| Step | Hyp | Ref
| Expression |
| 1 | | 2sq 27560 |
. 2
⊢ ((𝑃 ∈ ℙ ∧ (𝑃 mod 4) = 1) → ∃𝑎 ∈ ℤ ∃𝑏 ∈ ℤ 𝑃 = ((𝑎↑2) + (𝑏↑2))) |
| 2 | | oveq1 7418 |
. . . . . . 7
⊢ (𝑥 = if(0 ≤ 𝑎, 𝑎, -𝑎) → (𝑥↑2) = (if(0 ≤ 𝑎, 𝑎, -𝑎)↑2)) |
| 3 | 2 | oveq1d 7426 |
. . . . . 6
⊢ (𝑥 = if(0 ≤ 𝑎, 𝑎, -𝑎) → ((𝑥↑2) + (𝑦↑2)) = ((if(0 ≤ 𝑎, 𝑎, -𝑎)↑2) + (𝑦↑2))) |
| 4 | 3 | eqeq2d 2780 |
. . . . 5
⊢ (𝑥 = if(0 ≤ 𝑎, 𝑎, -𝑎) → (𝑃 = ((𝑥↑2) + (𝑦↑2)) ↔ 𝑃 = ((if(0 ≤ 𝑎, 𝑎, -𝑎)↑2) + (𝑦↑2)))) |
| 5 | | oveq1 7418 |
. . . . . . 7
⊢ (𝑦 = if(0 ≤ 𝑏, 𝑏, -𝑏) → (𝑦↑2) = (if(0 ≤ 𝑏, 𝑏, -𝑏)↑2)) |
| 6 | 5 | oveq2d 7427 |
. . . . . 6
⊢ (𝑦 = if(0 ≤ 𝑏, 𝑏, -𝑏) → ((if(0 ≤ 𝑎, 𝑎, -𝑎)↑2) + (𝑦↑2)) = ((if(0 ≤ 𝑎, 𝑎, -𝑎)↑2) + (if(0 ≤ 𝑏, 𝑏, -𝑏)↑2))) |
| 7 | 6 | eqeq2d 2780 |
. . . . 5
⊢ (𝑦 = if(0 ≤ 𝑏, 𝑏, -𝑏) → (𝑃 = ((if(0 ≤ 𝑎, 𝑎, -𝑎)↑2) + (𝑦↑2)) ↔ 𝑃 = ((if(0 ≤ 𝑎, 𝑎, -𝑎)↑2) + (if(0 ≤ 𝑏, 𝑏, -𝑏)↑2)))) |
| 8 | | elnn0z 12604 |
. . . . . . . . 9
⊢ (𝑎 ∈ ℕ0
↔ (𝑎 ∈ ℤ
∧ 0 ≤ 𝑎)) |
| 9 | 8 | biimpri 231 |
. . . . . . . 8
⊢ ((𝑎 ∈ ℤ ∧ 0 ≤
𝑎) → 𝑎 ∈
ℕ0) |
| 10 | | elznn0 12606 |
. . . . . . . . . 10
⊢ (𝑎 ∈ ℤ ↔ (𝑎 ∈ ℝ ∧ (𝑎 ∈ ℕ0 ∨
-𝑎 ∈
ℕ0))) |
| 11 | | nn0ge0 12529 |
. . . . . . . . . . . . . 14
⊢ (𝑎 ∈ ℕ0
→ 0 ≤ 𝑎) |
| 12 | 11 | pm2.24d 152 |
. . . . . . . . . . . . 13
⊢ (𝑎 ∈ ℕ0
→ (¬ 0 ≤ 𝑎
→ -𝑎 ∈
ℕ0)) |
| 13 | 12 | a1i 11 |
. . . . . . . . . . . 12
⊢ (𝑎 ∈ ℝ → (𝑎 ∈ ℕ0
→ (¬ 0 ≤ 𝑎
→ -𝑎 ∈
ℕ0))) |
| 14 | | ax1w 13 |
. . . . . . . . . . . 12
⊢ (𝑎 ∈ ℝ → (-𝑎 ∈ ℕ0
→ (¬ 0 ≤ 𝑎
→ -𝑎 ∈
ℕ0))) |
| 15 | 13, 14 | jaod 872 |
. . . . . . . . . . 11
⊢ (𝑎 ∈ ℝ → ((𝑎 ∈ ℕ0 ∨
-𝑎 ∈
ℕ0) → (¬ 0 ≤ 𝑎 → -𝑎 ∈
ℕ0))) |
| 16 | 15 | imp 411 |
. . . . . . . . . 10
⊢ ((𝑎 ∈ ℝ ∧ (𝑎 ∈ ℕ0 ∨
-𝑎 ∈
ℕ0)) → (¬ 0 ≤ 𝑎 → -𝑎 ∈
ℕ0)) |
| 17 | 10, 16 | sylbi 220 |
. . . . . . . . 9
⊢ (𝑎 ∈ ℤ → (¬ 0
≤ 𝑎 → -𝑎 ∈
ℕ0)) |
| 18 | 17 | imp 411 |
. . . . . . . 8
⊢ ((𝑎 ∈ ℤ ∧ ¬ 0
≤ 𝑎) → -𝑎 ∈
ℕ0) |
| 19 | 9, 18 | ifclda 4528 |
. . . . . . 7
⊢ (𝑎 ∈ ℤ → if(0 ≤
𝑎, 𝑎, -𝑎) ∈
ℕ0) |
| 20 | 19 | adantr 485 |
. . . . . 6
⊢ ((𝑎 ∈ ℤ ∧ 𝑏 ∈ ℤ) → if(0
≤ 𝑎, 𝑎, -𝑎) ∈
ℕ0) |
| 21 | 20 | adantr 485 |
. . . . 5
⊢ (((𝑎 ∈ ℤ ∧ 𝑏 ∈ ℤ) ∧ 𝑃 = ((𝑎↑2) + (𝑏↑2))) → if(0 ≤ 𝑎, 𝑎, -𝑎) ∈
ℕ0) |
| 22 | | elnn0z 12604 |
. . . . . . . 8
⊢ (𝑏 ∈ ℕ0
↔ (𝑏 ∈ ℤ
∧ 0 ≤ 𝑏)) |
| 23 | 22 | biimpri 231 |
. . . . . . 7
⊢ ((𝑏 ∈ ℤ ∧ 0 ≤
𝑏) → 𝑏 ∈
ℕ0) |
| 24 | | elznn0 12606 |
. . . . . . . . 9
⊢ (𝑏 ∈ ℤ ↔ (𝑏 ∈ ℝ ∧ (𝑏 ∈ ℕ0 ∨
-𝑏 ∈
ℕ0))) |
| 25 | | nn0ge0 12529 |
. . . . . . . . . . . . 13
⊢ (𝑏 ∈ ℕ0
→ 0 ≤ 𝑏) |
| 26 | 25 | pm2.24d 152 |
. . . . . . . . . . . 12
⊢ (𝑏 ∈ ℕ0
→ (¬ 0 ≤ 𝑏
→ -𝑏 ∈
ℕ0)) |
| 27 | 26 | a1i 11 |
. . . . . . . . . . 11
⊢ (𝑏 ∈ ℝ → (𝑏 ∈ ℕ0
→ (¬ 0 ≤ 𝑏
→ -𝑏 ∈
ℕ0))) |
| 28 | | ax1w 13 |
. . . . . . . . . . 11
⊢ (𝑏 ∈ ℝ → (-𝑏 ∈ ℕ0
→ (¬ 0 ≤ 𝑏
→ -𝑏 ∈
ℕ0))) |
| 29 | 27, 28 | jaod 872 |
. . . . . . . . . 10
⊢ (𝑏 ∈ ℝ → ((𝑏 ∈ ℕ0 ∨
-𝑏 ∈
ℕ0) → (¬ 0 ≤ 𝑏 → -𝑏 ∈
ℕ0))) |
| 30 | 29 | imp 411 |
. . . . . . . . 9
⊢ ((𝑏 ∈ ℝ ∧ (𝑏 ∈ ℕ0 ∨
-𝑏 ∈
ℕ0)) → (¬ 0 ≤ 𝑏 → -𝑏 ∈
ℕ0)) |
| 31 | 24, 30 | sylbi 220 |
. . . . . . . 8
⊢ (𝑏 ∈ ℤ → (¬ 0
≤ 𝑏 → -𝑏 ∈
ℕ0)) |
| 32 | 31 | imp 411 |
. . . . . . 7
⊢ ((𝑏 ∈ ℤ ∧ ¬ 0
≤ 𝑏) → -𝑏 ∈
ℕ0) |
| 33 | 23, 32 | ifclda 4528 |
. . . . . 6
⊢ (𝑏 ∈ ℤ → if(0 ≤
𝑏, 𝑏, -𝑏) ∈
ℕ0) |
| 34 | 33 | ad2antlr 739 |
. . . . 5
⊢ (((𝑎 ∈ ℤ ∧ 𝑏 ∈ ℤ) ∧ 𝑃 = ((𝑎↑2) + (𝑏↑2))) → if(0 ≤ 𝑏, 𝑏, -𝑏) ∈
ℕ0) |
| 35 | | elznn0nn 12605 |
. . . . . . . . . 10
⊢ (𝑎 ∈ ℤ ↔ (𝑎 ∈ ℕ0 ∨
(𝑎 ∈ ℝ ∧
-𝑎 ∈
ℕ))) |
| 36 | 11 | iftrued 4500 |
. . . . . . . . . . . . 13
⊢ (𝑎 ∈ ℕ0
→ if(0 ≤ 𝑎, 𝑎, -𝑎) = 𝑎) |
| 37 | 36 | eqcomd 2775 |
. . . . . . . . . . . 12
⊢ (𝑎 ∈ ℕ0
→ 𝑎 = if(0 ≤ 𝑎, 𝑎, -𝑎)) |
| 38 | 37 | oveq1d 7426 |
. . . . . . . . . . 11
⊢ (𝑎 ∈ ℕ0
→ (𝑎↑2) = (if(0
≤ 𝑎, 𝑎, -𝑎)↑2)) |
| 39 | | elnnz 12601 |
. . . . . . . . . . . . . . . 16
⊢ (-𝑎 ∈ ℕ ↔ (-𝑎 ∈ ℤ ∧ 0 <
-𝑎)) |
| 40 | | lt0neg1 11720 |
. . . . . . . . . . . . . . . . . 18
⊢ (𝑎 ∈ ℝ → (𝑎 < 0 ↔ 0 < -𝑎)) |
| 41 | | id 23 |
. . . . . . . . . . . . . . . . . . . 20
⊢ (𝑎 ∈ ℝ → 𝑎 ∈
ℝ) |
| 42 | | 0red 11211 |
. . . . . . . . . . . . . . . . . . . 20
⊢ (𝑎 ∈ ℝ → 0 ∈
ℝ) |
| 43 | 41, 42 | ltnled 11357 |
. . . . . . . . . . . . . . . . . . 19
⊢ (𝑎 ∈ ℝ → (𝑎 < 0 ↔ ¬ 0 ≤
𝑎)) |
| 44 | 43 | biimpd 232 |
. . . . . . . . . . . . . . . . . 18
⊢ (𝑎 ∈ ℝ → (𝑎 < 0 → ¬ 0 ≤
𝑎)) |
| 45 | 40, 44 | sylbird 263 |
. . . . . . . . . . . . . . . . 17
⊢ (𝑎 ∈ ℝ → (0 <
-𝑎 → ¬ 0 ≤
𝑎)) |
| 46 | 45 | com12 33 |
. . . . . . . . . . . . . . . 16
⊢ (0 <
-𝑎 → (𝑎 ∈ ℝ → ¬ 0
≤ 𝑎)) |
| 47 | 39, 46 | simplbiim 513 |
. . . . . . . . . . . . . . 15
⊢ (-𝑎 ∈ ℕ → (𝑎 ∈ ℝ → ¬ 0
≤ 𝑎)) |
| 48 | 47 | impcom 412 |
. . . . . . . . . . . . . 14
⊢ ((𝑎 ∈ ℝ ∧ -𝑎 ∈ ℕ) → ¬ 0
≤ 𝑎) |
| 49 | 48 | iffalsed 4503 |
. . . . . . . . . . . . 13
⊢ ((𝑎 ∈ ℝ ∧ -𝑎 ∈ ℕ) → if(0
≤ 𝑎, 𝑎, -𝑎) = -𝑎) |
| 50 | 49 | oveq1d 7426 |
. . . . . . . . . . . 12
⊢ ((𝑎 ∈ ℝ ∧ -𝑎 ∈ ℕ) → (if(0
≤ 𝑎, 𝑎, -𝑎)↑2) = (-𝑎↑2)) |
| 51 | | recn 11190 |
. . . . . . . . . . . . . 14
⊢ (𝑎 ∈ ℝ → 𝑎 ∈
ℂ) |
| 52 | 51 | sqnegd 14152 |
. . . . . . . . . . . . 13
⊢ (𝑎 ∈ ℝ → (-𝑎↑2) = (𝑎↑2)) |
| 53 | 52 | adantr 485 |
. . . . . . . . . . . 12
⊢ ((𝑎 ∈ ℝ ∧ -𝑎 ∈ ℕ) → (-𝑎↑2) = (𝑎↑2)) |
| 54 | 50, 53 | eqtr2d 2805 |
. . . . . . . . . . 11
⊢ ((𝑎 ∈ ℝ ∧ -𝑎 ∈ ℕ) → (𝑎↑2) = (if(0 ≤ 𝑎, 𝑎, -𝑎)↑2)) |
| 55 | 38, 54 | jaoi 870 |
. . . . . . . . . 10
⊢ ((𝑎 ∈ ℕ0 ∨
(𝑎 ∈ ℝ ∧
-𝑎 ∈ ℕ)) →
(𝑎↑2) = (if(0 ≤
𝑎, 𝑎, -𝑎)↑2)) |
| 56 | 35, 55 | sylbi 220 |
. . . . . . . . 9
⊢ (𝑎 ∈ ℤ → (𝑎↑2) = (if(0 ≤ 𝑎, 𝑎, -𝑎)↑2)) |
| 57 | | elznn0nn 12605 |
. . . . . . . . . 10
⊢ (𝑏 ∈ ℤ ↔ (𝑏 ∈ ℕ0 ∨
(𝑏 ∈ ℝ ∧
-𝑏 ∈
ℕ))) |
| 58 | 25 | iftrued 4500 |
. . . . . . . . . . . . 13
⊢ (𝑏 ∈ ℕ0
→ if(0 ≤ 𝑏, 𝑏, -𝑏) = 𝑏) |
| 59 | 58 | eqcomd 2775 |
. . . . . . . . . . . 12
⊢ (𝑏 ∈ ℕ0
→ 𝑏 = if(0 ≤ 𝑏, 𝑏, -𝑏)) |
| 60 | 59 | oveq1d 7426 |
. . . . . . . . . . 11
⊢ (𝑏 ∈ ℕ0
→ (𝑏↑2) = (if(0
≤ 𝑏, 𝑏, -𝑏)↑2)) |
| 61 | | elnnz 12601 |
. . . . . . . . . . . . . . . 16
⊢ (-𝑏 ∈ ℕ ↔ (-𝑏 ∈ ℤ ∧ 0 <
-𝑏)) |
| 62 | | lt0neg1 11720 |
. . . . . . . . . . . . . . . . . 18
⊢ (𝑏 ∈ ℝ → (𝑏 < 0 ↔ 0 < -𝑏)) |
| 63 | | id 23 |
. . . . . . . . . . . . . . . . . . . 20
⊢ (𝑏 ∈ ℝ → 𝑏 ∈
ℝ) |
| 64 | | 0red 11211 |
. . . . . . . . . . . . . . . . . . . 20
⊢ (𝑏 ∈ ℝ → 0 ∈
ℝ) |
| 65 | 63, 64 | ltnled 11357 |
. . . . . . . . . . . . . . . . . . 19
⊢ (𝑏 ∈ ℝ → (𝑏 < 0 ↔ ¬ 0 ≤
𝑏)) |
| 66 | 65 | biimpd 232 |
. . . . . . . . . . . . . . . . . 18
⊢ (𝑏 ∈ ℝ → (𝑏 < 0 → ¬ 0 ≤
𝑏)) |
| 67 | 62, 66 | sylbird 263 |
. . . . . . . . . . . . . . . . 17
⊢ (𝑏 ∈ ℝ → (0 <
-𝑏 → ¬ 0 ≤
𝑏)) |
| 68 | 67 | com12 33 |
. . . . . . . . . . . . . . . 16
⊢ (0 <
-𝑏 → (𝑏 ∈ ℝ → ¬ 0
≤ 𝑏)) |
| 69 | 61, 68 | simplbiim 513 |
. . . . . . . . . . . . . . 15
⊢ (-𝑏 ∈ ℕ → (𝑏 ∈ ℝ → ¬ 0
≤ 𝑏)) |
| 70 | 69 | impcom 412 |
. . . . . . . . . . . . . 14
⊢ ((𝑏 ∈ ℝ ∧ -𝑏 ∈ ℕ) → ¬ 0
≤ 𝑏) |
| 71 | 70 | iffalsed 4503 |
. . . . . . . . . . . . 13
⊢ ((𝑏 ∈ ℝ ∧ -𝑏 ∈ ℕ) → if(0
≤ 𝑏, 𝑏, -𝑏) = -𝑏) |
| 72 | 71 | oveq1d 7426 |
. . . . . . . . . . . 12
⊢ ((𝑏 ∈ ℝ ∧ -𝑏 ∈ ℕ) → (if(0
≤ 𝑏, 𝑏, -𝑏)↑2) = (-𝑏↑2)) |
| 73 | | recn 11190 |
. . . . . . . . . . . . . 14
⊢ (𝑏 ∈ ℝ → 𝑏 ∈
ℂ) |
| 74 | 73 | sqnegd 14152 |
. . . . . . . . . . . . 13
⊢ (𝑏 ∈ ℝ → (-𝑏↑2) = (𝑏↑2)) |
| 75 | 74 | adantr 485 |
. . . . . . . . . . . 12
⊢ ((𝑏 ∈ ℝ ∧ -𝑏 ∈ ℕ) → (-𝑏↑2) = (𝑏↑2)) |
| 76 | 72, 75 | eqtr2d 2805 |
. . . . . . . . . . 11
⊢ ((𝑏 ∈ ℝ ∧ -𝑏 ∈ ℕ) → (𝑏↑2) = (if(0 ≤ 𝑏, 𝑏, -𝑏)↑2)) |
| 77 | 60, 76 | jaoi 870 |
. . . . . . . . . 10
⊢ ((𝑏 ∈ ℕ0 ∨
(𝑏 ∈ ℝ ∧
-𝑏 ∈ ℕ)) →
(𝑏↑2) = (if(0 ≤
𝑏, 𝑏, -𝑏)↑2)) |
| 78 | 57, 77 | sylbi 220 |
. . . . . . . . 9
⊢ (𝑏 ∈ ℤ → (𝑏↑2) = (if(0 ≤ 𝑏, 𝑏, -𝑏)↑2)) |
| 79 | 56, 78 | oveqan12d 7430 |
. . . . . . . 8
⊢ ((𝑎 ∈ ℤ ∧ 𝑏 ∈ ℤ) → ((𝑎↑2) + (𝑏↑2)) = ((if(0 ≤ 𝑎, 𝑎, -𝑎)↑2) + (if(0 ≤ 𝑏, 𝑏, -𝑏)↑2))) |
| 80 | 79 | eqeq2d 2780 |
. . . . . . 7
⊢ ((𝑎 ∈ ℤ ∧ 𝑏 ∈ ℤ) → (𝑃 = ((𝑎↑2) + (𝑏↑2)) ↔ 𝑃 = ((if(0 ≤ 𝑎, 𝑎, -𝑎)↑2) + (if(0 ≤ 𝑏, 𝑏, -𝑏)↑2)))) |
| 81 | 80 | biimpd 232 |
. . . . . 6
⊢ ((𝑎 ∈ ℤ ∧ 𝑏 ∈ ℤ) → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → 𝑃 = ((if(0 ≤ 𝑎, 𝑎, -𝑎)↑2) + (if(0 ≤ 𝑏, 𝑏, -𝑏)↑2)))) |
| 82 | 81 | imp 411 |
. . . . 5
⊢ (((𝑎 ∈ ℤ ∧ 𝑏 ∈ ℤ) ∧ 𝑃 = ((𝑎↑2) + (𝑏↑2))) → 𝑃 = ((if(0 ≤ 𝑎, 𝑎, -𝑎)↑2) + (if(0 ≤ 𝑏, 𝑏, -𝑏)↑2))) |
| 83 | 4, 7, 21, 34, 82 | 2rspcedvdw 3604 |
. . . 4
⊢ (((𝑎 ∈ ℤ ∧ 𝑏 ∈ ℤ) ∧ 𝑃 = ((𝑎↑2) + (𝑏↑2))) → ∃𝑥 ∈ ℕ0 ∃𝑦 ∈ ℕ0
𝑃 = ((𝑥↑2) + (𝑦↑2))) |
| 84 | 83 | ex 417 |
. . 3
⊢ ((𝑎 ∈ ℤ ∧ 𝑏 ∈ ℤ) → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ0 ∃𝑦 ∈ ℕ0
𝑃 = ((𝑥↑2) + (𝑦↑2)))) |
| 85 | 84 | rexlimivv 3213 |
. 2
⊢
(∃𝑎 ∈
ℤ ∃𝑏 ∈
ℤ 𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ0 ∃𝑦 ∈ ℕ0
𝑃 = ((𝑥↑2) + (𝑦↑2))) |
| 86 | 1, 85 | syl 18 |
1
⊢ ((𝑃 ∈ ℙ ∧ (𝑃 mod 4) = 1) → ∃𝑥 ∈ ℕ0
∃𝑦 ∈
ℕ0 𝑃 =
((𝑥↑2) + (𝑦↑2))) |