Proof of Theorem lcmneg
Step | Hyp | Ref
| Expression |
1 | | lcm0val 11997 |
. . . . . . . 8
⊢ (𝑁 ∈ ℤ → (𝑁 lcm 0) = 0) |
2 | | znegcl 9222 |
. . . . . . . . 9
⊢ (𝑁 ∈ ℤ → -𝑁 ∈
ℤ) |
3 | | lcm0val 11997 |
. . . . . . . . 9
⊢ (-𝑁 ∈ ℤ → (-𝑁 lcm 0) = 0) |
4 | 2, 3 | syl 14 |
. . . . . . . 8
⊢ (𝑁 ∈ ℤ → (-𝑁 lcm 0) = 0) |
5 | 1, 4 | eqtr4d 2201 |
. . . . . . 7
⊢ (𝑁 ∈ ℤ → (𝑁 lcm 0) = (-𝑁 lcm 0)) |
6 | 5 | ad2antlr 481 |
. . . . . 6
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ 𝑀 = 0) → (𝑁 lcm 0) = (-𝑁 lcm 0)) |
7 | | oveq2 5850 |
. . . . . . . 8
⊢ (𝑀 = 0 → (𝑁 lcm 𝑀) = (𝑁 lcm 0)) |
8 | | oveq2 5850 |
. . . . . . . 8
⊢ (𝑀 = 0 → (-𝑁 lcm 𝑀) = (-𝑁 lcm 0)) |
9 | 7, 8 | eqeq12d 2180 |
. . . . . . 7
⊢ (𝑀 = 0 → ((𝑁 lcm 𝑀) = (-𝑁 lcm 𝑀) ↔ (𝑁 lcm 0) = (-𝑁 lcm 0))) |
10 | 9 | adantl 275 |
. . . . . 6
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ 𝑀 = 0) → ((𝑁 lcm 𝑀) = (-𝑁 lcm 𝑀) ↔ (𝑁 lcm 0) = (-𝑁 lcm 0))) |
11 | 6, 10 | mpbird 166 |
. . . . 5
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ 𝑀 = 0) → (𝑁 lcm 𝑀) = (-𝑁 lcm 𝑀)) |
12 | | lcmcom 11996 |
. . . . . . 7
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 lcm 𝑁) = (𝑁 lcm 𝑀)) |
13 | | lcmcom 11996 |
. . . . . . . 8
⊢ ((𝑀 ∈ ℤ ∧ -𝑁 ∈ ℤ) → (𝑀 lcm -𝑁) = (-𝑁 lcm 𝑀)) |
14 | 2, 13 | sylan2 284 |
. . . . . . 7
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 lcm -𝑁) = (-𝑁 lcm 𝑀)) |
15 | 12, 14 | eqeq12d 2180 |
. . . . . 6
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝑀 lcm 𝑁) = (𝑀 lcm -𝑁) ↔ (𝑁 lcm 𝑀) = (-𝑁 lcm 𝑀))) |
16 | 15 | adantr 274 |
. . . . 5
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ 𝑀 = 0) → ((𝑀 lcm 𝑁) = (𝑀 lcm -𝑁) ↔ (𝑁 lcm 𝑀) = (-𝑁 lcm 𝑀))) |
17 | 11, 16 | mpbird 166 |
. . . 4
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ 𝑀 = 0) → (𝑀 lcm 𝑁) = (𝑀 lcm -𝑁)) |
18 | | neg0 8144 |
. . . . . . . 8
⊢ -0 =
0 |
19 | 18 | oveq2i 5853 |
. . . . . . 7
⊢ (𝑀 lcm -0) = (𝑀 lcm 0) |
20 | 19 | eqcomi 2169 |
. . . . . 6
⊢ (𝑀 lcm 0) = (𝑀 lcm -0) |
21 | | oveq2 5850 |
. . . . . 6
⊢ (𝑁 = 0 → (𝑀 lcm 𝑁) = (𝑀 lcm 0)) |
22 | | negeq 8091 |
. . . . . . 7
⊢ (𝑁 = 0 → -𝑁 = -0) |
23 | 22 | oveq2d 5858 |
. . . . . 6
⊢ (𝑁 = 0 → (𝑀 lcm -𝑁) = (𝑀 lcm -0)) |
24 | 20, 21, 23 | 3eqtr4a 2225 |
. . . . 5
⊢ (𝑁 = 0 → (𝑀 lcm 𝑁) = (𝑀 lcm -𝑁)) |
25 | 24 | adantl 275 |
. . . 4
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ 𝑁 = 0) → (𝑀 lcm 𝑁) = (𝑀 lcm -𝑁)) |
26 | 17, 25 | jaodan 787 |
. . 3
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝑀 = 0 ∨ 𝑁 = 0)) → (𝑀 lcm 𝑁) = (𝑀 lcm -𝑁)) |
27 | | dvdslcm 12001 |
. . . . . . . 8
⊢ ((𝑀 ∈ ℤ ∧ -𝑁 ∈ ℤ) → (𝑀 ∥ (𝑀 lcm -𝑁) ∧ -𝑁 ∥ (𝑀 lcm -𝑁))) |
28 | 2, 27 | sylan2 284 |
. . . . . . 7
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ (𝑀 lcm -𝑁) ∧ -𝑁 ∥ (𝑀 lcm -𝑁))) |
29 | | simpr 109 |
. . . . . . . . 9
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → 𝑁 ∈
ℤ) |
30 | | lcmcl 12004 |
. . . . . . . . . . 11
⊢ ((𝑀 ∈ ℤ ∧ -𝑁 ∈ ℤ) → (𝑀 lcm -𝑁) ∈
ℕ0) |
31 | 2, 30 | sylan2 284 |
. . . . . . . . . 10
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 lcm -𝑁) ∈
ℕ0) |
32 | 31 | nn0zd 9311 |
. . . . . . . . 9
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 lcm -𝑁) ∈ ℤ) |
33 | | negdvdsb 11747 |
. . . . . . . . 9
⊢ ((𝑁 ∈ ℤ ∧ (𝑀 lcm -𝑁) ∈ ℤ) → (𝑁 ∥ (𝑀 lcm -𝑁) ↔ -𝑁 ∥ (𝑀 lcm -𝑁))) |
34 | 29, 32, 33 | syl2anc 409 |
. . . . . . . 8
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑁 ∥ (𝑀 lcm -𝑁) ↔ -𝑁 ∥ (𝑀 lcm -𝑁))) |
35 | 34 | anbi2d 460 |
. . . . . . 7
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝑀 ∥ (𝑀 lcm -𝑁) ∧ 𝑁 ∥ (𝑀 lcm -𝑁)) ↔ (𝑀 ∥ (𝑀 lcm -𝑁) ∧ -𝑁 ∥ (𝑀 lcm -𝑁)))) |
36 | 28, 35 | mpbird 166 |
. . . . . 6
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ (𝑀 lcm -𝑁) ∧ 𝑁 ∥ (𝑀 lcm -𝑁))) |
37 | 36 | adantr 274 |
. . . . 5
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑀 ∥ (𝑀 lcm -𝑁) ∧ 𝑁 ∥ (𝑀 lcm -𝑁))) |
38 | | zcn 9196 |
. . . . . . . . . . . . 13
⊢ (𝑁 ∈ ℤ → 𝑁 ∈
ℂ) |
39 | 38 | negeq0d 8201 |
. . . . . . . . . . . 12
⊢ (𝑁 ∈ ℤ → (𝑁 = 0 ↔ -𝑁 = 0)) |
40 | 39 | orbi2d 780 |
. . . . . . . . . . 11
⊢ (𝑁 ∈ ℤ → ((𝑀 = 0 ∨ 𝑁 = 0) ↔ (𝑀 = 0 ∨ -𝑁 = 0))) |
41 | 40 | notbid 657 |
. . . . . . . . . 10
⊢ (𝑁 ∈ ℤ → (¬
(𝑀 = 0 ∨ 𝑁 = 0) ↔ ¬ (𝑀 = 0 ∨ -𝑁 = 0))) |
42 | 41 | biimpa 294 |
. . . . . . . . 9
⊢ ((𝑁 ∈ ℤ ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → ¬ (𝑀 = 0 ∨ -𝑁 = 0)) |
43 | 42 | adantll 468 |
. . . . . . . 8
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → ¬ (𝑀 = 0 ∨ -𝑁 = 0)) |
44 | | lcmn0cl 12000 |
. . . . . . . . 9
⊢ (((𝑀 ∈ ℤ ∧ -𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ -𝑁 = 0)) → (𝑀 lcm -𝑁) ∈ ℕ) |
45 | 2, 44 | sylanl2 401 |
. . . . . . . 8
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ -𝑁 = 0)) → (𝑀 lcm -𝑁) ∈ ℕ) |
46 | 43, 45 | syldan 280 |
. . . . . . 7
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑀 lcm -𝑁) ∈ ℕ) |
47 | | simpl 108 |
. . . . . . 7
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) |
48 | | 3anass 972 |
. . . . . . 7
⊢ (((𝑀 lcm -𝑁) ∈ ℕ ∧ 𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ↔ ((𝑀 lcm -𝑁) ∈ ℕ ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ))) |
49 | 46, 47, 48 | sylanbrc 414 |
. . . . . 6
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → ((𝑀 lcm -𝑁) ∈ ℕ ∧ 𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) |
50 | | simpr 109 |
. . . . . 6
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → ¬ (𝑀 = 0 ∨ 𝑁 = 0)) |
51 | | lcmledvds 12002 |
. . . . . 6
⊢ ((((𝑀 lcm -𝑁) ∈ ℕ ∧ 𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬ (𝑀 = 0 ∨ 𝑁 = 0)) → ((𝑀 ∥ (𝑀 lcm -𝑁) ∧ 𝑁 ∥ (𝑀 lcm -𝑁)) → (𝑀 lcm 𝑁) ≤ (𝑀 lcm -𝑁))) |
52 | 49, 50, 51 | syl2anc 409 |
. . . . 5
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → ((𝑀 ∥ (𝑀 lcm -𝑁) ∧ 𝑁 ∥ (𝑀 lcm -𝑁)) → (𝑀 lcm 𝑁) ≤ (𝑀 lcm -𝑁))) |
53 | 37, 52 | mpd 13 |
. . . 4
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑀 lcm 𝑁) ≤ (𝑀 lcm -𝑁)) |
54 | | dvdslcm 12001 |
. . . . . 6
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ (𝑀 lcm 𝑁) ∧ 𝑁 ∥ (𝑀 lcm 𝑁))) |
55 | 54 | adantr 274 |
. . . . 5
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑀 ∥ (𝑀 lcm 𝑁) ∧ 𝑁 ∥ (𝑀 lcm 𝑁))) |
56 | | simplr 520 |
. . . . . . . 8
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → 𝑁 ∈ ℤ) |
57 | | lcmn0cl 12000 |
. . . . . . . . 9
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑀 lcm 𝑁) ∈ ℕ) |
58 | 57 | nnzd 9312 |
. . . . . . . 8
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑀 lcm 𝑁) ∈ ℤ) |
59 | | negdvdsb 11747 |
. . . . . . . 8
⊢ ((𝑁 ∈ ℤ ∧ (𝑀 lcm 𝑁) ∈ ℤ) → (𝑁 ∥ (𝑀 lcm 𝑁) ↔ -𝑁 ∥ (𝑀 lcm 𝑁))) |
60 | 56, 58, 59 | syl2anc 409 |
. . . . . . 7
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑁 ∥ (𝑀 lcm 𝑁) ↔ -𝑁 ∥ (𝑀 lcm 𝑁))) |
61 | 60 | anbi2d 460 |
. . . . . 6
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → ((𝑀 ∥ (𝑀 lcm 𝑁) ∧ 𝑁 ∥ (𝑀 lcm 𝑁)) ↔ (𝑀 ∥ (𝑀 lcm 𝑁) ∧ -𝑁 ∥ (𝑀 lcm 𝑁)))) |
62 | | lcmledvds 12002 |
. . . . . . . . . 10
⊢ ((((𝑀 lcm 𝑁) ∈ ℕ ∧ 𝑀 ∈ ℤ ∧ -𝑁 ∈ ℤ) ∧ ¬ (𝑀 = 0 ∨ -𝑁 = 0)) → ((𝑀 ∥ (𝑀 lcm 𝑁) ∧ -𝑁 ∥ (𝑀 lcm 𝑁)) → (𝑀 lcm -𝑁) ≤ (𝑀 lcm 𝑁))) |
63 | 62 | ex 114 |
. . . . . . . . 9
⊢ (((𝑀 lcm 𝑁) ∈ ℕ ∧ 𝑀 ∈ ℤ ∧ -𝑁 ∈ ℤ) → (¬ (𝑀 = 0 ∨ -𝑁 = 0) → ((𝑀 ∥ (𝑀 lcm 𝑁) ∧ -𝑁 ∥ (𝑀 lcm 𝑁)) → (𝑀 lcm -𝑁) ≤ (𝑀 lcm 𝑁)))) |
64 | 2, 63 | syl3an3 1263 |
. . . . . . . 8
⊢ (((𝑀 lcm 𝑁) ∈ ℕ ∧ 𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (¬ (𝑀 = 0 ∨ -𝑁 = 0) → ((𝑀 ∥ (𝑀 lcm 𝑁) ∧ -𝑁 ∥ (𝑀 lcm 𝑁)) → (𝑀 lcm -𝑁) ≤ (𝑀 lcm 𝑁)))) |
65 | 64 | 3expib 1196 |
. . . . . . 7
⊢ ((𝑀 lcm 𝑁) ∈ ℕ → ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (¬ (𝑀 = 0 ∨ -𝑁 = 0) → ((𝑀 ∥ (𝑀 lcm 𝑁) ∧ -𝑁 ∥ (𝑀 lcm 𝑁)) → (𝑀 lcm -𝑁) ≤ (𝑀 lcm 𝑁))))) |
66 | 57, 47, 43, 65 | syl3c 63 |
. . . . . 6
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → ((𝑀 ∥ (𝑀 lcm 𝑁) ∧ -𝑁 ∥ (𝑀 lcm 𝑁)) → (𝑀 lcm -𝑁) ≤ (𝑀 lcm 𝑁))) |
67 | 61, 66 | sylbid 149 |
. . . . 5
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → ((𝑀 ∥ (𝑀 lcm 𝑁) ∧ 𝑁 ∥ (𝑀 lcm 𝑁)) → (𝑀 lcm -𝑁) ≤ (𝑀 lcm 𝑁))) |
68 | 55, 67 | mpd 13 |
. . . 4
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑀 lcm -𝑁) ≤ (𝑀 lcm 𝑁)) |
69 | | lcmcl 12004 |
. . . . . . 7
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 lcm 𝑁) ∈
ℕ0) |
70 | 69 | nn0red 9168 |
. . . . . 6
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 lcm 𝑁) ∈ ℝ) |
71 | 30 | nn0red 9168 |
. . . . . . 7
⊢ ((𝑀 ∈ ℤ ∧ -𝑁 ∈ ℤ) → (𝑀 lcm -𝑁) ∈ ℝ) |
72 | 2, 71 | sylan2 284 |
. . . . . 6
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 lcm -𝑁) ∈ ℝ) |
73 | 70, 72 | letri3d 8014 |
. . . . 5
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝑀 lcm 𝑁) = (𝑀 lcm -𝑁) ↔ ((𝑀 lcm 𝑁) ≤ (𝑀 lcm -𝑁) ∧ (𝑀 lcm -𝑁) ≤ (𝑀 lcm 𝑁)))) |
74 | 73 | adantr 274 |
. . . 4
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → ((𝑀 lcm 𝑁) = (𝑀 lcm -𝑁) ↔ ((𝑀 lcm 𝑁) ≤ (𝑀 lcm -𝑁) ∧ (𝑀 lcm -𝑁) ≤ (𝑀 lcm 𝑁)))) |
75 | 53, 68, 74 | mpbir2and 934 |
. . 3
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬
(𝑀 = 0 ∨ 𝑁 = 0)) → (𝑀 lcm 𝑁) = (𝑀 lcm -𝑁)) |
76 | | lcmmndc 11994 |
. . . 4
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) →
DECID (𝑀 = 0
∨ 𝑁 =
0)) |
77 | | exmiddc 826 |
. . . 4
⊢
(DECID (𝑀 = 0 ∨ 𝑁 = 0) → ((𝑀 = 0 ∨ 𝑁 = 0) ∨ ¬ (𝑀 = 0 ∨ 𝑁 = 0))) |
78 | 76, 77 | syl 14 |
. . 3
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝑀 = 0 ∨ 𝑁 = 0) ∨ ¬ (𝑀 = 0 ∨ 𝑁 = 0))) |
79 | 26, 75, 78 | mpjaodan 788 |
. 2
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 lcm 𝑁) = (𝑀 lcm -𝑁)) |
80 | 79 | eqcomd 2171 |
1
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 lcm -𝑁) = (𝑀 lcm 𝑁)) |