Proof of Theorem fsum0diaglem
| Step | Hyp | Ref
| Expression |
| 1 | | elfzle1 10119 |
. . . . . . 7
⊢ (𝑗 ∈ (0...𝑁) → 0 ≤ 𝑗) |
| 2 | 1 | adantr 276 |
. . . . . 6
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → 0 ≤ 𝑗) |
| 3 | | elfz3nn0 10207 |
. . . . . . . . . 10
⊢ (𝑗 ∈ (0...𝑁) → 𝑁 ∈
ℕ0) |
| 4 | 3 | adantr 276 |
. . . . . . . . 9
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → 𝑁 ∈
ℕ0) |
| 5 | 4 | nn0zd 9463 |
. . . . . . . 8
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → 𝑁 ∈ ℤ) |
| 6 | 5 | zred 9465 |
. . . . . . 7
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → 𝑁 ∈ ℝ) |
| 7 | | elfzelz 10117 |
. . . . . . . . 9
⊢ (𝑗 ∈ (0...𝑁) → 𝑗 ∈ ℤ) |
| 8 | 7 | adantr 276 |
. . . . . . . 8
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → 𝑗 ∈ ℤ) |
| 9 | 8 | zred 9465 |
. . . . . . 7
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → 𝑗 ∈ ℝ) |
| 10 | 6, 9 | subge02d 8581 |
. . . . . 6
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → (0 ≤ 𝑗 ↔ (𝑁 − 𝑗) ≤ 𝑁)) |
| 11 | 2, 10 | mpbid 147 |
. . . . 5
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → (𝑁 − 𝑗) ≤ 𝑁) |
| 12 | 5, 8 | zsubcld 9470 |
. . . . . 6
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → (𝑁 − 𝑗) ∈ ℤ) |
| 13 | | eluz 9631 |
. . . . . 6
⊢ (((𝑁 − 𝑗) ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑁 ∈ (ℤ≥‘(𝑁 − 𝑗)) ↔ (𝑁 − 𝑗) ≤ 𝑁)) |
| 14 | 12, 5, 13 | syl2anc 411 |
. . . . 5
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → (𝑁 ∈ (ℤ≥‘(𝑁 − 𝑗)) ↔ (𝑁 − 𝑗) ≤ 𝑁)) |
| 15 | 11, 14 | mpbird 167 |
. . . 4
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → 𝑁 ∈ (ℤ≥‘(𝑁 − 𝑗))) |
| 16 | | fzss2 10156 |
. . . 4
⊢ (𝑁 ∈
(ℤ≥‘(𝑁 − 𝑗)) → (0...(𝑁 − 𝑗)) ⊆ (0...𝑁)) |
| 17 | 15, 16 | syl 14 |
. . 3
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → (0...(𝑁 − 𝑗)) ⊆ (0...𝑁)) |
| 18 | | simpr 110 |
. . 3
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → 𝑘 ∈ (0...(𝑁 − 𝑗))) |
| 19 | 17, 18 | sseldd 3185 |
. 2
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → 𝑘 ∈ (0...𝑁)) |
| 20 | | elfzelz 10117 |
. . . . . 6
⊢ (𝑘 ∈ (0...(𝑁 − 𝑗)) → 𝑘 ∈ ℤ) |
| 21 | 20 | adantl 277 |
. . . . 5
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → 𝑘 ∈ ℤ) |
| 22 | 21 | zred 9465 |
. . . 4
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → 𝑘 ∈ ℝ) |
| 23 | | elfzle2 10120 |
. . . . 5
⊢ (𝑘 ∈ (0...(𝑁 − 𝑗)) → 𝑘 ≤ (𝑁 − 𝑗)) |
| 24 | 23 | adantl 277 |
. . . 4
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → 𝑘 ≤ (𝑁 − 𝑗)) |
| 25 | 22, 6, 9, 24 | lesubd 8593 |
. . 3
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → 𝑗 ≤ (𝑁 − 𝑘)) |
| 26 | | elfzuz 10113 |
. . . . 5
⊢ (𝑗 ∈ (0...𝑁) → 𝑗 ∈
(ℤ≥‘0)) |
| 27 | 26 | adantr 276 |
. . . 4
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → 𝑗 ∈
(ℤ≥‘0)) |
| 28 | 5, 21 | zsubcld 9470 |
. . . 4
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → (𝑁 − 𝑘) ∈ ℤ) |
| 29 | | elfz5 10109 |
. . . 4
⊢ ((𝑗 ∈
(ℤ≥‘0) ∧ (𝑁 − 𝑘) ∈ ℤ) → (𝑗 ∈ (0...(𝑁 − 𝑘)) ↔ 𝑗 ≤ (𝑁 − 𝑘))) |
| 30 | 27, 28, 29 | syl2anc 411 |
. . 3
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → (𝑗 ∈ (0...(𝑁 − 𝑘)) ↔ 𝑗 ≤ (𝑁 − 𝑘))) |
| 31 | 25, 30 | mpbird 167 |
. 2
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → 𝑗 ∈ (0...(𝑁 − 𝑘))) |
| 32 | 19, 31 | jca 306 |
1
⊢ ((𝑗 ∈ (0...𝑁) ∧ 𝑘 ∈ (0...(𝑁 − 𝑗))) → (𝑘 ∈ (0...𝑁) ∧ 𝑗 ∈ (0...(𝑁 − 𝑘)))) |