Proof of Theorem peano2z
| Step | Hyp | Ref
| Expression |
| 1 | | zre 9330 |
. . 3
⊢ (𝑁 ∈ ℤ → 𝑁 ∈
ℝ) |
| 2 | | 1red 8041 |
. . 3
⊢ (𝑁 ∈ ℤ → 1 ∈
ℝ) |
| 3 | 1, 2 | readdcld 8056 |
. 2
⊢ (𝑁 ∈ ℤ → (𝑁 + 1) ∈
ℝ) |
| 4 | | elznn0nn 9340 |
. . . . 5
⊢ (𝑁 ∈ ℤ ↔ (𝑁 ∈ ℕ0 ∨
(𝑁 ∈ ℝ ∧
-𝑁 ∈
ℕ))) |
| 5 | 4 | biimpi 120 |
. . . 4
⊢ (𝑁 ∈ ℤ → (𝑁 ∈ ℕ0 ∨
(𝑁 ∈ ℝ ∧
-𝑁 ∈
ℕ))) |
| 6 | 1 | biantrurd 305 |
. . . . 5
⊢ (𝑁 ∈ ℤ → (-𝑁 ∈ ℕ ↔ (𝑁 ∈ ℝ ∧ -𝑁 ∈
ℕ))) |
| 7 | 6 | orbi2d 791 |
. . . 4
⊢ (𝑁 ∈ ℤ → ((𝑁 ∈ ℕ0 ∨
-𝑁 ∈ ℕ) ↔
(𝑁 ∈
ℕ0 ∨ (𝑁
∈ ℝ ∧ -𝑁
∈ ℕ)))) |
| 8 | 5, 7 | mpbird 167 |
. . 3
⊢ (𝑁 ∈ ℤ → (𝑁 ∈ ℕ0 ∨
-𝑁 ∈
ℕ)) |
| 9 | | peano2nn0 9289 |
. . . . 5
⊢ (𝑁 ∈ ℕ0
→ (𝑁 + 1) ∈
ℕ0) |
| 10 | 9 | a1i 9 |
. . . 4
⊢ (𝑁 ∈ ℤ → (𝑁 ∈ ℕ0
→ (𝑁 + 1) ∈
ℕ0)) |
| 11 | 1 | adantr 276 |
. . . . . . . . 9
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → 𝑁 ∈
ℝ) |
| 12 | | 1red 8041 |
. . . . . . . . 9
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → 1 ∈
ℝ) |
| 13 | 11, 12 | readdcld 8056 |
. . . . . . . 8
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → (𝑁 + 1) ∈
ℝ) |
| 14 | 13 | renegcld 8406 |
. . . . . . 7
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → -(𝑁 + 1) ∈
ℝ) |
| 15 | 14 | recnd 8055 |
. . . . . 6
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → -(𝑁 + 1) ∈
ℂ) |
| 16 | 11 | recnd 8055 |
. . . . . . . . . . . 12
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → 𝑁 ∈
ℂ) |
| 17 | | 1cnd 8042 |
. . . . . . . . . . . 12
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → 1 ∈
ℂ) |
| 18 | 16, 17 | negdid 8350 |
. . . . . . . . . . 11
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → -(𝑁 + 1) = (-𝑁 + -1)) |
| 19 | 18 | oveq1d 5937 |
. . . . . . . . . 10
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → (-(𝑁 + 1) + 1) = ((-𝑁 + -1) + 1)) |
| 20 | 16 | negcld 8324 |
. . . . . . . . . . 11
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → -𝑁 ∈
ℂ) |
| 21 | | neg1cn 9095 |
. . . . . . . . . . . 12
⊢ -1 ∈
ℂ |
| 22 | 21 | a1i 9 |
. . . . . . . . . . 11
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → -1
∈ ℂ) |
| 23 | 20, 22, 17 | addassd 8049 |
. . . . . . . . . 10
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → ((-𝑁 + -1) + 1) = (-𝑁 + (-1 + 1))) |
| 24 | 19, 23 | eqtrd 2229 |
. . . . . . . . 9
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → (-(𝑁 + 1) + 1) = (-𝑁 + (-1 + 1))) |
| 25 | | ax-1cn 7972 |
. . . . . . . . . . 11
⊢ 1 ∈
ℂ |
| 26 | | 1pneg1e0 9101 |
. . . . . . . . . . 11
⊢ (1 + -1)
= 0 |
| 27 | 25, 21, 26 | addcomli 8171 |
. . . . . . . . . 10
⊢ (-1 + 1)
= 0 |
| 28 | 27 | oveq2i 5933 |
. . . . . . . . 9
⊢ (-𝑁 + (-1 + 1)) = (-𝑁 + 0) |
| 29 | 24, 28 | eqtrdi 2245 |
. . . . . . . 8
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → (-(𝑁 + 1) + 1) = (-𝑁 + 0)) |
| 30 | 20 | addridd 8175 |
. . . . . . . 8
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → (-𝑁 + 0) = -𝑁) |
| 31 | 29, 30 | eqtrd 2229 |
. . . . . . 7
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → (-(𝑁 + 1) + 1) = -𝑁) |
| 32 | | simpr 110 |
. . . . . . 7
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → -𝑁 ∈
ℕ) |
| 33 | 31, 32 | eqeltrd 2273 |
. . . . . 6
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → (-(𝑁 + 1) + 1) ∈
ℕ) |
| 34 | | elnn0nn 9291 |
. . . . . 6
⊢ (-(𝑁 + 1) ∈ ℕ0
↔ (-(𝑁 + 1) ∈
ℂ ∧ (-(𝑁 + 1) +
1) ∈ ℕ)) |
| 35 | 15, 33, 34 | sylanbrc 417 |
. . . . 5
⊢ ((𝑁 ∈ ℤ ∧ -𝑁 ∈ ℕ) → -(𝑁 + 1) ∈
ℕ0) |
| 36 | 35 | ex 115 |
. . . 4
⊢ (𝑁 ∈ ℤ → (-𝑁 ∈ ℕ → -(𝑁 + 1) ∈
ℕ0)) |
| 37 | 10, 36 | orim12d 787 |
. . 3
⊢ (𝑁 ∈ ℤ → ((𝑁 ∈ ℕ0 ∨
-𝑁 ∈ ℕ) →
((𝑁 + 1) ∈
ℕ0 ∨ -(𝑁 + 1) ∈
ℕ0))) |
| 38 | 8, 37 | mpd 13 |
. 2
⊢ (𝑁 ∈ ℤ → ((𝑁 + 1) ∈ ℕ0
∨ -(𝑁 + 1) ∈
ℕ0)) |
| 39 | | elznn0 9341 |
. 2
⊢ ((𝑁 + 1) ∈ ℤ ↔
((𝑁 + 1) ∈ ℝ
∧ ((𝑁 + 1) ∈
ℕ0 ∨ -(𝑁 + 1) ∈
ℕ0))) |
| 40 | 3, 38, 39 | sylanbrc 417 |
1
⊢ (𝑁 ∈ ℤ → (𝑁 + 1) ∈
ℤ) |