Proof of Theorem dvdssq
| Step | Hyp | Ref
| Expression |
| 1 | | 0z 9354 |
. . . 4
⊢ 0 ∈
ℤ |
| 2 | | zdceq 9418 |
. . . 4
⊢ ((𝑀 ∈ ℤ ∧ 0 ∈
ℤ) → DECID 𝑀 = 0) |
| 3 | 1, 2 | mpan2 425 |
. . 3
⊢ (𝑀 ∈ ℤ →
DECID 𝑀 =
0) |
| 4 | | exmiddc 837 |
. . 3
⊢
(DECID 𝑀 = 0 → (𝑀 = 0 ∨ ¬ 𝑀 = 0)) |
| 5 | | 0dvds 11993 |
. . . . . . . 8
⊢ (𝑁 ∈ ℤ → (0
∥ 𝑁 ↔ 𝑁 = 0)) |
| 6 | | zcn 9348 |
. . . . . . . . 9
⊢ (𝑁 ∈ ℤ → 𝑁 ∈
ℂ) |
| 7 | | sqeq0 10711 |
. . . . . . . . 9
⊢ (𝑁 ∈ ℂ → ((𝑁↑2) = 0 ↔ 𝑁 = 0)) |
| 8 | 6, 7 | syl 14 |
. . . . . . . 8
⊢ (𝑁 ∈ ℤ → ((𝑁↑2) = 0 ↔ 𝑁 = 0)) |
| 9 | 5, 8 | bitr4d 191 |
. . . . . . 7
⊢ (𝑁 ∈ ℤ → (0
∥ 𝑁 ↔ (𝑁↑2) = 0)) |
| 10 | | zsqcl 10719 |
. . . . . . . 8
⊢ (𝑁 ∈ ℤ → (𝑁↑2) ∈
ℤ) |
| 11 | | 0dvds 11993 |
. . . . . . . 8
⊢ ((𝑁↑2) ∈ ℤ →
(0 ∥ (𝑁↑2)
↔ (𝑁↑2) =
0)) |
| 12 | 10, 11 | syl 14 |
. . . . . . 7
⊢ (𝑁 ∈ ℤ → (0
∥ (𝑁↑2) ↔
(𝑁↑2) =
0)) |
| 13 | 9, 12 | bitr4d 191 |
. . . . . 6
⊢ (𝑁 ∈ ℤ → (0
∥ 𝑁 ↔ 0 ∥
(𝑁↑2))) |
| 14 | 13 | adantl 277 |
. . . . 5
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (0
∥ 𝑁 ↔ 0 ∥
(𝑁↑2))) |
| 15 | | breq1 4037 |
. . . . . 6
⊢ (𝑀 = 0 → (𝑀 ∥ 𝑁 ↔ 0 ∥ 𝑁)) |
| 16 | | sq0i 10740 |
. . . . . . 7
⊢ (𝑀 = 0 → (𝑀↑2) = 0) |
| 17 | 16 | breq1d 4044 |
. . . . . 6
⊢ (𝑀 = 0 → ((𝑀↑2) ∥ (𝑁↑2) ↔ 0 ∥ (𝑁↑2))) |
| 18 | 15, 17 | bibi12d 235 |
. . . . 5
⊢ (𝑀 = 0 → ((𝑀 ∥ 𝑁 ↔ (𝑀↑2) ∥ (𝑁↑2)) ↔ (0 ∥ 𝑁 ↔ 0 ∥ (𝑁↑2)))) |
| 19 | 14, 18 | imbitrrid 156 |
. . . 4
⊢ (𝑀 = 0 → ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ 𝑁 ↔ (𝑀↑2) ∥ (𝑁↑2)))) |
| 20 | | df-ne 2368 |
. . . . 5
⊢ (𝑀 ≠ 0 ↔ ¬ 𝑀 = 0) |
| 21 | | nnabscl 11282 |
. . . . . . . . 9
⊢ ((𝑀 ∈ ℤ ∧ 𝑀 ≠ 0) → (abs‘𝑀) ∈
ℕ) |
| 22 | | zdceq 9418 |
. . . . . . . . . . . 12
⊢ ((𝑁 ∈ ℤ ∧ 0 ∈
ℤ) → DECID 𝑁 = 0) |
| 23 | 1, 22 | mpan2 425 |
. . . . . . . . . . 11
⊢ (𝑁 ∈ ℤ →
DECID 𝑁 =
0) |
| 24 | | exmiddc 837 |
. . . . . . . . . . 11
⊢
(DECID 𝑁 = 0 → (𝑁 = 0 ∨ ¬ 𝑁 = 0)) |
| 25 | | nnz 9362 |
. . . . . . . . . . . . . . 15
⊢
((abs‘𝑀)
∈ ℕ → (abs‘𝑀) ∈ ℤ) |
| 26 | | dvds0 11988 |
. . . . . . . . . . . . . . . 16
⊢
((abs‘𝑀)
∈ ℤ → (abs‘𝑀) ∥ 0) |
| 27 | | zsqcl 10719 |
. . . . . . . . . . . . . . . . 17
⊢
((abs‘𝑀)
∈ ℤ → ((abs‘𝑀)↑2) ∈ ℤ) |
| 28 | | dvds0 11988 |
. . . . . . . . . . . . . . . . 17
⊢
(((abs‘𝑀)↑2) ∈ ℤ →
((abs‘𝑀)↑2)
∥ 0) |
| 29 | 27, 28 | syl 14 |
. . . . . . . . . . . . . . . 16
⊢
((abs‘𝑀)
∈ ℤ → ((abs‘𝑀)↑2) ∥ 0) |
| 30 | 26, 29 | 2thd 175 |
. . . . . . . . . . . . . . 15
⊢
((abs‘𝑀)
∈ ℤ → ((abs‘𝑀) ∥ 0 ↔ ((abs‘𝑀)↑2) ∥
0)) |
| 31 | 25, 30 | syl 14 |
. . . . . . . . . . . . . 14
⊢
((abs‘𝑀)
∈ ℕ → ((abs‘𝑀) ∥ 0 ↔ ((abs‘𝑀)↑2) ∥
0)) |
| 32 | 31 | adantr 276 |
. . . . . . . . . . . . 13
⊢
(((abs‘𝑀)
∈ ℕ ∧ 𝑁
∈ ℤ) → ((abs‘𝑀) ∥ 0 ↔ ((abs‘𝑀)↑2) ∥
0)) |
| 33 | | breq2 4038 |
. . . . . . . . . . . . . 14
⊢ (𝑁 = 0 → ((abs‘𝑀) ∥ 𝑁 ↔ (abs‘𝑀) ∥ 0)) |
| 34 | | sq0i 10740 |
. . . . . . . . . . . . . . 15
⊢ (𝑁 = 0 → (𝑁↑2) = 0) |
| 35 | 34 | breq2d 4046 |
. . . . . . . . . . . . . 14
⊢ (𝑁 = 0 → (((abs‘𝑀)↑2) ∥ (𝑁↑2) ↔
((abs‘𝑀)↑2)
∥ 0)) |
| 36 | 33, 35 | bibi12d 235 |
. . . . . . . . . . . . 13
⊢ (𝑁 = 0 → (((abs‘𝑀) ∥ 𝑁 ↔ ((abs‘𝑀)↑2) ∥ (𝑁↑2)) ↔ ((abs‘𝑀) ∥ 0 ↔
((abs‘𝑀)↑2)
∥ 0))) |
| 37 | 32, 36 | imbitrrid 156 |
. . . . . . . . . . . 12
⊢ (𝑁 = 0 → (((abs‘𝑀) ∈ ℕ ∧ 𝑁 ∈ ℤ) →
((abs‘𝑀) ∥
𝑁 ↔ ((abs‘𝑀)↑2) ∥ (𝑁↑2)))) |
| 38 | | df-ne 2368 |
. . . . . . . . . . . . 13
⊢ (𝑁 ≠ 0 ↔ ¬ 𝑁 = 0) |
| 39 | | nnabscl 11282 |
. . . . . . . . . . . . . . . . 17
⊢ ((𝑁 ∈ ℤ ∧ 𝑁 ≠ 0) → (abs‘𝑁) ∈
ℕ) |
| 40 | | dvdssqlem 12222 |
. . . . . . . . . . . . . . . . 17
⊢
(((abs‘𝑀)
∈ ℕ ∧ (abs‘𝑁) ∈ ℕ) → ((abs‘𝑀) ∥ (abs‘𝑁) ↔ ((abs‘𝑀)↑2) ∥
((abs‘𝑁)↑2))) |
| 41 | 39, 40 | sylan2 286 |
. . . . . . . . . . . . . . . 16
⊢
(((abs‘𝑀)
∈ ℕ ∧ (𝑁
∈ ℤ ∧ 𝑁 ≠
0)) → ((abs‘𝑀)
∥ (abs‘𝑁)
↔ ((abs‘𝑀)↑2) ∥ ((abs‘𝑁)↑2))) |
| 42 | | simpl 109 |
. . . . . . . . . . . . . . . . 17
⊢ ((𝑁 ∈ ℤ ∧ 𝑁 ≠ 0) → 𝑁 ∈
ℤ) |
| 43 | | dvdsabsb 11992 |
. . . . . . . . . . . . . . . . 17
⊢
(((abs‘𝑀)
∈ ℤ ∧ 𝑁
∈ ℤ) → ((abs‘𝑀) ∥ 𝑁 ↔ (abs‘𝑀) ∥ (abs‘𝑁))) |
| 44 | 25, 42, 43 | syl2an 289 |
. . . . . . . . . . . . . . . 16
⊢
(((abs‘𝑀)
∈ ℕ ∧ (𝑁
∈ ℤ ∧ 𝑁 ≠
0)) → ((abs‘𝑀)
∥ 𝑁 ↔
(abs‘𝑀) ∥
(abs‘𝑁))) |
| 45 | | nnsqcl 10718 |
. . . . . . . . . . . . . . . . . . 19
⊢
((abs‘𝑀)
∈ ℕ → ((abs‘𝑀)↑2) ∈ ℕ) |
| 46 | 45 | nnzd 9464 |
. . . . . . . . . . . . . . . . . 18
⊢
((abs‘𝑀)
∈ ℕ → ((abs‘𝑀)↑2) ∈ ℤ) |
| 47 | 10 | adantr 276 |
. . . . . . . . . . . . . . . . . 18
⊢ ((𝑁 ∈ ℤ ∧ 𝑁 ≠ 0) → (𝑁↑2) ∈
ℤ) |
| 48 | | dvdsabsb 11992 |
. . . . . . . . . . . . . . . . . 18
⊢
((((abs‘𝑀)↑2) ∈ ℤ ∧ (𝑁↑2) ∈ ℤ) →
(((abs‘𝑀)↑2)
∥ (𝑁↑2) ↔
((abs‘𝑀)↑2)
∥ (abs‘(𝑁↑2)))) |
| 49 | 46, 47, 48 | syl2an 289 |
. . . . . . . . . . . . . . . . 17
⊢
(((abs‘𝑀)
∈ ℕ ∧ (𝑁
∈ ℤ ∧ 𝑁 ≠
0)) → (((abs‘𝑀)↑2) ∥ (𝑁↑2) ↔ ((abs‘𝑀)↑2) ∥
(abs‘(𝑁↑2)))) |
| 50 | 6 | adantr 276 |
. . . . . . . . . . . . . . . . . . . 20
⊢ ((𝑁 ∈ ℤ ∧ 𝑁 ≠ 0) → 𝑁 ∈
ℂ) |
| 51 | | abssq 11263 |
. . . . . . . . . . . . . . . . . . . 20
⊢ (𝑁 ∈ ℂ →
((abs‘𝑁)↑2) =
(abs‘(𝑁↑2))) |
| 52 | 50, 51 | syl 14 |
. . . . . . . . . . . . . . . . . . 19
⊢ ((𝑁 ∈ ℤ ∧ 𝑁 ≠ 0) →
((abs‘𝑁)↑2) =
(abs‘(𝑁↑2))) |
| 53 | 52 | breq2d 4046 |
. . . . . . . . . . . . . . . . . 18
⊢ ((𝑁 ∈ ℤ ∧ 𝑁 ≠ 0) →
(((abs‘𝑀)↑2)
∥ ((abs‘𝑁)↑2) ↔ ((abs‘𝑀)↑2) ∥
(abs‘(𝑁↑2)))) |
| 54 | 53 | adantl 277 |
. . . . . . . . . . . . . . . . 17
⊢
(((abs‘𝑀)
∈ ℕ ∧ (𝑁
∈ ℤ ∧ 𝑁 ≠
0)) → (((abs‘𝑀)↑2) ∥ ((abs‘𝑁)↑2) ↔
((abs‘𝑀)↑2)
∥ (abs‘(𝑁↑2)))) |
| 55 | 49, 54 | bitr4d 191 |
. . . . . . . . . . . . . . . 16
⊢
(((abs‘𝑀)
∈ ℕ ∧ (𝑁
∈ ℤ ∧ 𝑁 ≠
0)) → (((abs‘𝑀)↑2) ∥ (𝑁↑2) ↔ ((abs‘𝑀)↑2) ∥
((abs‘𝑁)↑2))) |
| 56 | 41, 44, 55 | 3bitr4d 220 |
. . . . . . . . . . . . . . 15
⊢
(((abs‘𝑀)
∈ ℕ ∧ (𝑁
∈ ℤ ∧ 𝑁 ≠
0)) → ((abs‘𝑀)
∥ 𝑁 ↔
((abs‘𝑀)↑2)
∥ (𝑁↑2))) |
| 57 | 56 | anassrs 400 |
. . . . . . . . . . . . . 14
⊢
((((abs‘𝑀)
∈ ℕ ∧ 𝑁
∈ ℤ) ∧ 𝑁
≠ 0) → ((abs‘𝑀) ∥ 𝑁 ↔ ((abs‘𝑀)↑2) ∥ (𝑁↑2))) |
| 58 | 57 | expcom 116 |
. . . . . . . . . . . . 13
⊢ (𝑁 ≠ 0 →
(((abs‘𝑀) ∈
ℕ ∧ 𝑁 ∈
ℤ) → ((abs‘𝑀) ∥ 𝑁 ↔ ((abs‘𝑀)↑2) ∥ (𝑁↑2)))) |
| 59 | 38, 58 | sylbir 135 |
. . . . . . . . . . . 12
⊢ (¬
𝑁 = 0 →
(((abs‘𝑀) ∈
ℕ ∧ 𝑁 ∈
ℤ) → ((abs‘𝑀) ∥ 𝑁 ↔ ((abs‘𝑀)↑2) ∥ (𝑁↑2)))) |
| 60 | 37, 59 | jaoi 717 |
. . . . . . . . . . 11
⊢ ((𝑁 = 0 ∨ ¬ 𝑁 = 0) → (((abs‘𝑀) ∈ ℕ ∧ 𝑁 ∈ ℤ) →
((abs‘𝑀) ∥
𝑁 ↔ ((abs‘𝑀)↑2) ∥ (𝑁↑2)))) |
| 61 | 23, 24, 60 | 3syl 17 |
. . . . . . . . . 10
⊢ (𝑁 ∈ ℤ →
(((abs‘𝑀) ∈
ℕ ∧ 𝑁 ∈
ℤ) → ((abs‘𝑀) ∥ 𝑁 ↔ ((abs‘𝑀)↑2) ∥ (𝑁↑2)))) |
| 62 | 61 | anabsi7 581 |
. . . . . . . . 9
⊢
(((abs‘𝑀)
∈ ℕ ∧ 𝑁
∈ ℤ) → ((abs‘𝑀) ∥ 𝑁 ↔ ((abs‘𝑀)↑2) ∥ (𝑁↑2))) |
| 63 | 21, 62 | sylan 283 |
. . . . . . . 8
⊢ (((𝑀 ∈ ℤ ∧ 𝑀 ≠ 0) ∧ 𝑁 ∈ ℤ) → ((abs‘𝑀) ∥ 𝑁 ↔ ((abs‘𝑀)↑2) ∥ (𝑁↑2))) |
| 64 | | absdvdsb 11991 |
. . . . . . . . 9
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ 𝑁 ↔ (abs‘𝑀) ∥ 𝑁)) |
| 65 | 64 | adantlr 477 |
. . . . . . . 8
⊢ (((𝑀 ∈ ℤ ∧ 𝑀 ≠ 0) ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ 𝑁 ↔ (abs‘𝑀) ∥ 𝑁)) |
| 66 | | zsqcl 10719 |
. . . . . . . . . . 11
⊢ (𝑀 ∈ ℤ → (𝑀↑2) ∈
ℤ) |
| 67 | 66 | adantr 276 |
. . . . . . . . . 10
⊢ ((𝑀 ∈ ℤ ∧ 𝑀 ≠ 0) → (𝑀↑2) ∈
ℤ) |
| 68 | | absdvdsb 11991 |
. . . . . . . . . 10
⊢ (((𝑀↑2) ∈ ℤ ∧
(𝑁↑2) ∈ ℤ)
→ ((𝑀↑2) ∥
(𝑁↑2) ↔
(abs‘(𝑀↑2))
∥ (𝑁↑2))) |
| 69 | 67, 10, 68 | syl2an 289 |
. . . . . . . . 9
⊢ (((𝑀 ∈ ℤ ∧ 𝑀 ≠ 0) ∧ 𝑁 ∈ ℤ) → ((𝑀↑2) ∥ (𝑁↑2) ↔ (abs‘(𝑀↑2)) ∥ (𝑁↑2))) |
| 70 | | zcn 9348 |
. . . . . . . . . . . . . 14
⊢ (𝑀 ∈ ℤ → 𝑀 ∈
ℂ) |
| 71 | | abssq 11263 |
. . . . . . . . . . . . . 14
⊢ (𝑀 ∈ ℂ →
((abs‘𝑀)↑2) =
(abs‘(𝑀↑2))) |
| 72 | 70, 71 | syl 14 |
. . . . . . . . . . . . 13
⊢ (𝑀 ∈ ℤ →
((abs‘𝑀)↑2) =
(abs‘(𝑀↑2))) |
| 73 | 72 | eqcomd 2202 |
. . . . . . . . . . . 12
⊢ (𝑀 ∈ ℤ →
(abs‘(𝑀↑2)) =
((abs‘𝑀)↑2)) |
| 74 | 73 | adantr 276 |
. . . . . . . . . . 11
⊢ ((𝑀 ∈ ℤ ∧ 𝑀 ≠ 0) →
(abs‘(𝑀↑2)) =
((abs‘𝑀)↑2)) |
| 75 | 74 | breq1d 4044 |
. . . . . . . . . 10
⊢ ((𝑀 ∈ ℤ ∧ 𝑀 ≠ 0) →
((abs‘(𝑀↑2))
∥ (𝑁↑2) ↔
((abs‘𝑀)↑2)
∥ (𝑁↑2))) |
| 76 | 75 | adantr 276 |
. . . . . . . . 9
⊢ (((𝑀 ∈ ℤ ∧ 𝑀 ≠ 0) ∧ 𝑁 ∈ ℤ) → ((abs‘(𝑀↑2)) ∥ (𝑁↑2) ↔
((abs‘𝑀)↑2)
∥ (𝑁↑2))) |
| 77 | 69, 76 | bitrd 188 |
. . . . . . . 8
⊢ (((𝑀 ∈ ℤ ∧ 𝑀 ≠ 0) ∧ 𝑁 ∈ ℤ) → ((𝑀↑2) ∥ (𝑁↑2) ↔ ((abs‘𝑀)↑2) ∥ (𝑁↑2))) |
| 78 | 63, 65, 77 | 3bitr4d 220 |
. . . . . . 7
⊢ (((𝑀 ∈ ℤ ∧ 𝑀 ≠ 0) ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ 𝑁 ↔ (𝑀↑2) ∥ (𝑁↑2))) |
| 79 | 78 | an32s 568 |
. . . . . 6
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ 𝑀 ≠ 0) → (𝑀 ∥ 𝑁 ↔ (𝑀↑2) ∥ (𝑁↑2))) |
| 80 | 79 | expcom 116 |
. . . . 5
⊢ (𝑀 ≠ 0 → ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ 𝑁 ↔ (𝑀↑2) ∥ (𝑁↑2)))) |
| 81 | 20, 80 | sylbir 135 |
. . . 4
⊢ (¬
𝑀 = 0 → ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ 𝑁 ↔ (𝑀↑2) ∥ (𝑁↑2)))) |
| 82 | 19, 81 | jaoi 717 |
. . 3
⊢ ((𝑀 = 0 ∨ ¬ 𝑀 = 0) → ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ 𝑁 ↔ (𝑀↑2) ∥ (𝑁↑2)))) |
| 83 | 3, 4, 82 | 3syl 17 |
. 2
⊢ (𝑀 ∈ ℤ → ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ 𝑁 ↔ (𝑀↑2) ∥ (𝑁↑2)))) |
| 84 | 83 | anabsi5 579 |
1
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ 𝑁 ↔ (𝑀↑2) ∥ (𝑁↑2))) |