Proof of Theorem 1tonninf
| Step | Hyp | Ref
| Expression |
| 1 | | fxnn0nninf.i |
. . . . 5
⊢ 𝐼 = ((𝐹 ∘ ◡𝐺) ∪ {〈+∞, (ω ×
{1o})〉}) |
| 2 | 1 | fveq1i 5559 |
. . . 4
⊢ (𝐼‘1) = (((𝐹 ∘ ◡𝐺) ∪ {〈+∞, (ω ×
{1o})〉})‘1) |
| 3 | | 1nn0 9265 |
. . . . . 6
⊢ 1 ∈
ℕ0 |
| 4 | | nn0xnn0 9316 |
. . . . . 6
⊢ (1 ∈
ℕ0 → 1 ∈
ℕ0*) |
| 5 | 3, 4 | ax-mp 5 |
. . . . 5
⊢ 1 ∈
ℕ0* |
| 6 | | nn0nepnf 9320 |
. . . . . . 7
⊢ (1 ∈
ℕ0 → 1 ≠ +∞) |
| 7 | 3, 6 | ax-mp 5 |
. . . . . 6
⊢ 1 ≠
+∞ |
| 8 | 7 | necomi 2452 |
. . . . 5
⊢ +∞
≠ 1 |
| 9 | | fvunsng 5756 |
. . . . 5
⊢ ((1
∈ ℕ0* ∧ +∞ ≠ 1) → (((𝐹 ∘ ◡𝐺) ∪ {〈+∞, (ω ×
{1o})〉})‘1) = ((𝐹 ∘ ◡𝐺)‘1)) |
| 10 | 5, 8, 9 | mp2an 426 |
. . . 4
⊢ (((𝐹 ∘ ◡𝐺) ∪ {〈+∞, (ω ×
{1o})〉})‘1) = ((𝐹 ∘ ◡𝐺)‘1) |
| 11 | | fxnn0nninf.g |
. . . . . . . 8
⊢ 𝐺 = frec((𝑥 ∈ ℤ ↦ (𝑥 + 1)), 0) |
| 12 | 11 | frechashgf1o 10520 |
. . . . . . 7
⊢ 𝐺:ω–1-1-onto→ℕ0 |
| 13 | | f1ocnv 5517 |
. . . . . . 7
⊢ (𝐺:ω–1-1-onto→ℕ0 → ◡𝐺:ℕ0–1-1-onto→ω) |
| 14 | 12, 13 | ax-mp 5 |
. . . . . 6
⊢ ◡𝐺:ℕ0–1-1-onto→ω |
| 15 | | f1of 5504 |
. . . . . 6
⊢ (◡𝐺:ℕ0–1-1-onto→ω → ◡𝐺:ℕ0⟶ω) |
| 16 | 14, 15 | ax-mp 5 |
. . . . 5
⊢ ◡𝐺:ℕ0⟶ω |
| 17 | | fvco3 5632 |
. . . . 5
⊢ ((◡𝐺:ℕ0⟶ω ∧ 1
∈ ℕ0) → ((𝐹 ∘ ◡𝐺)‘1) = (𝐹‘(◡𝐺‘1))) |
| 18 | 16, 3, 17 | mp2an 426 |
. . . 4
⊢ ((𝐹 ∘ ◡𝐺)‘1) = (𝐹‘(◡𝐺‘1)) |
| 19 | 2, 10, 18 | 3eqtri 2221 |
. . 3
⊢ (𝐼‘1) = (𝐹‘(◡𝐺‘1)) |
| 20 | | df-1o 6474 |
. . . . . . 7
⊢
1o = suc ∅ |
| 21 | 20 | fveq2i 5561 |
. . . . . 6
⊢ (𝐺‘1o) = (𝐺‘suc
∅) |
| 22 | | 0zd 9338 |
. . . . . . . . 9
⊢ (⊤
→ 0 ∈ ℤ) |
| 23 | | peano1 4630 |
. . . . . . . . . 10
⊢ ∅
∈ ω |
| 24 | 23 | a1i 9 |
. . . . . . . . 9
⊢ (⊤
→ ∅ ∈ ω) |
| 25 | 22, 11, 24 | frec2uzsucd 10493 |
. . . . . . . 8
⊢ (⊤
→ (𝐺‘suc
∅) = ((𝐺‘∅) + 1)) |
| 26 | 25 | mptru 1373 |
. . . . . . 7
⊢ (𝐺‘suc ∅) = ((𝐺‘∅) +
1) |
| 27 | 22, 11 | frec2uz0d 10491 |
. . . . . . . . 9
⊢ (⊤
→ (𝐺‘∅) =
0) |
| 28 | 27 | mptru 1373 |
. . . . . . . 8
⊢ (𝐺‘∅) =
0 |
| 29 | 28 | oveq1i 5932 |
. . . . . . 7
⊢ ((𝐺‘∅) + 1) = (0 +
1) |
| 30 | 26, 29 | eqtri 2217 |
. . . . . 6
⊢ (𝐺‘suc ∅) = (0 +
1) |
| 31 | | 0p1e1 9104 |
. . . . . 6
⊢ (0 + 1) =
1 |
| 32 | 21, 30, 31 | 3eqtri 2221 |
. . . . 5
⊢ (𝐺‘1o) =
1 |
| 33 | | 1onn 6578 |
. . . . . 6
⊢
1o ∈ ω |
| 34 | | f1ocnvfv 5826 |
. . . . . 6
⊢ ((𝐺:ω–1-1-onto→ℕ0 ∧ 1o ∈
ω) → ((𝐺‘1o) = 1 → (◡𝐺‘1) = 1o)) |
| 35 | 12, 33, 34 | mp2an 426 |
. . . . 5
⊢ ((𝐺‘1o) = 1 →
(◡𝐺‘1) = 1o) |
| 36 | 32, 35 | ax-mp 5 |
. . . 4
⊢ (◡𝐺‘1) = 1o |
| 37 | 36 | fveq2i 5561 |
. . 3
⊢ (𝐹‘(◡𝐺‘1)) = (𝐹‘1o) |
| 38 | | eleq2 2260 |
. . . . . . 7
⊢ (𝑛 = 1o → (𝑖 ∈ 𝑛 ↔ 𝑖 ∈ 1o)) |
| 39 | 38 | ifbid 3582 |
. . . . . 6
⊢ (𝑛 = 1o → if(𝑖 ∈ 𝑛, 1o, ∅) = if(𝑖 ∈ 1o,
1o, ∅)) |
| 40 | 39 | mpteq2dv 4124 |
. . . . 5
⊢ (𝑛 = 1o → (𝑖 ∈ ω ↦ if(𝑖 ∈ 𝑛, 1o, ∅)) = (𝑖 ∈ ω ↦ if(𝑖 ∈ 1o,
1o, ∅))) |
| 41 | | fxnn0nninf.f |
. . . . 5
⊢ 𝐹 = (𝑛 ∈ ω ↦ (𝑖 ∈ ω ↦ if(𝑖 ∈ 𝑛, 1o, ∅))) |
| 42 | | omex 4629 |
. . . . . 6
⊢ ω
∈ V |
| 43 | 42 | mptex 5788 |
. . . . 5
⊢ (𝑖 ∈ ω ↦ if(𝑖 ∈ 𝑛, 1o, ∅)) ∈
V |
| 44 | 40, 41, 43 | fvmpt3i 5641 |
. . . 4
⊢
(1o ∈ ω → (𝐹‘1o) = (𝑖 ∈ ω ↦ if(𝑖 ∈ 1o, 1o,
∅))) |
| 45 | 33, 44 | ax-mp 5 |
. . 3
⊢ (𝐹‘1o) = (𝑖 ∈ ω ↦ if(𝑖 ∈ 1o,
1o, ∅)) |
| 46 | 19, 37, 45 | 3eqtri 2221 |
. 2
⊢ (𝐼‘1) = (𝑖 ∈ ω ↦ if(𝑖 ∈ 1o, 1o,
∅)) |
| 47 | | el1o 6495 |
. . . 4
⊢ (𝑖 ∈ 1o ↔
𝑖 =
∅) |
| 48 | | ifbi 3581 |
. . . 4
⊢ ((𝑖 ∈ 1o ↔
𝑖 = ∅) →
if(𝑖 ∈ 1o,
1o, ∅) = if(𝑖 = ∅, 1o,
∅)) |
| 49 | 47, 48 | ax-mp 5 |
. . 3
⊢ if(𝑖 ∈ 1o,
1o, ∅) = if(𝑖 = ∅, 1o,
∅) |
| 50 | 49 | mpteq2i 4120 |
. 2
⊢ (𝑖 ∈ ω ↦ if(𝑖 ∈ 1o,
1o, ∅)) = (𝑖 ∈ ω ↦ if(𝑖 = ∅, 1o,
∅)) |
| 51 | | eqeq1 2203 |
. . . 4
⊢ (𝑖 = 𝑥 → (𝑖 = ∅ ↔ 𝑥 = ∅)) |
| 52 | 51 | ifbid 3582 |
. . 3
⊢ (𝑖 = 𝑥 → if(𝑖 = ∅, 1o, ∅) =
if(𝑥 = ∅,
1o, ∅)) |
| 53 | 52 | cbvmptv 4129 |
. 2
⊢ (𝑖 ∈ ω ↦ if(𝑖 = ∅, 1o,
∅)) = (𝑥 ∈
ω ↦ if(𝑥 =
∅, 1o, ∅)) |
| 54 | 46, 50, 53 | 3eqtri 2221 |
1
⊢ (𝐼‘1) = (𝑥 ∈ ω ↦ if(𝑥 = ∅, 1o,
∅)) |