Proof of Theorem lcmcllem
Step | Hyp | Ref
| Expression |
1 | | lcmn0val 11998 |
. 2
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑀 lcm 𝑁) = inf({𝑛 ∈ ℕ ∣ (𝑀 ∥ 𝑛 ∧ 𝑁 ∥ 𝑛)}, ℝ, < )) |
2 | | 1zzd 9218 |
. . 3
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → 1 ∈
ℤ) |
3 | | nnuz 9501 |
. . . 4
⊢ ℕ =
(ℤ≥‘1) |
4 | | rabeq 2718 |
. . . 4
⊢ (ℕ
= (ℤ≥‘1) → {𝑛 ∈ ℕ ∣ (𝑀 ∥ 𝑛 ∧ 𝑁 ∥ 𝑛)} = {𝑛 ∈ (ℤ≥‘1)
∣ (𝑀 ∥ 𝑛 ∧ 𝑁 ∥ 𝑛)}) |
5 | 3, 4 | ax-mp 5 |
. . 3
⊢ {𝑛 ∈ ℕ ∣ (𝑀 ∥ 𝑛 ∧ 𝑁 ∥ 𝑛)} = {𝑛 ∈ (ℤ≥‘1)
∣ (𝑀 ∥ 𝑛 ∧ 𝑁 ∥ 𝑛)} |
6 | | simpll 519 |
. . . . . 6
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → 𝑀 ∈ ℤ) |
7 | | simplr 520 |
. . . . . 6
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → 𝑁 ∈ ℤ) |
8 | 6, 7 | zmulcld 9319 |
. . . . 5
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑀 · 𝑁) ∈ ℤ) |
9 | 6 | zcnd 9314 |
. . . . . . 7
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → 𝑀 ∈ ℂ) |
10 | 7 | zcnd 9314 |
. . . . . . 7
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → 𝑁 ∈ ℂ) |
11 | | ioran 742 |
. . . . . . . . . . . 12
⊢ (¬
(𝑀 = 0 ∨ 𝑁 = 0) ↔ (¬ 𝑀 = 0 ∧ ¬ 𝑁 = 0)) |
12 | 11 | biimpi 119 |
. . . . . . . . . . 11
⊢ (¬
(𝑀 = 0 ∨ 𝑁 = 0) → (¬ 𝑀 = 0 ∧ ¬ 𝑁 = 0)) |
13 | 12 | adantl 275 |
. . . . . . . . . 10
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (¬ 𝑀 = 0 ∧ ¬ 𝑁 = 0)) |
14 | 13 | simpld 111 |
. . . . . . . . 9
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → ¬ 𝑀 = 0) |
15 | 14 | neqned 2343 |
. . . . . . . 8
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → 𝑀 ≠ 0) |
16 | | 0zd 9203 |
. . . . . . . . 9
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → 0 ∈
ℤ) |
17 | | zapne 9265 |
. . . . . . . . 9
⊢ ((𝑀 ∈ ℤ ∧ 0 ∈
ℤ) → (𝑀 # 0
↔ 𝑀 ≠
0)) |
18 | 6, 16, 17 | syl2anc 409 |
. . . . . . . 8
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑀 # 0 ↔ 𝑀 ≠ 0)) |
19 | 15, 18 | mpbird 166 |
. . . . . . 7
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → 𝑀 # 0) |
20 | 13 | simprd 113 |
. . . . . . . . 9
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → ¬ 𝑁 = 0) |
21 | 20 | neqned 2343 |
. . . . . . . 8
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → 𝑁 ≠ 0) |
22 | | zapne 9265 |
. . . . . . . . 9
⊢ ((𝑁 ∈ ℤ ∧ 0 ∈
ℤ) → (𝑁 # 0
↔ 𝑁 ≠
0)) |
23 | 7, 16, 22 | syl2anc 409 |
. . . . . . . 8
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑁 # 0 ↔ 𝑁 ≠ 0)) |
24 | 21, 23 | mpbird 166 |
. . . . . . 7
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → 𝑁 # 0) |
25 | 9, 10, 19, 24 | mulap0d 8555 |
. . . . . 6
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑀 · 𝑁) # 0) |
26 | | zapne 9265 |
. . . . . . 7
⊢ (((𝑀 · 𝑁) ∈ ℤ ∧ 0 ∈ ℤ)
→ ((𝑀 · 𝑁) # 0 ↔ (𝑀 · 𝑁) ≠ 0)) |
27 | 8, 16, 26 | syl2anc 409 |
. . . . . 6
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → ((𝑀 · 𝑁) # 0 ↔ (𝑀 · 𝑁) ≠ 0)) |
28 | 25, 27 | mpbid 146 |
. . . . 5
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑀 · 𝑁) ≠ 0) |
29 | | nnabscl 11042 |
. . . . 5
⊢ (((𝑀 · 𝑁) ∈ ℤ ∧ (𝑀 · 𝑁) ≠ 0) → (abs‘(𝑀 · 𝑁)) ∈ ℕ) |
30 | 8, 28, 29 | syl2anc 409 |
. . . 4
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (abs‘(𝑀 · 𝑁)) ∈ ℕ) |
31 | | dvdsmul1 11753 |
. . . . . . 7
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → 𝑀 ∥ (𝑀 · 𝑁)) |
32 | | zmulcl 9244 |
. . . . . . . 8
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 · 𝑁) ∈ ℤ) |
33 | | dvdsabsb 11750 |
. . . . . . . 8
⊢ ((𝑀 ∈ ℤ ∧ (𝑀 · 𝑁) ∈ ℤ) → (𝑀 ∥ (𝑀 · 𝑁) ↔ 𝑀 ∥ (abs‘(𝑀 · 𝑁)))) |
34 | 32, 33 | syldan 280 |
. . . . . . 7
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ (𝑀 · 𝑁) ↔ 𝑀 ∥ (abs‘(𝑀 · 𝑁)))) |
35 | 31, 34 | mpbid 146 |
. . . . . 6
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → 𝑀 ∥ (abs‘(𝑀 · 𝑁))) |
36 | | dvdsmul2 11754 |
. . . . . . 7
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → 𝑁 ∥ (𝑀 · 𝑁)) |
37 | | dvdsabsb 11750 |
. . . . . . . . 9
⊢ ((𝑁 ∈ ℤ ∧ (𝑀 · 𝑁) ∈ ℤ) → (𝑁 ∥ (𝑀 · 𝑁) ↔ 𝑁 ∥ (abs‘(𝑀 · 𝑁)))) |
38 | 32, 37 | sylan2 284 |
. . . . . . . 8
⊢ ((𝑁 ∈ ℤ ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → (𝑁 ∥ (𝑀 · 𝑁) ↔ 𝑁 ∥ (abs‘(𝑀 · 𝑁)))) |
39 | 38 | anabss7 573 |
. . . . . . 7
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑁 ∥ (𝑀 · 𝑁) ↔ 𝑁 ∥ (abs‘(𝑀 · 𝑁)))) |
40 | 36, 39 | mpbid 146 |
. . . . . 6
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → 𝑁 ∥ (abs‘(𝑀 · 𝑁))) |
41 | 35, 40 | jca 304 |
. . . . 5
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ (abs‘(𝑀 · 𝑁)) ∧ 𝑁 ∥ (abs‘(𝑀 · 𝑁)))) |
42 | 41 | adantr 274 |
. . . 4
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑀 ∥ (abs‘(𝑀 · 𝑁)) ∧ 𝑁 ∥ (abs‘(𝑀 · 𝑁)))) |
43 | | breq2 3986 |
. . . . . 6
⊢ (𝑛 = (abs‘(𝑀 · 𝑁)) → (𝑀 ∥ 𝑛 ↔ 𝑀 ∥ (abs‘(𝑀 · 𝑁)))) |
44 | | breq2 3986 |
. . . . . 6
⊢ (𝑛 = (abs‘(𝑀 · 𝑁)) → (𝑁 ∥ 𝑛 ↔ 𝑁 ∥ (abs‘(𝑀 · 𝑁)))) |
45 | 43, 44 | anbi12d 465 |
. . . . 5
⊢ (𝑛 = (abs‘(𝑀 · 𝑁)) → ((𝑀 ∥ 𝑛 ∧ 𝑁 ∥ 𝑛) ↔ (𝑀 ∥ (abs‘(𝑀 · 𝑁)) ∧ 𝑁 ∥ (abs‘(𝑀 · 𝑁))))) |
46 | 45 | elrab 2882 |
. . . 4
⊢
((abs‘(𝑀
· 𝑁)) ∈ {𝑛 ∈ ℕ ∣ (𝑀 ∥ 𝑛 ∧ 𝑁 ∥ 𝑛)} ↔ ((abs‘(𝑀 · 𝑁)) ∈ ℕ ∧ (𝑀 ∥ (abs‘(𝑀 · 𝑁)) ∧ 𝑁 ∥ (abs‘(𝑀 · 𝑁))))) |
47 | 30, 42, 46 | sylanbrc 414 |
. . 3
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (abs‘(𝑀 · 𝑁)) ∈ {𝑛 ∈ ℕ ∣ (𝑀 ∥ 𝑛 ∧ 𝑁 ∥ 𝑛)}) |
48 | | simplll 523 |
. . . . 5
⊢ ((((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) ∧ 𝑛 ∈ (1...(abs‘(𝑀 · 𝑁)))) → 𝑀 ∈ ℤ) |
49 | | elfzelz 9960 |
. . . . . 6
⊢ (𝑛 ∈ (1...(abs‘(𝑀 · 𝑁))) → 𝑛 ∈ ℤ) |
50 | 49 | adantl 275 |
. . . . 5
⊢ ((((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) ∧ 𝑛 ∈ (1...(abs‘(𝑀 · 𝑁)))) → 𝑛 ∈ ℤ) |
51 | | zdvdsdc 11752 |
. . . . 5
⊢ ((𝑀 ∈ ℤ ∧ 𝑛 ∈ ℤ) →
DECID 𝑀
∥ 𝑛) |
52 | 48, 50, 51 | syl2anc 409 |
. . . 4
⊢ ((((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) ∧ 𝑛 ∈ (1...(abs‘(𝑀 · 𝑁)))) → DECID 𝑀 ∥ 𝑛) |
53 | | simpllr 524 |
. . . . 5
⊢ ((((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) ∧ 𝑛 ∈ (1...(abs‘(𝑀 · 𝑁)))) → 𝑁 ∈ ℤ) |
54 | | zdvdsdc 11752 |
. . . . 5
⊢ ((𝑁 ∈ ℤ ∧ 𝑛 ∈ ℤ) →
DECID 𝑁
∥ 𝑛) |
55 | 53, 50, 54 | syl2anc 409 |
. . . 4
⊢ ((((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) ∧ 𝑛 ∈ (1...(abs‘(𝑀 · 𝑁)))) → DECID 𝑁 ∥ 𝑛) |
56 | | dcan2 924 |
. . . 4
⊢
(DECID 𝑀 ∥ 𝑛 → (DECID 𝑁 ∥ 𝑛 → DECID (𝑀 ∥ 𝑛 ∧ 𝑁 ∥ 𝑛))) |
57 | 52, 55, 56 | sylc 62 |
. . 3
⊢ ((((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) ∧ 𝑛 ∈ (1...(abs‘(𝑀 · 𝑁)))) → DECID (𝑀 ∥ 𝑛 ∧ 𝑁 ∥ 𝑛)) |
58 | 2, 5, 47, 57 | infssuzcldc 11884 |
. 2
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → inf({𝑛 ∈ ℕ ∣ (𝑀 ∥ 𝑛 ∧ 𝑁 ∥ 𝑛)}, ℝ, < ) ∈ {𝑛 ∈ ℕ ∣ (𝑀 ∥ 𝑛 ∧ 𝑁 ∥ 𝑛)}) |
59 | 1, 58 | eqeltrd 2243 |
1
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑀 lcm 𝑁) ∈ {𝑛 ∈ ℕ ∣ (𝑀 ∥ 𝑛 ∧ 𝑁 ∥ 𝑛)}) |