Proof of Theorem j0ltaleph
| Step | Hyp | Ref
| Expression |
| 1 | | omelon 9648 |
. . . . . . . . 9
⊢ ω
∈ On |
| 2 | | j0iso 35936 |
. . . . . . . . . . 11
⊢
𝐽0 Isom 𝑅0, E ((On × On),
On) |
| 3 | | isof1o 7331 |
. . . . . . . . . . 11
⊢
(𝐽0 Isom 𝑅0, E ((On × On),
On) → 𝐽0:(On × On)–1-1-onto→On) |
| 4 | | f1of 6824 |
. . . . . . . . . . 11
⊢
(𝐽0:(On × On)–1-1-onto→On
→ 𝐽0:(On × On)⟶On) |
| 5 | 2, 3, 4 | mp2b 10 |
. . . . . . . . . 10
⊢
𝐽0:(On × On)⟶On |
| 6 | | 0elon 6418 |
. . . . . . . . . 10
⊢ ∅
∈ On |
| 7 | 5, 6 | f0cli 7098 |
. . . . . . . . 9
⊢
(𝐽0‘〈𝐴, 𝐵〉) ∈ On |
| 8 | | domtriord 9143 |
. . . . . . . . 9
⊢ ((ω
∈ On ∧ (𝐽0‘〈𝐴, 𝐵〉) ∈ On) → (ω ≼
(𝐽0‘〈𝐴, 𝐵〉) ↔ ¬
(𝐽0‘〈𝐴, 𝐵〉) ≺ ω)) |
| 9 | 1, 7, 8 | mp2an 705 |
. . . . . . . 8
⊢ (ω
≼ (𝐽0‘〈𝐴, 𝐵〉) ↔ ¬
(𝐽0‘〈𝐴, 𝐵〉) ≺ ω) |
| 10 | 9 | con2bii 360 |
. . . . . . 7
⊢
((𝐽0‘〈𝐴, 𝐵〉) ≺ ω ↔ ¬ ω
≼ (𝐽0‘〈𝐴, 𝐵〉)) |
| 11 | | sdomel 9144 |
. . . . . . . 8
⊢
(((𝐽0‘〈𝐴, 𝐵〉) ∈ On ∧ ω ∈ On)
→ ((𝐽0‘〈𝐴, 𝐵〉) ≺ ω →
(𝐽0‘〈𝐴, 𝐵〉) ∈ ω)) |
| 12 | 7, 1, 11 | mp2an 705 |
. . . . . . 7
⊢
((𝐽0‘〈𝐴, 𝐵〉) ≺ ω →
(𝐽0‘〈𝐴, 𝐵〉) ∈ ω) |
| 13 | 10, 12 | sylbir 238 |
. . . . . 6
⊢ (¬
ω ≼ (𝐽0‘〈𝐴, 𝐵〉) →
(𝐽0‘〈𝐴, 𝐵〉) ∈ ω) |
| 14 | 13 | orri 876 |
. . . . 5
⊢ (ω
≼ (𝐽0‘〈𝐴, 𝐵〉) ∨
(𝐽0‘〈𝐴, 𝐵〉) ∈ ω) |
| 15 | | alephon 10149 |
. . . . . . . . . . . 12
⊢
(ℵ‘𝐶)
∈ On |
| 16 | 15 | oneli 6478 |
. . . . . . . . . . 11
⊢ (𝐴 ∈ (ℵ‘𝐶) → 𝐴 ∈ On) |
| 17 | 15 | oneli 6478 |
. . . . . . . . . . 11
⊢ (𝐵 ∈ (ℵ‘𝐶) → 𝐵 ∈ On) |
| 18 | 16, 17 | anim12i 625 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶)) → (𝐴 ∈ On ∧ 𝐵 ∈ On)) |
| 19 | 18 | 3adant3 1150 |
. . . . . . . . 9
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶) ∧ 𝐶 ∈ On) → (𝐴 ∈ On ∧ 𝐵 ∈ On)) |
| 20 | | j0ltalephlem 35939 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) →
(𝐽0‘〈𝐴, 𝐵〉) ≼ (suc (𝐴 ∪ 𝐵) × suc (𝐴 ∪ 𝐵))) |
| 21 | | xpfi 9312 |
. . . . . . . . . . . . . . 15
⊢ ((suc
(𝐴 ∪ 𝐵) ∈ Fin ∧ suc (𝐴 ∪ 𝐵) ∈ Fin) → (suc (𝐴 ∪ 𝐵) × suc (𝐴 ∪ 𝐵)) ∈ Fin) |
| 22 | 21 | anidms 577 |
. . . . . . . . . . . . . 14
⊢ (suc
(𝐴 ∪ 𝐵) ∈ Fin → (suc (𝐴 ∪ 𝐵) × suc (𝐴 ∪ 𝐵)) ∈ Fin) |
| 23 | | domfi 9205 |
. . . . . . . . . . . . . 14
⊢ (((suc
(𝐴 ∪ 𝐵) × suc (𝐴 ∪ 𝐵)) ∈ Fin ∧
(𝐽0‘〈𝐴, 𝐵〉) ≼ (suc (𝐴 ∪ 𝐵) × suc (𝐴 ∪ 𝐵))) →
(𝐽0‘〈𝐴, 𝐵〉) ∈ Fin) |
| 24 | 22, 23 | sylan 592 |
. . . . . . . . . . . . 13
⊢ ((suc
(𝐴 ∪ 𝐵) ∈ Fin ∧
(𝐽0‘〈𝐴, 𝐵〉) ≼ (suc (𝐴 ∪ 𝐵) × suc (𝐴 ∪ 𝐵))) →
(𝐽0‘〈𝐴, 𝐵〉) ∈ Fin) |
| 25 | 24 | expcom 419 |
. . . . . . . . . . . 12
⊢
((𝐽0‘〈𝐴, 𝐵〉) ≼ (suc (𝐴 ∪ 𝐵) × suc (𝐴 ∪ 𝐵)) → (suc (𝐴 ∪ 𝐵) ∈ Fin →
(𝐽0‘〈𝐴, 𝐵〉) ∈ Fin)) |
| 26 | 20, 25 | syl 18 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (suc (𝐴 ∪ 𝐵) ∈ Fin →
(𝐽0‘〈𝐴, 𝐵〉) ∈ Fin)) |
| 27 | | onenon 10031 |
. . . . . . . . . . . . 13
⊢
((𝐽0‘〈𝐴, 𝐵〉) ∈ On →
(𝐽0‘〈𝐴, 𝐵〉) ∈ dom card) |
| 28 | | infinfnum 35806 |
. . . . . . . . . . . . 13
⊢
((𝐽0‘〈𝐴, 𝐵〉) ∈ dom card → (¬
(𝐽0‘〈𝐴, 𝐵〉) ∈ Fin ↔ ω ≼
(𝐽0‘〈𝐴, 𝐵〉))) |
| 29 | 7, 27, 28 | mp2b 10 |
. . . . . . . . . . . 12
⊢ (¬
(𝐽0‘〈𝐴, 𝐵〉) ∈ Fin ↔ ω ≼
(𝐽0‘〈𝐴, 𝐵〉)) |
| 30 | 29 | biimpri 231 |
. . . . . . . . . . 11
⊢ (ω
≼ (𝐽0‘〈𝐴, 𝐵〉) → ¬
(𝐽0‘〈𝐴, 𝐵〉) ∈ Fin) |
| 31 | 26, 30 | nsyli 158 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (ω
≼ (𝐽0‘〈𝐴, 𝐵〉) → ¬ suc (𝐴 ∪ 𝐵) ∈ Fin)) |
| 32 | | onun2 6473 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 ∪ 𝐵) ∈ On) |
| 33 | | onsuc 7824 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∪ 𝐵) ∈ On → suc (𝐴 ∪ 𝐵) ∈ On) |
| 34 | | onenon 10031 |
. . . . . . . . . . . 12
⊢ (suc
(𝐴 ∪ 𝐵) ∈ On → suc (𝐴 ∪ 𝐵) ∈ dom card) |
| 35 | 32, 33, 34 | 3syl 19 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → suc (𝐴 ∪ 𝐵) ∈ dom card) |
| 36 | | infinfnum 35806 |
. . . . . . . . . . 11
⊢ (suc
(𝐴 ∪ 𝐵) ∈ dom card → (¬ suc (𝐴 ∪ 𝐵) ∈ Fin ↔ ω ≼ suc
(𝐴 ∪ 𝐵))) |
| 37 | 35, 36 | syl 18 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (¬ suc
(𝐴 ∪ 𝐵) ∈ Fin ↔ ω ≼ suc
(𝐴 ∪ 𝐵))) |
| 38 | 31, 37 | sylibd 242 |
. . . . . . . . 9
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (ω
≼ (𝐽0‘〈𝐴, 𝐵〉) → ω ≼ suc (𝐴 ∪ 𝐵))) |
| 39 | 19, 38 | syl 18 |
. . . . . . . 8
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶) ∧ 𝐶 ∈ On) → (ω ≼
(𝐽0‘〈𝐴, 𝐵〉) → ω ≼ suc (𝐴 ∪ 𝐵))) |
| 40 | | infxpidm2 10097 |
. . . . . . . . . . . . . 14
⊢ ((suc
(𝐴 ∪ 𝐵) ∈ dom card ∧ ω ≼ suc
(𝐴 ∪ 𝐵)) → (suc (𝐴 ∪ 𝐵) × suc (𝐴 ∪ 𝐵)) ≈ suc (𝐴 ∪ 𝐵)) |
| 41 | 35, 40 | sylan 592 |
. . . . . . . . . . . . 13
⊢ (((𝐴 ∈ On ∧ 𝐵 ∈ On) ∧ ω
≼ suc (𝐴 ∪ 𝐵)) → (suc (𝐴 ∪ 𝐵) × suc (𝐴 ∪ 𝐵)) ≈ suc (𝐴 ∪ 𝐵)) |
| 42 | 41 | ex 418 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (ω
≼ suc (𝐴 ∪ 𝐵) → (suc (𝐴 ∪ 𝐵) × suc (𝐴 ∪ 𝐵)) ≈ suc (𝐴 ∪ 𝐵))) |
| 43 | | domentr 9041 |
. . . . . . . . . . . 12
⊢
(((𝐽0‘〈𝐴, 𝐵〉) ≼ (suc (𝐴 ∪ 𝐵) × suc (𝐴 ∪ 𝐵)) ∧ (suc (𝐴 ∪ 𝐵) × suc (𝐴 ∪ 𝐵)) ≈ suc (𝐴 ∪ 𝐵)) →
(𝐽0‘〈𝐴, 𝐵〉) ≼ suc (𝐴 ∪ 𝐵)) |
| 44 | 20, 42, 43 | syl6an 697 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (ω
≼ suc (𝐴 ∪ 𝐵) →
(𝐽0‘〈𝐴, 𝐵〉) ≼ suc (𝐴 ∪ 𝐵))) |
| 45 | 19, 44 | syl 18 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶) ∧ 𝐶 ∈ On) → (ω ≼ suc
(𝐴 ∪ 𝐵) →
(𝐽0‘〈𝐴, 𝐵〉) ≼ suc (𝐴 ∪ 𝐵))) |
| 46 | | onunel 6470 |
. . . . . . . . . . . . . . . 16
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On ∧
(ℵ‘𝐶) ∈
On) → ((𝐴 ∪ 𝐵) ∈ (ℵ‘𝐶) ↔ (𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶)))) |
| 47 | 15, 46 | mp3an3 1479 |
. . . . . . . . . . . . . . 15
⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → ((𝐴 ∪ 𝐵) ∈ (ℵ‘𝐶) ↔ (𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶)))) |
| 48 | 16, 17, 47 | syl2an 608 |
. . . . . . . . . . . . . 14
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶)) → ((𝐴 ∪ 𝐵) ∈ (ℵ‘𝐶) ↔ (𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶)))) |
| 49 | 48 | ibir 271 |
. . . . . . . . . . . . 13
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶)) → (𝐴 ∪ 𝐵) ∈ (ℵ‘𝐶)) |
| 50 | 49 | 3adant3 1150 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶) ∧ 𝐶 ∈ On) → (𝐴 ∪ 𝐵) ∈ (ℵ‘𝐶)) |
| 51 | | alephislim 10163 |
. . . . . . . . . . . . . 14
⊢ (𝐶 ∈ On ↔ Lim
(ℵ‘𝐶)) |
| 52 | | limsuc 7860 |
. . . . . . . . . . . . . 14
⊢ (Lim
(ℵ‘𝐶) →
((𝐴 ∪ 𝐵) ∈ (ℵ‘𝐶) ↔ suc (𝐴 ∪ 𝐵) ∈ (ℵ‘𝐶))) |
| 53 | 51, 52 | sylbi 220 |
. . . . . . . . . . . . 13
⊢ (𝐶 ∈ On → ((𝐴 ∪ 𝐵) ∈ (ℵ‘𝐶) ↔ suc (𝐴 ∪ 𝐵) ∈ (ℵ‘𝐶))) |
| 54 | 53 | 3ad2ant3 1153 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶) ∧ 𝐶 ∈ On) → ((𝐴 ∪ 𝐵) ∈ (ℵ‘𝐶) ↔ suc (𝐴 ∪ 𝐵) ∈ (ℵ‘𝐶))) |
| 55 | 50, 54 | mpbid 235 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶) ∧ 𝐶 ∈ On) → suc (𝐴 ∪ 𝐵) ∈ (ℵ‘𝐶)) |
| 56 | 18, 32, 33 | 3syl 19 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶)) → suc (𝐴 ∪ 𝐵) ∈ On) |
| 57 | | alephsdom 10166 |
. . . . . . . . . . . 12
⊢ ((suc
(𝐴 ∪ 𝐵) ∈ On ∧ 𝐶 ∈ On) → (suc (𝐴 ∪ 𝐵) ∈ (ℵ‘𝐶) ↔ suc (𝐴 ∪ 𝐵) ≺ (ℵ‘𝐶))) |
| 58 | 56, 57 | stoic3 1808 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶) ∧ 𝐶 ∈ On) → (suc (𝐴 ∪ 𝐵) ∈ (ℵ‘𝐶) ↔ suc (𝐴 ∪ 𝐵) ≺ (ℵ‘𝐶))) |
| 59 | 55, 58 | mpbid 235 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶) ∧ 𝐶 ∈ On) → suc (𝐴 ∪ 𝐵) ≺ (ℵ‘𝐶)) |
| 60 | 45, 59 | jctird 536 |
. . . . . . . . 9
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶) ∧ 𝐶 ∈ On) → (ω ≼ suc
(𝐴 ∪ 𝐵) →
((𝐽0‘〈𝐴, 𝐵〉) ≼ suc (𝐴 ∪ 𝐵) ∧ suc (𝐴 ∪ 𝐵) ≺ (ℵ‘𝐶)))) |
| 61 | | domsdomtr 9132 |
. . . . . . . . 9
⊢
(((𝐽0‘〈𝐴, 𝐵〉) ≼ suc (𝐴 ∪ 𝐵) ∧ suc (𝐴 ∪ 𝐵) ≺ (ℵ‘𝐶)) →
(𝐽0‘〈𝐴, 𝐵〉) ≺ (ℵ‘𝐶)) |
| 62 | 60, 61 | syl6 36 |
. . . . . . . 8
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶) ∧ 𝐶 ∈ On) → (ω ≼ suc
(𝐴 ∪ 𝐵) →
(𝐽0‘〈𝐴, 𝐵〉) ≺ (ℵ‘𝐶))) |
| 63 | 39, 62 | syld 48 |
. . . . . . 7
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶) ∧ 𝐶 ∈ On) → (ω ≼
(𝐽0‘〈𝐴, 𝐵〉) →
(𝐽0‘〈𝐴, 𝐵〉) ≺ (ℵ‘𝐶))) |
| 64 | | alephsdom 10166 |
. . . . . . . . 9
⊢
(((𝐽0‘〈𝐴, 𝐵〉) ∈ On ∧ 𝐶 ∈ On) →
((𝐽0‘〈𝐴, 𝐵〉) ∈ (ℵ‘𝐶) ↔
(𝐽0‘〈𝐴, 𝐵〉) ≺ (ℵ‘𝐶))) |
| 65 | 7, 64 | mpan 703 |
. . . . . . . 8
⊢ (𝐶 ∈ On →
((𝐽0‘〈𝐴, 𝐵〉) ∈ (ℵ‘𝐶) ↔
(𝐽0‘〈𝐴, 𝐵〉) ≺ (ℵ‘𝐶))) |
| 66 | 65 | 3ad2ant3 1153 |
. . . . . . 7
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶) ∧ 𝐶 ∈ On) →
((𝐽0‘〈𝐴, 𝐵〉) ∈ (ℵ‘𝐶) ↔
(𝐽0‘〈𝐴, 𝐵〉) ≺ (ℵ‘𝐶))) |
| 67 | 63, 66 | sylibrd 262 |
. . . . . 6
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶) ∧ 𝐶 ∈ On) → (ω ≼
(𝐽0‘〈𝐴, 𝐵〉) →
(𝐽0‘〈𝐴, 𝐵〉) ∈ (ℵ‘𝐶))) |
| 68 | | alephgeom 10162 |
. . . . . . . . . 10
⊢ (𝐶 ∈ On ↔ ω
⊆ (ℵ‘𝐶)) |
| 69 | 68 | biimpi 219 |
. . . . . . . . 9
⊢ (𝐶 ∈ On → ω
⊆ (ℵ‘𝐶)) |
| 70 | 69 | sselda 3908 |
. . . . . . . 8
⊢ ((𝐶 ∈ On ∧
(𝐽0‘〈𝐴, 𝐵〉) ∈ ω) →
(𝐽0‘〈𝐴, 𝐵〉) ∈ (ℵ‘𝐶)) |
| 71 | 70 | 3ad2antl3 1206 |
. . . . . . 7
⊢ (((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶) ∧ 𝐶 ∈ On) ∧
(𝐽0‘〈𝐴, 𝐵〉) ∈ ω) →
(𝐽0‘〈𝐴, 𝐵〉) ∈ (ℵ‘𝐶)) |
| 72 | 71 | ex 418 |
. . . . . 6
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶) ∧ 𝐶 ∈ On) →
((𝐽0‘〈𝐴, 𝐵〉) ∈ ω →
(𝐽0‘〈𝐴, 𝐵〉) ∈ (ℵ‘𝐶))) |
| 73 | 67, 72 | jaod 873 |
. . . . 5
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶) ∧ 𝐶 ∈ On) → ((ω ≼
(𝐽0‘〈𝐴, 𝐵〉) ∨
(𝐽0‘〈𝐴, 𝐵〉) ∈ ω) →
(𝐽0‘〈𝐴, 𝐵〉) ∈ (ℵ‘𝐶))) |
| 74 | 14, 73 | mpi 21 |
. . . 4
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶) ∧ 𝐶 ∈ On) →
(𝐽0‘〈𝐴, 𝐵〉) ∈ (ℵ‘𝐶)) |
| 75 | 74 | 3expia 1139 |
. . 3
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶)) → (𝐶 ∈ On →
(𝐽0‘〈𝐴, 𝐵〉) ∈ (ℵ‘𝐶))) |
| 76 | 75 | com12 33 |
. 2
⊢ (𝐶 ∈ On → ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶)) →
(𝐽0‘〈𝐴, 𝐵〉) ∈ (ℵ‘𝐶))) |
| 77 | | alephfnon 10145 |
. . . . . . . 8
⊢ ℵ
Fn On |
| 78 | 77 | fndmi 6643 |
. . . . . . 7
⊢ dom
ℵ = On |
| 79 | 78 | eleq2i 2852 |
. . . . . 6
⊢ (𝐶 ∈ dom ℵ ↔ 𝐶 ∈ On) |
| 80 | | ndmfv 6917 |
. . . . . 6
⊢ (¬
𝐶 ∈ dom ℵ →
(ℵ‘𝐶) =
∅) |
| 81 | 79, 80 | sylnbir 334 |
. . . . 5
⊢ (¬
𝐶 ∈ On →
(ℵ‘𝐶) =
∅) |
| 82 | | nel02 4284 |
. . . . 5
⊢
((ℵ‘𝐶) =
∅ → ¬ 𝐴
∈ (ℵ‘𝐶)) |
| 83 | 81, 82 | syl 18 |
. . . 4
⊢ (¬
𝐶 ∈ On → ¬
𝐴 ∈
(ℵ‘𝐶)) |
| 84 | 83 | intnanrd 495 |
. . 3
⊢ (¬
𝐶 ∈ On → ¬
(𝐴 ∈
(ℵ‘𝐶) ∧
𝐵 ∈
(ℵ‘𝐶))) |
| 85 | 84 | pm2.21d 122 |
. 2
⊢ (¬
𝐶 ∈ On → ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶)) →
(𝐽0‘〈𝐴, 𝐵〉) ∈ (ℵ‘𝐶))) |
| 86 | 76, 85 | pm2.61i 184 |
1
⊢ ((𝐴 ∈ (ℵ‘𝐶) ∧ 𝐵 ∈ (ℵ‘𝐶)) →
(𝐽0‘〈𝐴, 𝐵〉) ∈ (ℵ‘𝐶)) |