| Step | Hyp | Ref
| Expression |
| 1 | | nn0ennn 10525 |
. . . 4
⊢
ℕ0 ≈ ℕ |
| 2 | 1 | ensymi 6841 |
. . 3
⊢ ℕ
≈ ℕ0 |
| 3 | | entr 6843 |
. . 3
⊢ ((𝐴 ≈ ℕ ∧ ℕ
≈ ℕ0) → 𝐴 ≈
ℕ0) |
| 4 | 2, 3 | mpan2 425 |
. 2
⊢ (𝐴 ≈ ℕ → 𝐴 ≈
ℕ0) |
| 5 | | bren 6806 |
. . . 4
⊢ (𝐴 ≈ ℕ0
↔ ∃𝑔 𝑔:𝐴–1-1-onto→ℕ0) |
| 6 | 5 | biimpi 120 |
. . 3
⊢ (𝐴 ≈ ℕ0
→ ∃𝑔 𝑔:𝐴–1-1-onto→ℕ0) |
| 7 | | f1of 5504 |
. . . . . . . . . . 11
⊢ (𝑔:𝐴–1-1-onto→ℕ0 → 𝑔:𝐴⟶ℕ0) |
| 8 | 7 | adantr 276 |
. . . . . . . . . 10
⊢ ((𝑔:𝐴–1-1-onto→ℕ0 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴)) → 𝑔:𝐴⟶ℕ0) |
| 9 | | simprl 529 |
. . . . . . . . . 10
⊢ ((𝑔:𝐴–1-1-onto→ℕ0 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴)) → 𝑥 ∈ 𝐴) |
| 10 | 8, 9 | ffvelcdmd 5698 |
. . . . . . . . 9
⊢ ((𝑔:𝐴–1-1-onto→ℕ0 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴)) → (𝑔‘𝑥) ∈
ℕ0) |
| 11 | 10 | nn0zd 9446 |
. . . . . . . 8
⊢ ((𝑔:𝐴–1-1-onto→ℕ0 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴)) → (𝑔‘𝑥) ∈ ℤ) |
| 12 | | simprr 531 |
. . . . . . . . . 10
⊢ ((𝑔:𝐴–1-1-onto→ℕ0 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴)) → 𝑦 ∈ 𝐴) |
| 13 | 8, 12 | ffvelcdmd 5698 |
. . . . . . . . 9
⊢ ((𝑔:𝐴–1-1-onto→ℕ0 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴)) → (𝑔‘𝑦) ∈
ℕ0) |
| 14 | 13 | nn0zd 9446 |
. . . . . . . 8
⊢ ((𝑔:𝐴–1-1-onto→ℕ0 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴)) → (𝑔‘𝑦) ∈ ℤ) |
| 15 | | zdceq 9401 |
. . . . . . . 8
⊢ (((𝑔‘𝑥) ∈ ℤ ∧ (𝑔‘𝑦) ∈ ℤ) → DECID
(𝑔‘𝑥) = (𝑔‘𝑦)) |
| 16 | 11, 14, 15 | syl2anc 411 |
. . . . . . 7
⊢ ((𝑔:𝐴–1-1-onto→ℕ0 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴)) → DECID (𝑔‘𝑥) = (𝑔‘𝑦)) |
| 17 | | dff1o6 5823 |
. . . . . . . . . . . . 13
⊢ (𝑔:𝐴–1-1-onto→ℕ0 ↔ (𝑔 Fn 𝐴 ∧ ran 𝑔 = ℕ0 ∧ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ((𝑔‘𝑥) = (𝑔‘𝑦) → 𝑥 = 𝑦))) |
| 18 | 17 | simp3bi 1016 |
. . . . . . . . . . . 12
⊢ (𝑔:𝐴–1-1-onto→ℕ0 → ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ((𝑔‘𝑥) = (𝑔‘𝑦) → 𝑥 = 𝑦)) |
| 19 | 18 | r19.21bi 2585 |
. . . . . . . . . . 11
⊢ ((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑥 ∈ 𝐴) → ∀𝑦 ∈ 𝐴 ((𝑔‘𝑥) = (𝑔‘𝑦) → 𝑥 = 𝑦)) |
| 20 | 19 | r19.21bi 2585 |
. . . . . . . . . 10
⊢ (((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑥 ∈ 𝐴) ∧ 𝑦 ∈ 𝐴) → ((𝑔‘𝑥) = (𝑔‘𝑦) → 𝑥 = 𝑦)) |
| 21 | 20 | anasss 399 |
. . . . . . . . 9
⊢ ((𝑔:𝐴–1-1-onto→ℕ0 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴)) → ((𝑔‘𝑥) = (𝑔‘𝑦) → 𝑥 = 𝑦)) |
| 22 | | fveq2 5558 |
. . . . . . . . 9
⊢ (𝑥 = 𝑦 → (𝑔‘𝑥) = (𝑔‘𝑦)) |
| 23 | 21, 22 | impbid1 142 |
. . . . . . . 8
⊢ ((𝑔:𝐴–1-1-onto→ℕ0 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴)) → ((𝑔‘𝑥) = (𝑔‘𝑦) ↔ 𝑥 = 𝑦)) |
| 24 | 23 | dcbid 839 |
. . . . . . 7
⊢ ((𝑔:𝐴–1-1-onto→ℕ0 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴)) → (DECID (𝑔‘𝑥) = (𝑔‘𝑦) ↔ DECID 𝑥 = 𝑦)) |
| 25 | 16, 24 | mpbid 147 |
. . . . . 6
⊢ ((𝑔:𝐴–1-1-onto→ℕ0 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐴)) → DECID 𝑥 = 𝑦) |
| 26 | 25 | ralrimivva 2579 |
. . . . 5
⊢ (𝑔:𝐴–1-1-onto→ℕ0 → ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 DECID 𝑥 = 𝑦) |
| 27 | | f1ocnv 5517 |
. . . . . . 7
⊢ (𝑔:𝐴–1-1-onto→ℕ0 → ◡𝑔:ℕ0–1-1-onto→𝐴) |
| 28 | | f1ofo 5511 |
. . . . . . 7
⊢ (◡𝑔:ℕ0–1-1-onto→𝐴 → ◡𝑔:ℕ0–onto→𝐴) |
| 29 | 27, 28 | syl 14 |
. . . . . 6
⊢ (𝑔:𝐴–1-1-onto→ℕ0 → ◡𝑔:ℕ0–onto→𝐴) |
| 30 | | peano2nn0 9289 |
. . . . . . . . 9
⊢ (𝑛 ∈ ℕ0
→ (𝑛 + 1) ∈
ℕ0) |
| 31 | 30 | adantl 277 |
. . . . . . . 8
⊢ ((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑛 ∈ ℕ0) → (𝑛 + 1) ∈
ℕ0) |
| 32 | | elfznn0 10189 |
. . . . . . . . . . . . . . 15
⊢ (𝑗 ∈ (0...𝑛) → 𝑗 ∈ ℕ0) |
| 33 | 32 | adantl 277 |
. . . . . . . . . . . . . 14
⊢ (((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑛 ∈ ℕ0) ∧ 𝑗 ∈ (0...𝑛)) → 𝑗 ∈ ℕ0) |
| 34 | 33 | nn0red 9303 |
. . . . . . . . . . . . 13
⊢ (((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑛 ∈ ℕ0) ∧ 𝑗 ∈ (0...𝑛)) → 𝑗 ∈ ℝ) |
| 35 | | elfzle2 10103 |
. . . . . . . . . . . . . . 15
⊢ (𝑗 ∈ (0...𝑛) → 𝑗 ≤ 𝑛) |
| 36 | 35 | adantl 277 |
. . . . . . . . . . . . . 14
⊢ (((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑛 ∈ ℕ0) ∧ 𝑗 ∈ (0...𝑛)) → 𝑗 ≤ 𝑛) |
| 37 | | simplr 528 |
. . . . . . . . . . . . . . 15
⊢ (((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑛 ∈ ℕ0) ∧ 𝑗 ∈ (0...𝑛)) → 𝑛 ∈ ℕ0) |
| 38 | | nn0leltp1 9389 |
. . . . . . . . . . . . . . 15
⊢ ((𝑗 ∈ ℕ0
∧ 𝑛 ∈
ℕ0) → (𝑗 ≤ 𝑛 ↔ 𝑗 < (𝑛 + 1))) |
| 39 | 33, 37, 38 | syl2anc 411 |
. . . . . . . . . . . . . 14
⊢ (((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑛 ∈ ℕ0) ∧ 𝑗 ∈ (0...𝑛)) → (𝑗 ≤ 𝑛 ↔ 𝑗 < (𝑛 + 1))) |
| 40 | 36, 39 | mpbid 147 |
. . . . . . . . . . . . 13
⊢ (((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑛 ∈ ℕ0) ∧ 𝑗 ∈ (0...𝑛)) → 𝑗 < (𝑛 + 1)) |
| 41 | 34, 40 | gtned 8139 |
. . . . . . . . . . . 12
⊢ (((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑛 ∈ ℕ0) ∧ 𝑗 ∈ (0...𝑛)) → (𝑛 + 1) ≠ 𝑗) |
| 42 | 41 | neneqd 2388 |
. . . . . . . . . . 11
⊢ (((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑛 ∈ ℕ0) ∧ 𝑗 ∈ (0...𝑛)) → ¬ (𝑛 + 1) = 𝑗) |
| 43 | | dff1o6 5823 |
. . . . . . . . . . . . . . 15
⊢ (◡𝑔:ℕ0–1-1-onto→𝐴 ↔ (◡𝑔 Fn ℕ0 ∧ ran ◡𝑔 = 𝐴 ∧ ∀𝑥 ∈ ℕ0 ∀𝑦 ∈ ℕ0
((◡𝑔‘𝑥) = (◡𝑔‘𝑦) → 𝑥 = 𝑦))) |
| 44 | 27, 43 | sylib 122 |
. . . . . . . . . . . . . 14
⊢ (𝑔:𝐴–1-1-onto→ℕ0 → (◡𝑔 Fn ℕ0 ∧ ran ◡𝑔 = 𝐴 ∧ ∀𝑥 ∈ ℕ0 ∀𝑦 ∈ ℕ0
((◡𝑔‘𝑥) = (◡𝑔‘𝑦) → 𝑥 = 𝑦))) |
| 45 | 44 | simp3d 1013 |
. . . . . . . . . . . . 13
⊢ (𝑔:𝐴–1-1-onto→ℕ0 → ∀𝑥 ∈ ℕ0
∀𝑦 ∈
ℕ0 ((◡𝑔‘𝑥) = (◡𝑔‘𝑦) → 𝑥 = 𝑦)) |
| 46 | 45 | ad2antrr 488 |
. . . . . . . . . . . 12
⊢ (((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑛 ∈ ℕ0) ∧ 𝑗 ∈ (0...𝑛)) → ∀𝑥 ∈ ℕ0 ∀𝑦 ∈ ℕ0
((◡𝑔‘𝑥) = (◡𝑔‘𝑦) → 𝑥 = 𝑦)) |
| 47 | 31 | adantr 276 |
. . . . . . . . . . . . 13
⊢ (((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑛 ∈ ℕ0) ∧ 𝑗 ∈ (0...𝑛)) → (𝑛 + 1) ∈
ℕ0) |
| 48 | | fveqeq2 5567 |
. . . . . . . . . . . . . . 15
⊢ (𝑥 = (𝑛 + 1) → ((◡𝑔‘𝑥) = (◡𝑔‘𝑦) ↔ (◡𝑔‘(𝑛 + 1)) = (◡𝑔‘𝑦))) |
| 49 | | eqeq1 2203 |
. . . . . . . . . . . . . . 15
⊢ (𝑥 = (𝑛 + 1) → (𝑥 = 𝑦 ↔ (𝑛 + 1) = 𝑦)) |
| 50 | 48, 49 | imbi12d 234 |
. . . . . . . . . . . . . 14
⊢ (𝑥 = (𝑛 + 1) → (((◡𝑔‘𝑥) = (◡𝑔‘𝑦) → 𝑥 = 𝑦) ↔ ((◡𝑔‘(𝑛 + 1)) = (◡𝑔‘𝑦) → (𝑛 + 1) = 𝑦))) |
| 51 | | fveq2 5558 |
. . . . . . . . . . . . . . . 16
⊢ (𝑦 = 𝑗 → (◡𝑔‘𝑦) = (◡𝑔‘𝑗)) |
| 52 | 51 | eqeq2d 2208 |
. . . . . . . . . . . . . . 15
⊢ (𝑦 = 𝑗 → ((◡𝑔‘(𝑛 + 1)) = (◡𝑔‘𝑦) ↔ (◡𝑔‘(𝑛 + 1)) = (◡𝑔‘𝑗))) |
| 53 | | eqeq2 2206 |
. . . . . . . . . . . . . . 15
⊢ (𝑦 = 𝑗 → ((𝑛 + 1) = 𝑦 ↔ (𝑛 + 1) = 𝑗)) |
| 54 | 52, 53 | imbi12d 234 |
. . . . . . . . . . . . . 14
⊢ (𝑦 = 𝑗 → (((◡𝑔‘(𝑛 + 1)) = (◡𝑔‘𝑦) → (𝑛 + 1) = 𝑦) ↔ ((◡𝑔‘(𝑛 + 1)) = (◡𝑔‘𝑗) → (𝑛 + 1) = 𝑗))) |
| 55 | 50, 54 | rspc2v 2881 |
. . . . . . . . . . . . 13
⊢ (((𝑛 + 1) ∈ ℕ0
∧ 𝑗 ∈
ℕ0) → (∀𝑥 ∈ ℕ0 ∀𝑦 ∈ ℕ0
((◡𝑔‘𝑥) = (◡𝑔‘𝑦) → 𝑥 = 𝑦) → ((◡𝑔‘(𝑛 + 1)) = (◡𝑔‘𝑗) → (𝑛 + 1) = 𝑗))) |
| 56 | 47, 33, 55 | syl2anc 411 |
. . . . . . . . . . . 12
⊢ (((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑛 ∈ ℕ0) ∧ 𝑗 ∈ (0...𝑛)) → (∀𝑥 ∈ ℕ0 ∀𝑦 ∈ ℕ0
((◡𝑔‘𝑥) = (◡𝑔‘𝑦) → 𝑥 = 𝑦) → ((◡𝑔‘(𝑛 + 1)) = (◡𝑔‘𝑗) → (𝑛 + 1) = 𝑗))) |
| 57 | 46, 56 | mpd 13 |
. . . . . . . . . . 11
⊢ (((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑛 ∈ ℕ0) ∧ 𝑗 ∈ (0...𝑛)) → ((◡𝑔‘(𝑛 + 1)) = (◡𝑔‘𝑗) → (𝑛 + 1) = 𝑗)) |
| 58 | 42, 57 | mtod 664 |
. . . . . . . . . 10
⊢ (((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑛 ∈ ℕ0) ∧ 𝑗 ∈ (0...𝑛)) → ¬ (◡𝑔‘(𝑛 + 1)) = (◡𝑔‘𝑗)) |
| 59 | 58 | neqned 2374 |
. . . . . . . . 9
⊢ (((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑛 ∈ ℕ0) ∧ 𝑗 ∈ (0...𝑛)) → (◡𝑔‘(𝑛 + 1)) ≠ (◡𝑔‘𝑗)) |
| 60 | 59 | ralrimiva 2570 |
. . . . . . . 8
⊢ ((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑛 ∈ ℕ0) →
∀𝑗 ∈ (0...𝑛)(◡𝑔‘(𝑛 + 1)) ≠ (◡𝑔‘𝑗)) |
| 61 | | fveq2 5558 |
. . . . . . . . . . 11
⊢ (𝑘 = (𝑛 + 1) → (◡𝑔‘𝑘) = (◡𝑔‘(𝑛 + 1))) |
| 62 | 61 | neeq1d 2385 |
. . . . . . . . . 10
⊢ (𝑘 = (𝑛 + 1) → ((◡𝑔‘𝑘) ≠ (◡𝑔‘𝑗) ↔ (◡𝑔‘(𝑛 + 1)) ≠ (◡𝑔‘𝑗))) |
| 63 | 62 | ralbidv 2497 |
. . . . . . . . 9
⊢ (𝑘 = (𝑛 + 1) → (∀𝑗 ∈ (0...𝑛)(◡𝑔‘𝑘) ≠ (◡𝑔‘𝑗) ↔ ∀𝑗 ∈ (0...𝑛)(◡𝑔‘(𝑛 + 1)) ≠ (◡𝑔‘𝑗))) |
| 64 | 63 | rspcev 2868 |
. . . . . . . 8
⊢ (((𝑛 + 1) ∈ ℕ0
∧ ∀𝑗 ∈
(0...𝑛)(◡𝑔‘(𝑛 + 1)) ≠ (◡𝑔‘𝑗)) → ∃𝑘 ∈ ℕ0 ∀𝑗 ∈ (0...𝑛)(◡𝑔‘𝑘) ≠ (◡𝑔‘𝑗)) |
| 65 | 31, 60, 64 | syl2anc 411 |
. . . . . . 7
⊢ ((𝑔:𝐴–1-1-onto→ℕ0 ∧ 𝑛 ∈ ℕ0) →
∃𝑘 ∈
ℕ0 ∀𝑗 ∈ (0...𝑛)(◡𝑔‘𝑘) ≠ (◡𝑔‘𝑗)) |
| 66 | 65 | ralrimiva 2570 |
. . . . . 6
⊢ (𝑔:𝐴–1-1-onto→ℕ0 → ∀𝑛 ∈ ℕ0
∃𝑘 ∈
ℕ0 ∀𝑗 ∈ (0...𝑛)(◡𝑔‘𝑘) ≠ (◡𝑔‘𝑗)) |
| 67 | | cnvexg 5207 |
. . . . . . . 8
⊢ (𝑔 ∈ V → ◡𝑔 ∈ V) |
| 68 | 67 | elv 2767 |
. . . . . . 7
⊢ ◡𝑔 ∈ V |
| 69 | | foeq1 5476 |
. . . . . . . 8
⊢ (𝑓 = ◡𝑔 → (𝑓:ℕ0–onto→𝐴 ↔ ◡𝑔:ℕ0–onto→𝐴)) |
| 70 | | fveq1 5557 |
. . . . . . . . . . 11
⊢ (𝑓 = ◡𝑔 → (𝑓‘𝑘) = (◡𝑔‘𝑘)) |
| 71 | | fveq1 5557 |
. . . . . . . . . . 11
⊢ (𝑓 = ◡𝑔 → (𝑓‘𝑗) = (◡𝑔‘𝑗)) |
| 72 | 70, 71 | neeq12d 2387 |
. . . . . . . . . 10
⊢ (𝑓 = ◡𝑔 → ((𝑓‘𝑘) ≠ (𝑓‘𝑗) ↔ (◡𝑔‘𝑘) ≠ (◡𝑔‘𝑗))) |
| 73 | 72 | rexralbidv 2523 |
. . . . . . . . 9
⊢ (𝑓 = ◡𝑔 → (∃𝑘 ∈ ℕ0 ∀𝑗 ∈ (0...𝑛)(𝑓‘𝑘) ≠ (𝑓‘𝑗) ↔ ∃𝑘 ∈ ℕ0 ∀𝑗 ∈ (0...𝑛)(◡𝑔‘𝑘) ≠ (◡𝑔‘𝑗))) |
| 74 | 73 | ralbidv 2497 |
. . . . . . . 8
⊢ (𝑓 = ◡𝑔 → (∀𝑛 ∈ ℕ0 ∃𝑘 ∈ ℕ0
∀𝑗 ∈ (0...𝑛)(𝑓‘𝑘) ≠ (𝑓‘𝑗) ↔ ∀𝑛 ∈ ℕ0 ∃𝑘 ∈ ℕ0
∀𝑗 ∈ (0...𝑛)(◡𝑔‘𝑘) ≠ (◡𝑔‘𝑗))) |
| 75 | 69, 74 | anbi12d 473 |
. . . . . . 7
⊢ (𝑓 = ◡𝑔 → ((𝑓:ℕ0–onto→𝐴 ∧ ∀𝑛 ∈ ℕ0 ∃𝑘 ∈ ℕ0
∀𝑗 ∈ (0...𝑛)(𝑓‘𝑘) ≠ (𝑓‘𝑗)) ↔ (◡𝑔:ℕ0–onto→𝐴 ∧ ∀𝑛 ∈ ℕ0 ∃𝑘 ∈ ℕ0
∀𝑗 ∈ (0...𝑛)(◡𝑔‘𝑘) ≠ (◡𝑔‘𝑗)))) |
| 76 | 68, 75 | spcev 2859 |
. . . . . 6
⊢ ((◡𝑔:ℕ0–onto→𝐴 ∧ ∀𝑛 ∈ ℕ0 ∃𝑘 ∈ ℕ0
∀𝑗 ∈ (0...𝑛)(◡𝑔‘𝑘) ≠ (◡𝑔‘𝑗)) → ∃𝑓(𝑓:ℕ0–onto→𝐴 ∧ ∀𝑛 ∈ ℕ0 ∃𝑘 ∈ ℕ0
∀𝑗 ∈ (0...𝑛)(𝑓‘𝑘) ≠ (𝑓‘𝑗))) |
| 77 | 29, 66, 76 | syl2anc 411 |
. . . . 5
⊢ (𝑔:𝐴–1-1-onto→ℕ0 → ∃𝑓(𝑓:ℕ0–onto→𝐴 ∧ ∀𝑛 ∈ ℕ0 ∃𝑘 ∈ ℕ0
∀𝑗 ∈ (0...𝑛)(𝑓‘𝑘) ≠ (𝑓‘𝑗))) |
| 78 | 26, 77 | jca 306 |
. . . 4
⊢ (𝑔:𝐴–1-1-onto→ℕ0 → (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 DECID 𝑥 = 𝑦 ∧ ∃𝑓(𝑓:ℕ0–onto→𝐴 ∧ ∀𝑛 ∈ ℕ0 ∃𝑘 ∈ ℕ0
∀𝑗 ∈ (0...𝑛)(𝑓‘𝑘) ≠ (𝑓‘𝑗)))) |
| 79 | 78 | adantl 277 |
. . 3
⊢ ((𝐴 ≈ ℕ0
∧ 𝑔:𝐴–1-1-onto→ℕ0) → (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 DECID 𝑥 = 𝑦 ∧ ∃𝑓(𝑓:ℕ0–onto→𝐴 ∧ ∀𝑛 ∈ ℕ0 ∃𝑘 ∈ ℕ0
∀𝑗 ∈ (0...𝑛)(𝑓‘𝑘) ≠ (𝑓‘𝑗)))) |
| 80 | 6, 79 | exlimddv 1913 |
. 2
⊢ (𝐴 ≈ ℕ0
→ (∀𝑥 ∈
𝐴 ∀𝑦 ∈ 𝐴 DECID 𝑥 = 𝑦 ∧ ∃𝑓(𝑓:ℕ0–onto→𝐴 ∧ ∀𝑛 ∈ ℕ0 ∃𝑘 ∈ ℕ0
∀𝑗 ∈ (0...𝑛)(𝑓‘𝑘) ≠ (𝑓‘𝑗)))) |
| 81 | 4, 80 | syl 14 |
1
⊢ (𝐴 ≈ ℕ →
(∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 DECID 𝑥 = 𝑦 ∧ ∃𝑓(𝑓:ℕ0–onto→𝐴 ∧ ∀𝑛 ∈ ℕ0 ∃𝑘 ∈ ℕ0
∀𝑗 ∈ (0...𝑛)(𝑓‘𝑘) ≠ (𝑓‘𝑗)))) |