GCH = V) |
| 46 | 3, 45 | impbii 209 |
1
⊢ (GCH = V
↔ ran ℵ ⊆ GCH) |