Proof of Theorem 2sqlem7
Step | Hyp | Ref
| Expression |
1 | | 2sqlem7.2 |
. 2
⊢ 𝑌 = {𝑧 ∣ ∃𝑥 ∈ ℤ ∃𝑦 ∈ ℤ ((𝑥 gcd 𝑦) = 1 ∧ 𝑧 = ((𝑥↑2) + (𝑦↑2)))} |
2 | | simpr 484 |
. . . . . . 7
⊢ (((𝑥 gcd 𝑦) = 1 ∧ 𝑧 = ((𝑥↑2) + (𝑦↑2))) → 𝑧 = ((𝑥↑2) + (𝑦↑2))) |
3 | 2 | reximi 3174 |
. . . . . 6
⊢
(∃𝑦 ∈
ℤ ((𝑥 gcd 𝑦) = 1 ∧ 𝑧 = ((𝑥↑2) + (𝑦↑2))) → ∃𝑦 ∈ ℤ 𝑧 = ((𝑥↑2) + (𝑦↑2))) |
4 | 3 | reximi 3174 |
. . . . 5
⊢
(∃𝑥 ∈
ℤ ∃𝑦 ∈
ℤ ((𝑥 gcd 𝑦) = 1 ∧ 𝑧 = ((𝑥↑2) + (𝑦↑2))) → ∃𝑥 ∈ ℤ ∃𝑦 ∈ ℤ 𝑧 = ((𝑥↑2) + (𝑦↑2))) |
5 | | 2sq.1 |
. . . . . 6
⊢ 𝑆 = ran (𝑤 ∈ ℤ[i] ↦ ((abs‘𝑤)↑2)) |
6 | 5 | 2sqlem2 26471 |
. . . . 5
⊢ (𝑧 ∈ 𝑆 ↔ ∃𝑥 ∈ ℤ ∃𝑦 ∈ ℤ 𝑧 = ((𝑥↑2) + (𝑦↑2))) |
7 | 4, 6 | sylibr 233 |
. . . 4
⊢
(∃𝑥 ∈
ℤ ∃𝑦 ∈
ℤ ((𝑥 gcd 𝑦) = 1 ∧ 𝑧 = ((𝑥↑2) + (𝑦↑2))) → 𝑧 ∈ 𝑆) |
8 | | ax-1ne0 10871 |
. . . . . . . . . 10
⊢ 1 ≠
0 |
9 | | gcdeq0 16152 |
. . . . . . . . . . . . 13
⊢ ((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) → ((𝑥 gcd 𝑦) = 0 ↔ (𝑥 = 0 ∧ 𝑦 = 0))) |
10 | 9 | adantr 480 |
. . . . . . . . . . . 12
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → ((𝑥 gcd 𝑦) = 0 ↔ (𝑥 = 0 ∧ 𝑦 = 0))) |
11 | | simpr 484 |
. . . . . . . . . . . . 13
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (𝑥 gcd 𝑦) = 1) |
12 | 11 | eqeq1d 2740 |
. . . . . . . . . . . 12
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → ((𝑥 gcd 𝑦) = 0 ↔ 1 = 0)) |
13 | 10, 12 | bitr3d 280 |
. . . . . . . . . . 11
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → ((𝑥 = 0 ∧ 𝑦 = 0) ↔ 1 = 0)) |
14 | 13 | necon3bbid 2980 |
. . . . . . . . . 10
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (¬ (𝑥 = 0 ∧ 𝑦 = 0) ↔ 1 ≠ 0)) |
15 | 8, 14 | mpbiri 257 |
. . . . . . . . 9
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → ¬ (𝑥 = 0 ∧ 𝑦 = 0)) |
16 | | zsqcl2 13784 |
. . . . . . . . . . . . 13
⊢ (𝑥 ∈ ℤ → (𝑥↑2) ∈
ℕ0) |
17 | 16 | ad2antrr 722 |
. . . . . . . . . . . 12
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (𝑥↑2) ∈
ℕ0) |
18 | 17 | nn0red 12224 |
. . . . . . . . . . 11
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (𝑥↑2) ∈ ℝ) |
19 | 17 | nn0ge0d 12226 |
. . . . . . . . . . 11
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → 0 ≤ (𝑥↑2)) |
20 | | zsqcl2 13784 |
. . . . . . . . . . . . 13
⊢ (𝑦 ∈ ℤ → (𝑦↑2) ∈
ℕ0) |
21 | 20 | ad2antlr 723 |
. . . . . . . . . . . 12
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (𝑦↑2) ∈
ℕ0) |
22 | 21 | nn0red 12224 |
. . . . . . . . . . 11
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (𝑦↑2) ∈ ℝ) |
23 | 21 | nn0ge0d 12226 |
. . . . . . . . . . 11
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → 0 ≤ (𝑦↑2)) |
24 | | add20 11417 |
. . . . . . . . . . 11
⊢ ((((𝑥↑2) ∈ ℝ ∧ 0
≤ (𝑥↑2)) ∧
((𝑦↑2) ∈ ℝ
∧ 0 ≤ (𝑦↑2)))
→ (((𝑥↑2) +
(𝑦↑2)) = 0 ↔
((𝑥↑2) = 0 ∧
(𝑦↑2) =
0))) |
25 | 18, 19, 22, 23, 24 | syl22anc 835 |
. . . . . . . . . 10
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (((𝑥↑2) + (𝑦↑2)) = 0 ↔ ((𝑥↑2) = 0 ∧ (𝑦↑2) = 0))) |
26 | | zcn 12254 |
. . . . . . . . . . . 12
⊢ (𝑥 ∈ ℤ → 𝑥 ∈
ℂ) |
27 | 26 | ad2antrr 722 |
. . . . . . . . . . 11
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → 𝑥 ∈ ℂ) |
28 | | zcn 12254 |
. . . . . . . . . . . 12
⊢ (𝑦 ∈ ℤ → 𝑦 ∈
ℂ) |
29 | 28 | ad2antlr 723 |
. . . . . . . . . . 11
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → 𝑦 ∈ ℂ) |
30 | | sqeq0 13768 |
. . . . . . . . . . . 12
⊢ (𝑥 ∈ ℂ → ((𝑥↑2) = 0 ↔ 𝑥 = 0)) |
31 | | sqeq0 13768 |
. . . . . . . . . . . 12
⊢ (𝑦 ∈ ℂ → ((𝑦↑2) = 0 ↔ 𝑦 = 0)) |
32 | 30, 31 | bi2anan9 635 |
. . . . . . . . . . 11
⊢ ((𝑥 ∈ ℂ ∧ 𝑦 ∈ ℂ) → (((𝑥↑2) = 0 ∧ (𝑦↑2) = 0) ↔ (𝑥 = 0 ∧ 𝑦 = 0))) |
33 | 27, 29, 32 | syl2anc 583 |
. . . . . . . . . 10
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (((𝑥↑2) = 0 ∧ (𝑦↑2) = 0) ↔ (𝑥 = 0 ∧ 𝑦 = 0))) |
34 | 25, 33 | bitrd 278 |
. . . . . . . . 9
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (((𝑥↑2) + (𝑦↑2)) = 0 ↔ (𝑥 = 0 ∧ 𝑦 = 0))) |
35 | 15, 34 | mtbird 324 |
. . . . . . . 8
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → ¬ ((𝑥↑2) + (𝑦↑2)) = 0) |
36 | | nn0addcl 12198 |
. . . . . . . . . . . 12
⊢ (((𝑥↑2) ∈
ℕ0 ∧ (𝑦↑2) ∈ ℕ0) →
((𝑥↑2) + (𝑦↑2)) ∈
ℕ0) |
37 | 16, 20, 36 | syl2an 595 |
. . . . . . . . . . 11
⊢ ((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) → ((𝑥↑2) + (𝑦↑2)) ∈
ℕ0) |
38 | 37 | adantr 480 |
. . . . . . . . . 10
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → ((𝑥↑2) + (𝑦↑2)) ∈
ℕ0) |
39 | | elnn0 12165 |
. . . . . . . . . 10
⊢ (((𝑥↑2) + (𝑦↑2)) ∈ ℕ0 ↔
(((𝑥↑2) + (𝑦↑2)) ∈ ℕ ∨
((𝑥↑2) + (𝑦↑2)) = 0)) |
40 | 38, 39 | sylib 217 |
. . . . . . . . 9
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (((𝑥↑2) + (𝑦↑2)) ∈ ℕ ∨ ((𝑥↑2) + (𝑦↑2)) = 0)) |
41 | 40 | ord 860 |
. . . . . . . 8
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (¬ ((𝑥↑2) + (𝑦↑2)) ∈ ℕ → ((𝑥↑2) + (𝑦↑2)) = 0)) |
42 | 35, 41 | mt3d 148 |
. . . . . . 7
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → ((𝑥↑2) + (𝑦↑2)) ∈ ℕ) |
43 | | eleq1 2826 |
. . . . . . 7
⊢ (𝑧 = ((𝑥↑2) + (𝑦↑2)) → (𝑧 ∈ ℕ ↔ ((𝑥↑2) + (𝑦↑2)) ∈ ℕ)) |
44 | 42, 43 | syl5ibrcom 246 |
. . . . . 6
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (𝑧 = ((𝑥↑2) + (𝑦↑2)) → 𝑧 ∈ ℕ)) |
45 | 44 | expimpd 453 |
. . . . 5
⊢ ((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) → (((𝑥 gcd 𝑦) = 1 ∧ 𝑧 = ((𝑥↑2) + (𝑦↑2))) → 𝑧 ∈ ℕ)) |
46 | 45 | rexlimivv 3220 |
. . . 4
⊢
(∃𝑥 ∈
ℤ ∃𝑦 ∈
ℤ ((𝑥 gcd 𝑦) = 1 ∧ 𝑧 = ((𝑥↑2) + (𝑦↑2))) → 𝑧 ∈ ℕ) |
47 | 7, 46 | elind 4124 |
. . 3
⊢
(∃𝑥 ∈
ℤ ∃𝑦 ∈
ℤ ((𝑥 gcd 𝑦) = 1 ∧ 𝑧 = ((𝑥↑2) + (𝑦↑2))) → 𝑧 ∈ (𝑆 ∩ ℕ)) |
48 | 47 | abssi 3999 |
. 2
⊢ {𝑧 ∣ ∃𝑥 ∈ ℤ ∃𝑦 ∈ ℤ ((𝑥 gcd 𝑦) = 1 ∧ 𝑧 = ((𝑥↑2) + (𝑦↑2)))} ⊆ (𝑆 ∩ ℕ) |
49 | 1, 48 | eqsstri 3951 |
1
⊢ 𝑌 ⊆ (𝑆 ∩ ℕ) |