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 109 |
. . . . . . 7
⊢ (((𝑥 gcd 𝑦) = 1 ∧ 𝑧 = ((𝑥↑2) + (𝑦↑2))) → 𝑧 = ((𝑥↑2) + (𝑦↑2))) |
3 | 2 | reximi 2567 |
. . . . . 6
⊢
(∃𝑦 ∈
ℤ ((𝑥 gcd 𝑦) = 1 ∧ 𝑧 = ((𝑥↑2) + (𝑦↑2))) → ∃𝑦 ∈ ℤ 𝑧 = ((𝑥↑2) + (𝑦↑2))) |
4 | 3 | reximi 2567 |
. . . . 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 13745 |
. . . . 5
⊢ (𝑧 ∈ 𝑆 ↔ ∃𝑥 ∈ ℤ ∃𝑦 ∈ ℤ 𝑧 = ((𝑥↑2) + (𝑦↑2))) |
7 | 4, 6 | sylibr 133 |
. . . 4
⊢
(∃𝑥 ∈
ℤ ∃𝑦 ∈
ℤ ((𝑥 gcd 𝑦) = 1 ∧ 𝑧 = ((𝑥↑2) + (𝑦↑2))) → 𝑧 ∈ 𝑆) |
8 | | 1ne0 8946 |
. . . . . . . . . 10
⊢ 1 ≠
0 |
9 | | gcdeq0 11932 |
. . . . . . . . . . . . 13
⊢ ((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) → ((𝑥 gcd 𝑦) = 0 ↔ (𝑥 = 0 ∧ 𝑦 = 0))) |
10 | 9 | adantr 274 |
. . . . . . . . . . . 12
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → ((𝑥 gcd 𝑦) = 0 ↔ (𝑥 = 0 ∧ 𝑦 = 0))) |
11 | | simpr 109 |
. . . . . . . . . . . . 13
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (𝑥 gcd 𝑦) = 1) |
12 | 11 | eqeq1d 2179 |
. . . . . . . . . . . 12
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → ((𝑥 gcd 𝑦) = 0 ↔ 1 = 0)) |
13 | 10, 12 | bitr3d 189 |
. . . . . . . . . . 11
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → ((𝑥 = 0 ∧ 𝑦 = 0) ↔ 1 = 0)) |
14 | 13 | necon3bbid 2380 |
. . . . . . . . . 10
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (¬ (𝑥 = 0 ∧ 𝑦 = 0) ↔ 1 ≠ 0)) |
15 | 8, 14 | mpbiri 167 |
. . . . . . . . 9
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → ¬ (𝑥 = 0 ∧ 𝑦 = 0)) |
16 | | zsqcl2 10553 |
. . . . . . . . . . . . 13
⊢ (𝑥 ∈ ℤ → (𝑥↑2) ∈
ℕ0) |
17 | 16 | ad2antrr 485 |
. . . . . . . . . . . 12
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (𝑥↑2) ∈
ℕ0) |
18 | 17 | nn0red 9189 |
. . . . . . . . . . 11
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (𝑥↑2) ∈ ℝ) |
19 | 17 | nn0ge0d 9191 |
. . . . . . . . . . 11
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → 0 ≤ (𝑥↑2)) |
20 | | zsqcl2 10553 |
. . . . . . . . . . . . 13
⊢ (𝑦 ∈ ℤ → (𝑦↑2) ∈
ℕ0) |
21 | 20 | ad2antlr 486 |
. . . . . . . . . . . 12
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (𝑦↑2) ∈
ℕ0) |
22 | 21 | nn0red 9189 |
. . . . . . . . . . 11
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (𝑦↑2) ∈ ℝ) |
23 | 21 | nn0ge0d 9191 |
. . . . . . . . . . 11
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → 0 ≤ (𝑦↑2)) |
24 | | add20 8393 |
. . . . . . . . . . 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 1234 |
. . . . . . . . . 10
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (((𝑥↑2) + (𝑦↑2)) = 0 ↔ ((𝑥↑2) = 0 ∧ (𝑦↑2) = 0))) |
26 | | zcn 9217 |
. . . . . . . . . . . 12
⊢ (𝑥 ∈ ℤ → 𝑥 ∈
ℂ) |
27 | 26 | ad2antrr 485 |
. . . . . . . . . . 11
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → 𝑥 ∈ ℂ) |
28 | | zcn 9217 |
. . . . . . . . . . . 12
⊢ (𝑦 ∈ ℤ → 𝑦 ∈
ℂ) |
29 | 28 | ad2antlr 486 |
. . . . . . . . . . 11
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → 𝑦 ∈ ℂ) |
30 | | sqeq0 10539 |
. . . . . . . . . . . 12
⊢ (𝑥 ∈ ℂ → ((𝑥↑2) = 0 ↔ 𝑥 = 0)) |
31 | | sqeq0 10539 |
. . . . . . . . . . . 12
⊢ (𝑦 ∈ ℂ → ((𝑦↑2) = 0 ↔ 𝑦 = 0)) |
32 | 30, 31 | bi2anan9 601 |
. . . . . . . . . . 11
⊢ ((𝑥 ∈ ℂ ∧ 𝑦 ∈ ℂ) → (((𝑥↑2) = 0 ∧ (𝑦↑2) = 0) ↔ (𝑥 = 0 ∧ 𝑦 = 0))) |
33 | 27, 29, 32 | syl2anc 409 |
. . . . . . . . . 10
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (((𝑥↑2) = 0 ∧ (𝑦↑2) = 0) ↔ (𝑥 = 0 ∧ 𝑦 = 0))) |
34 | 25, 33 | bitrd 187 |
. . . . . . . . 9
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (((𝑥↑2) + (𝑦↑2)) = 0 ↔ (𝑥 = 0 ∧ 𝑦 = 0))) |
35 | 15, 34 | mtbird 668 |
. . . . . . . 8
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → ¬ ((𝑥↑2) + (𝑦↑2)) = 0) |
36 | | nn0addcl 9170 |
. . . . . . . . . . 11
⊢ (((𝑥↑2) ∈
ℕ0 ∧ (𝑦↑2) ∈ ℕ0) →
((𝑥↑2) + (𝑦↑2)) ∈
ℕ0) |
37 | 16, 20, 36 | syl2an 287 |
. . . . . . . . . 10
⊢ ((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) → ((𝑥↑2) + (𝑦↑2)) ∈
ℕ0) |
38 | 37 | adantr 274 |
. . . . . . . . 9
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → ((𝑥↑2) + (𝑦↑2)) ∈
ℕ0) |
39 | | elnn0 9137 |
. . . . . . . . 9
⊢ (((𝑥↑2) + (𝑦↑2)) ∈ ℕ0 ↔
(((𝑥↑2) + (𝑦↑2)) ∈ ℕ ∨
((𝑥↑2) + (𝑦↑2)) = 0)) |
40 | 38, 39 | sylib 121 |
. . . . . . . 8
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (((𝑥↑2) + (𝑦↑2)) ∈ ℕ ∨ ((𝑥↑2) + (𝑦↑2)) = 0)) |
41 | 35, 40 | ecased 1344 |
. . . . . . 7
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → ((𝑥↑2) + (𝑦↑2)) ∈ ℕ) |
42 | | eleq1 2233 |
. . . . . . 7
⊢ (𝑧 = ((𝑥↑2) + (𝑦↑2)) → (𝑧 ∈ ℕ ↔ ((𝑥↑2) + (𝑦↑2)) ∈ ℕ)) |
43 | 41, 42 | syl5ibrcom 156 |
. . . . . 6
⊢ (((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) ∧ (𝑥 gcd 𝑦) = 1) → (𝑧 = ((𝑥↑2) + (𝑦↑2)) → 𝑧 ∈ ℕ)) |
44 | 43 | expimpd 361 |
. . . . 5
⊢ ((𝑥 ∈ ℤ ∧ 𝑦 ∈ ℤ) → (((𝑥 gcd 𝑦) = 1 ∧ 𝑧 = ((𝑥↑2) + (𝑦↑2))) → 𝑧 ∈ ℕ)) |
45 | 44 | rexlimivv 2593 |
. . . 4
⊢
(∃𝑥 ∈
ℤ ∃𝑦 ∈
ℤ ((𝑥 gcd 𝑦) = 1 ∧ 𝑧 = ((𝑥↑2) + (𝑦↑2))) → 𝑧 ∈ ℕ) |
46 | 7, 45 | elind 3312 |
. . 3
⊢
(∃𝑥 ∈
ℤ ∃𝑦 ∈
ℤ ((𝑥 gcd 𝑦) = 1 ∧ 𝑧 = ((𝑥↑2) + (𝑦↑2))) → 𝑧 ∈ (𝑆 ∩ ℕ)) |
47 | 46 | abssi 3222 |
. 2
⊢ {𝑧 ∣ ∃𝑥 ∈ ℤ ∃𝑦 ∈ ℤ ((𝑥 gcd 𝑦) = 1 ∧ 𝑧 = ((𝑥↑2) + (𝑦↑2)))} ⊆ (𝑆 ∩ ℕ) |
48 | 1, 47 | eqsstri 3179 |
1
⊢ 𝑌 ⊆ (𝑆 ∩ ℕ) |