Proof of Theorem fznatpl1
Step | Hyp | Ref
| Expression |
1 | | 1red 7914 |
. . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 1 ∈
ℝ) |
2 | | elfzelz 9960 |
. . . . . 6
⊢ (𝐼 ∈ (1...(𝑁 − 1)) → 𝐼 ∈ ℤ) |
3 | 2 | zred 9313 |
. . . . 5
⊢ (𝐼 ∈ (1...(𝑁 − 1)) → 𝐼 ∈ ℝ) |
4 | 3 | adantl 275 |
. . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 𝐼 ∈ ℝ) |
5 | | peano2re 8034 |
. . . 4
⊢ (𝐼 ∈ ℝ → (𝐼 + 1) ∈
ℝ) |
6 | 4, 5 | syl 14 |
. . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → (𝐼 + 1) ∈ ℝ) |
7 | | peano2re 8034 |
. . . . 5
⊢ (1 ∈
ℝ → (1 + 1) ∈ ℝ) |
8 | 1, 7 | syl 14 |
. . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → (1 + 1) ∈
ℝ) |
9 | 1 | ltp1d 8825 |
. . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 1 < (1 +
1)) |
10 | | elfzle1 9962 |
. . . . . 6
⊢ (𝐼 ∈ (1...(𝑁 − 1)) → 1 ≤ 𝐼) |
11 | 10 | adantl 275 |
. . . . 5
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 1 ≤ 𝐼) |
12 | | 1re 7898 |
. . . . . . 7
⊢ 1 ∈
ℝ |
13 | | leadd1 8328 |
. . . . . . 7
⊢ ((1
∈ ℝ ∧ 𝐼
∈ ℝ ∧ 1 ∈ ℝ) → (1 ≤ 𝐼 ↔ (1 + 1) ≤ (𝐼 + 1))) |
14 | 12, 12, 13 | mp3an13 1318 |
. . . . . 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 146 |
. . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → (1 + 1) ≤ (𝐼 + 1)) |
17 | 1, 8, 6, 9, 16 | ltletrd 8321 |
. . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 1 < (𝐼 + 1)) |
18 | 1, 6, 17 | ltled 8017 |
. 2
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 1 ≤ (𝐼 + 1)) |
19 | | elfzle2 9963 |
. . . 4
⊢ (𝐼 ∈ (1...(𝑁 − 1)) → 𝐼 ≤ (𝑁 − 1)) |
20 | 19 | adantl 275 |
. . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 𝐼 ≤ (𝑁 − 1)) |
21 | | nnz 9210 |
. . . . . 6
⊢ (𝑁 ∈ ℕ → 𝑁 ∈
ℤ) |
22 | 21 | adantr 274 |
. . . . 5
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 𝑁 ∈ ℤ) |
23 | 22 | zred 9313 |
. . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → 𝑁 ∈ ℝ) |
24 | | leaddsub 8336 |
. . . . 5
⊢ ((𝐼 ∈ ℝ ∧ 1 ∈
ℝ ∧ 𝑁 ∈
ℝ) → ((𝐼 + 1)
≤ 𝑁 ↔ 𝐼 ≤ (𝑁 − 1))) |
25 | 12, 24 | mp3an2 1315 |
. . . 4
⊢ ((𝐼 ∈ ℝ ∧ 𝑁 ∈ ℝ) → ((𝐼 + 1) ≤ 𝑁 ↔ 𝐼 ≤ (𝑁 − 1))) |
26 | 4, 23, 25 | syl2anc 409 |
. . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → ((𝐼 + 1) ≤ 𝑁 ↔ 𝐼 ≤ (𝑁 − 1))) |
27 | 20, 26 | mpbird 166 |
. 2
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → (𝐼 + 1) ≤ 𝑁) |
28 | 2 | peano2zd 9316 |
. . . 4
⊢ (𝐼 ∈ (1...(𝑁 − 1)) → (𝐼 + 1) ∈ ℤ) |
29 | 28 | adantl 275 |
. . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → (𝐼 + 1) ∈ ℤ) |
30 | | 1z 9217 |
. . . 4
⊢ 1 ∈
ℤ |
31 | | elfz 9950 |
. . . 4
⊢ (((𝐼 + 1) ∈ ℤ ∧ 1
∈ ℤ ∧ 𝑁
∈ ℤ) → ((𝐼
+ 1) ∈ (1...𝑁) ↔
(1 ≤ (𝐼 + 1) ∧
(𝐼 + 1) ≤ 𝑁))) |
32 | 30, 31 | mp3an2 1315 |
. . 3
⊢ (((𝐼 + 1) ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝐼 + 1) ∈ (1...𝑁) ↔ (1 ≤ (𝐼 + 1) ∧ (𝐼 + 1) ≤ 𝑁))) |
33 | 29, 22, 32 | syl2anc 409 |
. 2
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → ((𝐼 + 1) ∈ (1...𝑁) ↔ (1 ≤ (𝐼 + 1) ∧ (𝐼 + 1) ≤ 𝑁))) |
34 | 18, 27, 33 | mpbir2and 934 |
1
⊢ ((𝑁 ∈ ℕ ∧ 𝐼 ∈ (1...(𝑁 − 1))) → (𝐼 + 1) ∈ (1...𝑁)) |