Proof of Theorem fznatpl1
| Step | Hyp | Ref
| Expression |
| 1 | | 1red 8058 |
. . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 1 ∈
ℝ) |
| 2 | | elfzelz 10117 |
. . . . . 6
⊢ (𝐼 ∈ (1...(𝑁 − 1)) → 𝐼 ∈ ℤ) |
| 3 | 2 | zred 9465 |
. . . . 5
⊢ (𝐼 ∈ (1...(𝑁 − 1)) → 𝐼 ∈ ℝ) |
| 4 | 3 | adantl 277 |
. . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 𝐼 ∈ ℝ) |
| 5 | | peano2re 8179 |
. . . 4
⊢ (𝐼 ∈ ℝ → (𝐼 + 1) ∈
ℝ) |
| 6 | 4, 5 | syl 14 |
. . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → (𝐼 + 1) ∈ ℝ) |
| 7 | | peano2re 8179 |
. . . . 5
⊢ (1 ∈
ℝ → (1 + 1) ∈ ℝ) |
| 8 | 1, 7 | syl 14 |
. . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → (1 + 1) ∈
ℝ) |
| 9 | 1 | ltp1d 8974 |
. . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 1 < (1 +
1)) |
| 10 | | elfzle1 10119 |
. . . . . 6
⊢ (𝐼 ∈ (1...(𝑁 − 1)) → 1 ≤ 𝐼) |
| 11 | 10 | adantl 277 |
. . . . 5
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 1 ≤ 𝐼) |
| 12 | | 1re 8042 |
. . . . . . 7
⊢ 1 ∈
ℝ |
| 13 | | leadd1 8474 |
. . . . . . 7
⊢ ((1
∈ ℝ ∧ 𝐼
∈ ℝ ∧ 1 ∈ ℝ) → (1 ≤ 𝐼 ↔ (1 + 1) ≤ (𝐼 + 1))) |
| 14 | 12, 12, 13 | mp3an13 1339 |
. . . . . 6
⊢ (𝐼 ∈ ℝ → (1 ≤
𝐼 ↔ (1 + 1) ≤
(𝐼 + 1))) |
| 15 | 4, 14 | syl 14 |
. . . . 5
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → (1 ≤ 𝐼 ↔ (1 + 1) ≤ (𝐼 + 1))) |
| 16 | 11, 15 | mpbid 147 |
. . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → (1 + 1) ≤ (𝐼 + 1)) |
| 17 | 1, 8, 6, 9, 16 | ltletrd 8467 |
. . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 1 < (𝐼 + 1)) |
| 18 | 1, 6, 17 | ltled 8162 |
. 2
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 1 ≤ (𝐼 + 1)) |
| 19 | | elfzle2 10120 |
. . . 4
⊢ (𝐼 ∈ (1...(𝑁 − 1)) → 𝐼 ≤ (𝑁 − 1)) |
| 20 | 19 | adantl 277 |
. . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 𝐼 ≤ (𝑁 − 1)) |
| 21 | | nnz 9362 |
. . . . . 6
⊢ (𝑁 ∈ ℕ → 𝑁 ∈
ℤ) |
| 22 | 21 | adantr 276 |
. . . . 5
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 𝑁 ∈ ℤ) |
| 23 | 22 | zred 9465 |
. . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 𝑁 ∈ ℝ) |
| 24 | | leaddsub 8482 |
. . . . 5
⊢ ((𝐼 ∈ ℝ ∧ 1 ∈
ℝ ∧ 𝑁 ∈
ℝ) → ((𝐼 + 1)
≤ 𝑁 ↔ 𝐼 ≤ (𝑁 − 1))) |
| 25 | 12, 24 | mp3an2 1336 |
. . . 4
⊢ ((𝐼 ∈ ℝ ∧ 𝑁 ∈ ℝ) → ((𝐼 + 1) ≤ 𝑁 ↔ 𝐼 ≤ (𝑁 − 1))) |
| 26 | 4, 23, 25 | syl2anc 411 |
. . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → ((𝐼 + 1) ≤ 𝑁 ↔ 𝐼 ≤ (𝑁 − 1))) |
| 27 | 20, 26 | mpbird 167 |
. 2
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → (𝐼 + 1) ≤ 𝑁) |
| 28 | 2 | peano2zd 9468 |
. . . 4
⊢ (𝐼 ∈ (1...(𝑁 − 1)) → (𝐼 + 1) ∈ ℤ) |
| 29 | 28 | adantl 277 |
. . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → (𝐼 + 1) ∈ ℤ) |
| 30 | | 1z 9369 |
. . . 4
⊢ 1 ∈
ℤ |
| 31 | | elfz 10106 |
. . . 4
⊢ (((𝐼 + 1) ∈ ℤ ∧ 1
∈ ℤ ∧ 𝑁
∈ ℤ) → ((𝐼
+ 1) ∈ (1...𝑁) ↔
(1 ≤ (𝐼 + 1) ∧
(𝐼 + 1) ≤ 𝑁))) |
| 32 | 30, 31 | mp3an2 1336 |
. . 3
⊢ (((𝐼 + 1) ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝐼 + 1) ∈ (1...𝑁) ↔ (1 ≤ (𝐼 + 1) ∧ (𝐼 + 1) ≤ 𝑁))) |
| 33 | 29, 22, 32 | syl2anc 411 |
. 2
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → ((𝐼 + 1) ∈ (1...𝑁) ↔ (1 ≤ (𝐼 + 1) ∧ (𝐼 + 1) ≤ 𝑁))) |
| 34 | 18, 27, 33 | mpbir2and 946 |
1
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → (𝐼 + 1) ∈ (1...𝑁)) |