| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | 2sqnn0 27482 | . 2
⊢ ((𝑃 ∈ ℙ ∧ (𝑃 mod 4) = 1) → ∃𝑎 ∈ ℕ0
∃𝑏 ∈
ℕ0 𝑃 =
((𝑎↑2) + (𝑏↑2))) | 
| 2 |  | elnn0 12528 | . . . . . . 7
⊢ (𝑎 ∈ ℕ0
↔ (𝑎 ∈ ℕ
∨ 𝑎 =
0)) | 
| 3 |  | elnn0 12528 | . . . . . . . . 9
⊢ (𝑏 ∈ ℕ0
↔ (𝑏 ∈ ℕ
∨ 𝑏 =
0)) | 
| 4 |  | oveq1 7438 | . . . . . . . . . . . . . . . . 17
⊢ (𝑥 = 𝑎 → (𝑥↑2) = (𝑎↑2)) | 
| 5 | 4 | oveq1d 7446 | . . . . . . . . . . . . . . . 16
⊢ (𝑥 = 𝑎 → ((𝑥↑2) + (𝑦↑2)) = ((𝑎↑2) + (𝑦↑2))) | 
| 6 | 5 | eqeq2d 2748 | . . . . . . . . . . . . . . 15
⊢ (𝑥 = 𝑎 → (𝑃 = ((𝑥↑2) + (𝑦↑2)) ↔ 𝑃 = ((𝑎↑2) + (𝑦↑2)))) | 
| 7 |  | oveq1 7438 | . . . . . . . . . . . . . . . . 17
⊢ (𝑦 = 𝑏 → (𝑦↑2) = (𝑏↑2)) | 
| 8 | 7 | oveq2d 7447 | . . . . . . . . . . . . . . . 16
⊢ (𝑦 = 𝑏 → ((𝑎↑2) + (𝑦↑2)) = ((𝑎↑2) + (𝑏↑2))) | 
| 9 | 8 | eqeq2d 2748 | . . . . . . . . . . . . . . 15
⊢ (𝑦 = 𝑏 → (𝑃 = ((𝑎↑2) + (𝑦↑2)) ↔ 𝑃 = ((𝑎↑2) + (𝑏↑2)))) | 
| 10 | 6, 9 | rspc2ev 3635 | . . . . . . . . . . . . . 14
⊢ ((𝑎 ∈ ℕ ∧ 𝑏 ∈ ℕ ∧ 𝑃 = ((𝑎↑2) + (𝑏↑2))) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2))) | 
| 11 | 10 | 3expia 1122 | . . . . . . . . . . . . 13
⊢ ((𝑎 ∈ ℕ ∧ 𝑏 ∈ ℕ) → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2)))) | 
| 12 | 11 | a1d 25 | . . . . . . . . . . . 12
⊢ ((𝑎 ∈ ℕ ∧ 𝑏 ∈ ℕ) → (𝑃 ∈ ℙ → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2))))) | 
| 13 | 12 | expcom 413 | . . . . . . . . . . 11
⊢ (𝑏 ∈ ℕ → (𝑎 ∈ ℕ → (𝑃 ∈ ℙ → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2)))))) | 
| 14 |  | sq0i 14232 | . . . . . . . . . . . . . . . . . 18
⊢ (𝑎 = 0 → (𝑎↑2) = 0) | 
| 15 | 14 | adantr 480 | . . . . . . . . . . . . . . . . 17
⊢ ((𝑎 = 0 ∧ 𝑏 ∈ ℕ) → (𝑎↑2) = 0) | 
| 16 | 15 | oveq1d 7446 | . . . . . . . . . . . . . . . 16
⊢ ((𝑎 = 0 ∧ 𝑏 ∈ ℕ) → ((𝑎↑2) + (𝑏↑2)) = (0 + (𝑏↑2))) | 
| 17 |  | nncn 12274 | . . . . . . . . . . . . . . . . . . 19
⊢ (𝑏 ∈ ℕ → 𝑏 ∈
ℂ) | 
| 18 | 17 | sqcld 14184 | . . . . . . . . . . . . . . . . . 18
⊢ (𝑏 ∈ ℕ → (𝑏↑2) ∈
ℂ) | 
| 19 | 18 | addlidd 11462 | . . . . . . . . . . . . . . . . 17
⊢ (𝑏 ∈ ℕ → (0 +
(𝑏↑2)) = (𝑏↑2)) | 
| 20 | 19 | adantl 481 | . . . . . . . . . . . . . . . 16
⊢ ((𝑎 = 0 ∧ 𝑏 ∈ ℕ) → (0 + (𝑏↑2)) = (𝑏↑2)) | 
| 21 | 16, 20 | eqtrd 2777 | . . . . . . . . . . . . . . 15
⊢ ((𝑎 = 0 ∧ 𝑏 ∈ ℕ) → ((𝑎↑2) + (𝑏↑2)) = (𝑏↑2)) | 
| 22 | 21 | eqeq2d 2748 | . . . . . . . . . . . . . 14
⊢ ((𝑎 = 0 ∧ 𝑏 ∈ ℕ) → (𝑃 = ((𝑎↑2) + (𝑏↑2)) ↔ 𝑃 = (𝑏↑2))) | 
| 23 |  | eleq1 2829 | . . . . . . . . . . . . . . . . . 18
⊢ (𝑃 = (𝑏↑2) → (𝑃 ∈ ℙ ↔ (𝑏↑2) ∈ ℙ)) | 
| 24 | 23 | adantl 481 | . . . . . . . . . . . . . . . . 17
⊢ ((𝑏 ∈ ℕ ∧ 𝑃 = (𝑏↑2)) → (𝑃 ∈ ℙ ↔ (𝑏↑2) ∈ ℙ)) | 
| 25 |  | nnz 12634 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑏 ∈ ℕ → 𝑏 ∈
ℤ) | 
| 26 |  | sqnprm 16739 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑏 ∈ ℤ → ¬
(𝑏↑2) ∈
ℙ) | 
| 27 | 25, 26 | syl 17 | . . . . . . . . . . . . . . . . . . 19
⊢ (𝑏 ∈ ℕ → ¬
(𝑏↑2) ∈
ℙ) | 
| 28 | 27 | pm2.21d 121 | . . . . . . . . . . . . . . . . . 18
⊢ (𝑏 ∈ ℕ → ((𝑏↑2) ∈ ℙ →
∃𝑥 ∈ ℕ
∃𝑦 ∈ ℕ
𝑃 = ((𝑥↑2) + (𝑦↑2)))) | 
| 29 | 28 | adantr 480 | . . . . . . . . . . . . . . . . 17
⊢ ((𝑏 ∈ ℕ ∧ 𝑃 = (𝑏↑2)) → ((𝑏↑2) ∈ ℙ → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2)))) | 
| 30 | 24, 29 | sylbid 240 | . . . . . . . . . . . . . . . 16
⊢ ((𝑏 ∈ ℕ ∧ 𝑃 = (𝑏↑2)) → (𝑃 ∈ ℙ → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2)))) | 
| 31 | 30 | ex 412 | . . . . . . . . . . . . . . 15
⊢ (𝑏 ∈ ℕ → (𝑃 = (𝑏↑2) → (𝑃 ∈ ℙ → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2))))) | 
| 32 | 31 | adantl 481 | . . . . . . . . . . . . . 14
⊢ ((𝑎 = 0 ∧ 𝑏 ∈ ℕ) → (𝑃 = (𝑏↑2) → (𝑃 ∈ ℙ → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2))))) | 
| 33 | 22, 32 | sylbid 240 | . . . . . . . . . . . . 13
⊢ ((𝑎 = 0 ∧ 𝑏 ∈ ℕ) → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → (𝑃 ∈ ℙ → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2))))) | 
| 34 | 33 | com23 86 | . . . . . . . . . . . 12
⊢ ((𝑎 = 0 ∧ 𝑏 ∈ ℕ) → (𝑃 ∈ ℙ → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2))))) | 
| 35 | 34 | expcom 413 | . . . . . . . . . . 11
⊢ (𝑏 ∈ ℕ → (𝑎 = 0 → (𝑃 ∈ ℙ → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2)))))) | 
| 36 | 13, 35 | jaod 860 | . . . . . . . . . 10
⊢ (𝑏 ∈ ℕ → ((𝑎 ∈ ℕ ∨ 𝑎 = 0) → (𝑃 ∈ ℙ → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2)))))) | 
| 37 |  | sq0i 14232 | . . . . . . . . . . . . . . . . . 18
⊢ (𝑏 = 0 → (𝑏↑2) = 0) | 
| 38 | 37 | adantr 480 | . . . . . . . . . . . . . . . . 17
⊢ ((𝑏 = 0 ∧ 𝑎 ∈ ℕ) → (𝑏↑2) = 0) | 
| 39 | 38 | oveq2d 7447 | . . . . . . . . . . . . . . . 16
⊢ ((𝑏 = 0 ∧ 𝑎 ∈ ℕ) → ((𝑎↑2) + (𝑏↑2)) = ((𝑎↑2) + 0)) | 
| 40 |  | nncn 12274 | . . . . . . . . . . . . . . . . . . 19
⊢ (𝑎 ∈ ℕ → 𝑎 ∈
ℂ) | 
| 41 | 40 | sqcld 14184 | . . . . . . . . . . . . . . . . . 18
⊢ (𝑎 ∈ ℕ → (𝑎↑2) ∈
ℂ) | 
| 42 | 41 | addridd 11461 | . . . . . . . . . . . . . . . . 17
⊢ (𝑎 ∈ ℕ → ((𝑎↑2) + 0) = (𝑎↑2)) | 
| 43 | 42 | adantl 481 | . . . . . . . . . . . . . . . 16
⊢ ((𝑏 = 0 ∧ 𝑎 ∈ ℕ) → ((𝑎↑2) + 0) = (𝑎↑2)) | 
| 44 | 39, 43 | eqtrd 2777 | . . . . . . . . . . . . . . 15
⊢ ((𝑏 = 0 ∧ 𝑎 ∈ ℕ) → ((𝑎↑2) + (𝑏↑2)) = (𝑎↑2)) | 
| 45 | 44 | eqeq2d 2748 | . . . . . . . . . . . . . 14
⊢ ((𝑏 = 0 ∧ 𝑎 ∈ ℕ) → (𝑃 = ((𝑎↑2) + (𝑏↑2)) ↔ 𝑃 = (𝑎↑2))) | 
| 46 |  | eleq1 2829 | . . . . . . . . . . . . . . . . . 18
⊢ (𝑃 = (𝑎↑2) → (𝑃 ∈ ℙ ↔ (𝑎↑2) ∈ ℙ)) | 
| 47 | 46 | adantl 481 | . . . . . . . . . . . . . . . . 17
⊢ ((𝑎 ∈ ℕ ∧ 𝑃 = (𝑎↑2)) → (𝑃 ∈ ℙ ↔ (𝑎↑2) ∈ ℙ)) | 
| 48 |  | nnz 12634 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑎 ∈ ℕ → 𝑎 ∈
ℤ) | 
| 49 |  | sqnprm 16739 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑎 ∈ ℤ → ¬
(𝑎↑2) ∈
ℙ) | 
| 50 | 48, 49 | syl 17 | . . . . . . . . . . . . . . . . . . 19
⊢ (𝑎 ∈ ℕ → ¬
(𝑎↑2) ∈
ℙ) | 
| 51 | 50 | pm2.21d 121 | . . . . . . . . . . . . . . . . . 18
⊢ (𝑎 ∈ ℕ → ((𝑎↑2) ∈ ℙ →
∃𝑥 ∈ ℕ
∃𝑦 ∈ ℕ
𝑃 = ((𝑥↑2) + (𝑦↑2)))) | 
| 52 | 51 | adantr 480 | . . . . . . . . . . . . . . . . 17
⊢ ((𝑎 ∈ ℕ ∧ 𝑃 = (𝑎↑2)) → ((𝑎↑2) ∈ ℙ → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2)))) | 
| 53 | 47, 52 | sylbid 240 | . . . . . . . . . . . . . . . 16
⊢ ((𝑎 ∈ ℕ ∧ 𝑃 = (𝑎↑2)) → (𝑃 ∈ ℙ → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2)))) | 
| 54 | 53 | ex 412 | . . . . . . . . . . . . . . 15
⊢ (𝑎 ∈ ℕ → (𝑃 = (𝑎↑2) → (𝑃 ∈ ℙ → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2))))) | 
| 55 | 54 | adantl 481 | . . . . . . . . . . . . . 14
⊢ ((𝑏 = 0 ∧ 𝑎 ∈ ℕ) → (𝑃 = (𝑎↑2) → (𝑃 ∈ ℙ → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2))))) | 
| 56 | 45, 55 | sylbid 240 | . . . . . . . . . . . . 13
⊢ ((𝑏 = 0 ∧ 𝑎 ∈ ℕ) → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → (𝑃 ∈ ℙ → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2))))) | 
| 57 | 56 | com23 86 | . . . . . . . . . . . 12
⊢ ((𝑏 = 0 ∧ 𝑎 ∈ ℕ) → (𝑃 ∈ ℙ → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2))))) | 
| 58 | 57 | ex 412 | . . . . . . . . . . 11
⊢ (𝑏 = 0 → (𝑎 ∈ ℕ → (𝑃 ∈ ℙ → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2)))))) | 
| 59 | 14, 37 | oveqan12rd 7451 | . . . . . . . . . . . . . . . 16
⊢ ((𝑏 = 0 ∧ 𝑎 = 0) → ((𝑎↑2) + (𝑏↑2)) = (0 + 0)) | 
| 60 |  | 00id 11436 | . . . . . . . . . . . . . . . 16
⊢ (0 + 0) =
0 | 
| 61 | 59, 60 | eqtrdi 2793 | . . . . . . . . . . . . . . 15
⊢ ((𝑏 = 0 ∧ 𝑎 = 0) → ((𝑎↑2) + (𝑏↑2)) = 0) | 
| 62 | 61 | eqeq2d 2748 | . . . . . . . . . . . . . 14
⊢ ((𝑏 = 0 ∧ 𝑎 = 0) → (𝑃 = ((𝑎↑2) + (𝑏↑2)) ↔ 𝑃 = 0)) | 
| 63 |  | eleq1 2829 | . . . . . . . . . . . . . . 15
⊢ (𝑃 = 0 → (𝑃 ∈ ℙ ↔ 0 ∈
ℙ)) | 
| 64 |  | 0nprm 16715 | . . . . . . . . . . . . . . . 16
⊢  ¬ 0
∈ ℙ | 
| 65 | 64 | pm2.21i 119 | . . . . . . . . . . . . . . 15
⊢ (0 ∈
ℙ → ∃𝑥
∈ ℕ ∃𝑦
∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2))) | 
| 66 | 63, 65 | biimtrdi 253 | . . . . . . . . . . . . . 14
⊢ (𝑃 = 0 → (𝑃 ∈ ℙ → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2)))) | 
| 67 | 62, 66 | biimtrdi 253 | . . . . . . . . . . . . 13
⊢ ((𝑏 = 0 ∧ 𝑎 = 0) → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → (𝑃 ∈ ℙ → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2))))) | 
| 68 | 67 | com23 86 | . . . . . . . . . . . 12
⊢ ((𝑏 = 0 ∧ 𝑎 = 0) → (𝑃 ∈ ℙ → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2))))) | 
| 69 | 68 | ex 412 | . . . . . . . . . . 11
⊢ (𝑏 = 0 → (𝑎 = 0 → (𝑃 ∈ ℙ → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2)))))) | 
| 70 | 58, 69 | jaod 860 | . . . . . . . . . 10
⊢ (𝑏 = 0 → ((𝑎 ∈ ℕ ∨ 𝑎 = 0) → (𝑃 ∈ ℙ → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2)))))) | 
| 71 | 36, 70 | jaoi 858 | . . . . . . . . 9
⊢ ((𝑏 ∈ ℕ ∨ 𝑏 = 0) → ((𝑎 ∈ ℕ ∨ 𝑎 = 0) → (𝑃 ∈ ℙ → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2)))))) | 
| 72 | 3, 71 | sylbi 217 | . . . . . . . 8
⊢ (𝑏 ∈ ℕ0
→ ((𝑎 ∈ ℕ
∨ 𝑎 = 0) → (𝑃 ∈ ℙ → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2)))))) | 
| 73 | 72 | com12 32 | . . . . . . 7
⊢ ((𝑎 ∈ ℕ ∨ 𝑎 = 0) → (𝑏 ∈ ℕ0 → (𝑃 ∈ ℙ → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2)))))) | 
| 74 | 2, 73 | sylbi 217 | . . . . . 6
⊢ (𝑎 ∈ ℕ0
→ (𝑏 ∈
ℕ0 → (𝑃 ∈ ℙ → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2)))))) | 
| 75 | 74 | imp 406 | . . . . 5
⊢ ((𝑎 ∈ ℕ0
∧ 𝑏 ∈
ℕ0) → (𝑃 ∈ ℙ → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2))))) | 
| 76 | 75 | com12 32 | . . . 4
⊢ (𝑃 ∈ ℙ → ((𝑎 ∈ ℕ0
∧ 𝑏 ∈
ℕ0) → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2))))) | 
| 77 | 76 | adantr 480 | . . 3
⊢ ((𝑃 ∈ ℙ ∧ (𝑃 mod 4) = 1) → ((𝑎 ∈ ℕ0
∧ 𝑏 ∈
ℕ0) → (𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2))))) | 
| 78 | 77 | rexlimdvv 3212 | . 2
⊢ ((𝑃 ∈ ℙ ∧ (𝑃 mod 4) = 1) →
(∃𝑎 ∈
ℕ0 ∃𝑏 ∈ ℕ0 𝑃 = ((𝑎↑2) + (𝑏↑2)) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2)))) | 
| 79 | 1, 78 | mpd 15 | 1
⊢ ((𝑃 ∈ ℙ ∧ (𝑃 mod 4) = 1) → ∃𝑥 ∈ ℕ ∃𝑦 ∈ ℕ 𝑃 = ((𝑥↑2) + (𝑦↑2))) |