lcmgcdeq - Metamath Proof Explorer

	Metamath Proof Explorer		< Previous Next > Nearby theorems
Mirrors > Home > MPE Home > Th. List > lcmgcdeq		Structured version Visualization version GIF version

Theorem lcmgcdeq 15163

Description: Two integers' absolute values are equal iff their least common multiple and greatest common divisor are equal. (Contributed by Steve Rodriguez, 20-Jan-2020.)

**Assertion**
Ref	Expression
lcmgcdeq	⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝑀 lcm 𝑁) = (𝑀 gcd 𝑁) ↔ (abs‘𝑀) = (abs‘𝑁)))

**Proof of Theorem lcmgcdeq**
Step	Hyp	Ref	Expression
1		dvdslcm 15149	. . . . . . 7 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ (𝑀 lcm 𝑁) ∧ 𝑁 ∥ (𝑀 lcm 𝑁)))
2	1	simpld 474	. . . . . 6 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → 𝑀 ∥ (𝑀 lcm 𝑁))
3	2	adantr 480	. . . . 5 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝑀 lcm 𝑁) = (𝑀 gcd 𝑁)) → 𝑀 ∥ (𝑀 lcm 𝑁))
4		gcddvds 15063	. . . . . . . 8 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝑀 gcd 𝑁) ∥ 𝑀 ∧ (𝑀 gcd 𝑁) ∥ 𝑁))
5	4	simprd 478	. . . . . . 7 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 gcd 𝑁) ∥ 𝑁)
6		breq1 4586	. . . . . . 7 ⊢ ((𝑀 lcm 𝑁) = (𝑀 gcd 𝑁) → ((𝑀 lcm 𝑁) ∥ 𝑁 ↔ (𝑀 gcd 𝑁) ∥ 𝑁))
7	5, 6	syl5ibrcom 236	. . . . . 6 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝑀 lcm 𝑁) = (𝑀 gcd 𝑁) → (𝑀 lcm 𝑁) ∥ 𝑁))
8	7	imp 444	. . . . 5 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝑀 lcm 𝑁) = (𝑀 gcd 𝑁)) → (𝑀 lcm 𝑁) ∥ 𝑁)
9		lcmcl 15152	. . . . . . . . . . 11 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 lcm 𝑁) ∈ ℕ₀)
10	9	nn0zd 11356	. . . . . . . . . 10 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 lcm 𝑁) ∈ ℤ)
11		dvdstr 14856	. . . . . . . . . 10 ⊢ ((𝑀 ∈ ℤ ∧ (𝑀 lcm 𝑁) ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝑀 ∥ (𝑀 lcm 𝑁) ∧ (𝑀 lcm 𝑁) ∥ 𝑁) → 𝑀 ∥ 𝑁))
12	10, 11	syl3an2 1352	. . . . . . . . 9 ⊢ ((𝑀 ∈ ℤ ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ 𝑁 ∈ ℤ) → ((𝑀 ∥ (𝑀 lcm 𝑁) ∧ (𝑀 lcm 𝑁) ∥ 𝑁) → 𝑀 ∥ 𝑁))
13	12	3com12 1261	. . . . . . . 8 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ 𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝑀 ∥ (𝑀 lcm 𝑁) ∧ (𝑀 lcm 𝑁) ∥ 𝑁) → 𝑀 ∥ 𝑁))
14	13	3expb 1258	. . . . . . 7 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → ((𝑀 ∥ (𝑀 lcm 𝑁) ∧ (𝑀 lcm 𝑁) ∥ 𝑁) → 𝑀 ∥ 𝑁))
15	14	anidms 675	. . . . . 6 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝑀 ∥ (𝑀 lcm 𝑁) ∧ (𝑀 lcm 𝑁) ∥ 𝑁) → 𝑀 ∥ 𝑁))
16	15	adantr 480	. . . . 5 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝑀 lcm 𝑁) = (𝑀 gcd 𝑁)) → ((𝑀 ∥ (𝑀 lcm 𝑁) ∧ (𝑀 lcm 𝑁) ∥ 𝑁) → 𝑀 ∥ 𝑁))
17	3, 8, 16	mp2and 711	. . . 4 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝑀 lcm 𝑁) = (𝑀 gcd 𝑁)) → 𝑀 ∥ 𝑁)
18		absdvdsb 14838	. . . . . 6 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ 𝑁 ↔ (abs‘𝑀) ∥ 𝑁))
19		zabscl 13901	. . . . . . 7 ⊢ (𝑀 ∈ ℤ → (abs‘𝑀) ∈ ℤ)
20		dvdsabsb 14839	. . . . . . 7 ⊢ (((abs‘𝑀) ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((abs‘𝑀) ∥ 𝑁 ↔ (abs‘𝑀) ∥ (abs‘𝑁)))
21	19, 20	sylan 487	. . . . . 6 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((abs‘𝑀) ∥ 𝑁 ↔ (abs‘𝑀) ∥ (abs‘𝑁)))
22	18, 21	bitrd 267	. . . . 5 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ 𝑁 ↔ (abs‘𝑀) ∥ (abs‘𝑁)))
23	22	adantr 480	. . . 4 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝑀 lcm 𝑁) = (𝑀 gcd 𝑁)) → (𝑀 ∥ 𝑁 ↔ (abs‘𝑀) ∥ (abs‘𝑁)))
24	17, 23	mpbid 221	. . 3 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝑀 lcm 𝑁) = (𝑀 gcd 𝑁)) → (abs‘𝑀) ∥ (abs‘𝑁))
25	1	simprd 478	. . . . . 6 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → 𝑁 ∥ (𝑀 lcm 𝑁))
26	25	adantr 480	. . . . 5 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝑀 lcm 𝑁) = (𝑀 gcd 𝑁)) → 𝑁 ∥ (𝑀 lcm 𝑁))
27	4	simpld 474	. . . . . . 7 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 gcd 𝑁) ∥ 𝑀)
28		breq1 4586	. . . . . . 7 ⊢ ((𝑀 lcm 𝑁) = (𝑀 gcd 𝑁) → ((𝑀 lcm 𝑁) ∥ 𝑀 ↔ (𝑀 gcd 𝑁) ∥ 𝑀))
29	27, 28	syl5ibrcom 236	. . . . . 6 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝑀 lcm 𝑁) = (𝑀 gcd 𝑁) → (𝑀 lcm 𝑁) ∥ 𝑀))
30	29	imp 444	. . . . 5 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝑀 lcm 𝑁) = (𝑀 gcd 𝑁)) → (𝑀 lcm 𝑁) ∥ 𝑀)
31		dvdstr 14856	. . . . . . . . . 10 ⊢ ((𝑁 ∈ ℤ ∧ (𝑀 lcm 𝑁) ∈ ℤ ∧ 𝑀 ∈ ℤ) → ((𝑁 ∥ (𝑀 lcm 𝑁) ∧ (𝑀 lcm 𝑁) ∥ 𝑀) → 𝑁 ∥ 𝑀))
32	10, 31	syl3an2 1352	. . . . . . . . 9 ⊢ ((𝑁 ∈ ℤ ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ 𝑀 ∈ ℤ) → ((𝑁 ∥ (𝑀 lcm 𝑁) ∧ (𝑀 lcm 𝑁) ∥ 𝑀) → 𝑁 ∥ 𝑀))
33	32	3coml 1264	. . . . . . . 8 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ 𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝑁 ∥ (𝑀 lcm 𝑁) ∧ (𝑀 lcm 𝑁) ∥ 𝑀) → 𝑁 ∥ 𝑀))
34	33	3expb 1258	. . . . . . 7 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → ((𝑁 ∥ (𝑀 lcm 𝑁) ∧ (𝑀 lcm 𝑁) ∥ 𝑀) → 𝑁 ∥ 𝑀))
35	34	anidms 675	. . . . . 6 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝑁 ∥ (𝑀 lcm 𝑁) ∧ (𝑀 lcm 𝑁) ∥ 𝑀) → 𝑁 ∥ 𝑀))
36	35	adantr 480	. . . . 5 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝑀 lcm 𝑁) = (𝑀 gcd 𝑁)) → ((𝑁 ∥ (𝑀 lcm 𝑁) ∧ (𝑀 lcm 𝑁) ∥ 𝑀) → 𝑁 ∥ 𝑀))
37	26, 30, 36	mp2and 711	. . . 4 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝑀 lcm 𝑁) = (𝑀 gcd 𝑁)) → 𝑁 ∥ 𝑀)
38		absdvdsb 14838	. . . . . . 7 ⊢ ((𝑁 ∈ ℤ ∧ 𝑀 ∈ ℤ) → (𝑁 ∥ 𝑀 ↔ (abs‘𝑁) ∥ 𝑀))
39		zabscl 13901	. . . . . . . 8 ⊢ (𝑁 ∈ ℤ → (abs‘𝑁) ∈ ℤ)
40		dvdsabsb 14839	. . . . . . . 8 ⊢ (((abs‘𝑁) ∈ ℤ ∧ 𝑀 ∈ ℤ) → ((abs‘𝑁) ∥ 𝑀 ↔ (abs‘𝑁) ∥ (abs‘𝑀)))
41	39, 40	sylan 487	. . . . . . 7 ⊢ ((𝑁 ∈ ℤ ∧ 𝑀 ∈ ℤ) → ((abs‘𝑁) ∥ 𝑀 ↔ (abs‘𝑁) ∥ (abs‘𝑀)))
42	38, 41	bitrd 267	. . . . . 6 ⊢ ((𝑁 ∈ ℤ ∧ 𝑀 ∈ ℤ) → (𝑁 ∥ 𝑀 ↔ (abs‘𝑁) ∥ (abs‘𝑀)))
43	42	ancoms 468	. . . . 5 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑁 ∥ 𝑀 ↔ (abs‘𝑁) ∥ (abs‘𝑀)))
44	43	adantr 480	. . . 4 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝑀 lcm 𝑁) = (𝑀 gcd 𝑁)) → (𝑁 ∥ 𝑀 ↔ (abs‘𝑁) ∥ (abs‘𝑀)))
45	37, 44	mpbid 221	. . 3 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝑀 lcm 𝑁) = (𝑀 gcd 𝑁)) → (abs‘𝑁) ∥ (abs‘𝑀))
46		nn0abscl 13900	. . . . . . 7 ⊢ (𝑀 ∈ ℤ → (abs‘𝑀) ∈ ℕ₀)
47		nn0abscl 13900	. . . . . . 7 ⊢ (𝑁 ∈ ℤ → (abs‘𝑁) ∈ ℕ₀)
48	46, 47	anim12i 588	. . . . . 6 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((abs‘𝑀) ∈ ℕ₀ ∧ (abs‘𝑁) ∈ ℕ₀))
49		dvdseq 14874	. . . . . 6 ⊢ ((((abs‘𝑀) ∈ ℕ₀ ∧ (abs‘𝑁) ∈ ℕ₀) ∧ ((abs‘𝑀) ∥ (abs‘𝑁) ∧ (abs‘𝑁) ∥ (abs‘𝑀))) → (abs‘𝑀) = (abs‘𝑁))
50	48, 49	sylan 487	. . . . 5 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ((abs‘𝑀) ∥ (abs‘𝑁) ∧ (abs‘𝑁) ∥ (abs‘𝑀))) → (abs‘𝑀) = (abs‘𝑁))
51	50	ex 449	. . . 4 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (((abs‘𝑀) ∥ (abs‘𝑁) ∧ (abs‘𝑁) ∥ (abs‘𝑀)) → (abs‘𝑀) = (abs‘𝑁)))
52	51	adantr 480	. . 3 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝑀 lcm 𝑁) = (𝑀 gcd 𝑁)) → (((abs‘𝑀) ∥ (abs‘𝑁) ∧ (abs‘𝑁) ∥ (abs‘𝑀)) → (abs‘𝑀) = (abs‘𝑁)))
53	24, 45, 52	mp2and 711	. 2 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝑀 lcm 𝑁) = (𝑀 gcd 𝑁)) → (abs‘𝑀) = (abs‘𝑁))
54		lcmid 15160	. . . . . . . 8 ⊢ ((abs‘𝑀) ∈ ℤ → ((abs‘𝑀) lcm (abs‘𝑀)) = (abs‘(abs‘𝑀)))
55	19, 54	syl 17	. . . . . . 7 ⊢ (𝑀 ∈ ℤ → ((abs‘𝑀) lcm (abs‘𝑀)) = (abs‘(abs‘𝑀)))
56		gcdid 15086	. . . . . . . 8 ⊢ ((abs‘𝑀) ∈ ℤ → ((abs‘𝑀) gcd (abs‘𝑀)) = (abs‘(abs‘𝑀)))
57	19, 56	syl 17	. . . . . . 7 ⊢ (𝑀 ∈ ℤ → ((abs‘𝑀) gcd (abs‘𝑀)) = (abs‘(abs‘𝑀)))
58	55, 57	eqtr4d 2647	. . . . . 6 ⊢ (𝑀 ∈ ℤ → ((abs‘𝑀) lcm (abs‘𝑀)) = ((abs‘𝑀) gcd (abs‘𝑀)))
59		oveq2 6557	. . . . . . 7 ⊢ ((abs‘𝑀) = (abs‘𝑁) → ((abs‘𝑀) lcm (abs‘𝑀)) = ((abs‘𝑀) lcm (abs‘𝑁)))
60		oveq2 6557	. . . . . . 7 ⊢ ((abs‘𝑀) = (abs‘𝑁) → ((abs‘𝑀) gcd (abs‘𝑀)) = ((abs‘𝑀) gcd (abs‘𝑁)))
61	59, 60	eqeq12d 2625	. . . . . 6 ⊢ ((abs‘𝑀) = (abs‘𝑁) → (((abs‘𝑀) lcm (abs‘𝑀)) = ((abs‘𝑀) gcd (abs‘𝑀)) ↔ ((abs‘𝑀) lcm (abs‘𝑁)) = ((abs‘𝑀) gcd (abs‘𝑁))))
62	58, 61	syl5ibcom 234	. . . . 5 ⊢ (𝑀 ∈ ℤ → ((abs‘𝑀) = (abs‘𝑁) → ((abs‘𝑀) lcm (abs‘𝑁)) = ((abs‘𝑀) gcd (abs‘𝑁))))
63	62	imp 444	. . . 4 ⊢ ((𝑀 ∈ ℤ ∧ (abs‘𝑀) = (abs‘𝑁)) → ((abs‘𝑀) lcm (abs‘𝑁)) = ((abs‘𝑀) gcd (abs‘𝑁)))
64	63	adantlr 747	. . 3 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (abs‘𝑀) = (abs‘𝑁)) → ((abs‘𝑀) lcm (abs‘𝑁)) = ((abs‘𝑀) gcd (abs‘𝑁)))
65		lcmabs 15156	. . . . 5 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((abs‘𝑀) lcm (abs‘𝑁)) = (𝑀 lcm 𝑁))
66		gcdabs 15088	. . . . 5 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((abs‘𝑀) gcd (abs‘𝑁)) = (𝑀 gcd 𝑁))
67	65, 66	eqeq12d 2625	. . . 4 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (((abs‘𝑀) lcm (abs‘𝑁)) = ((abs‘𝑀) gcd (abs‘𝑁)) ↔ (𝑀 lcm 𝑁) = (𝑀 gcd 𝑁)))
68	67	adantr 480	. . 3 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (abs‘𝑀) = (abs‘𝑁)) → (((abs‘𝑀) lcm (abs‘𝑁)) = ((abs‘𝑀) gcd (abs‘𝑁)) ↔ (𝑀 lcm 𝑁) = (𝑀 gcd 𝑁)))
69	64, 68	mpbid 221	. 2 ⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (abs‘𝑀) = (abs‘𝑁)) → (𝑀 lcm 𝑁) = (𝑀 gcd 𝑁))
70	53, 69	impbida 873	1 ⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝑀 lcm 𝑁) = (𝑀 gcd 𝑁) ↔ (abs‘𝑀) = (abs‘𝑁)))

Colors of variables: wff setvar class

Syntax hints: → wi 4 ↔ wb 195 ∧ wa 383 = wceq 1475 ∈ wcel 1977 class class class wbr 4583 ‘cfv 5804 (class class class)co 6549 ℕ₀cn0 11169 ℤcz 11254 abscabs 13822 ∥ cdvds 14821 gcd cgcd 15054 lcm clcm 15139

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1713 ax-4 1728 ax-5 1827 ax-6 1875 ax-7 1922 ax-8 1979 ax-9 1986 ax-10 2006 ax-11 2021 ax-12 2034 ax-13 2234 ax-ext 2590 ax-sep 4709 ax-nul 4717 ax-pow 4769 ax-pr 4833 ax-un 6847 ax-cnex 9871 ax-resscn 9872 ax-1cn 9873 ax-icn 9874 ax-addcl 9875 ax-addrcl 9876 ax-mulcl 9877 ax-mulrcl 9878 ax-mulcom 9879 ax-addass 9880 ax-mulass 9881 ax-distr 9882 ax-i2m1 9883 ax-1ne0 9884 ax-1rid 9885 ax-rnegex 9886 ax-rrecex 9887 ax-cnre 9888 ax-pre-lttri 9889 ax-pre-lttrn 9890 ax-pre-ltadd 9891 ax-pre-mulgt0 9892 ax-pre-sup 9893

This theorem depends on definitions: df-bi 196 df-or 384 df-an 385 df-3or 1032 df-3an 1033 df-tru 1478 df-ex 1696 df-nf 1701 df-sb 1868 df-eu 2462 df-mo 2463 df-clab 2597 df-cleq 2603 df-clel 2606 df-nfc 2740 df-ne 2782 df-nel 2783 df-ral 2901 df-rex 2902 df-reu 2903 df-rmo 2904 df-rab 2905 df-v 3175 df-sbc 3403 df-csb 3500 df-dif 3543 df-un 3545 df-in 3547 df-ss 3554 df-pss 3556 df-nul 3875 df-if 4037 df-pw 4110 df-sn 4126 df-pr 4128 df-tp 4130 df-op 4132 df-uni 4373 df-iun 4457 df-br 4584 df-opab 4644 df-mpt 4645 df-tr 4681 df-eprel 4949 df-id 4953 df-po 4959 df-so 4960 df-fr 4997 df-we 4999 df-xp 5044 df-rel 5045 df-cnv 5046 df-co 5047 df-dm 5048 df-rn 5049 df-res 5050 df-ima 5051 df-pred 5597 df-ord 5643 df-on 5644 df-lim 5645 df-suc 5646 df-iota 5768 df-fun 5806 df-fn 5807 df-f 5808 df-f1 5809 df-fo 5810 df-f1o 5811 df-fv 5812 df-riota 6511 df-ov 6552 df-oprab 6553 df-mpt2 6554 df-om 6958 df-2nd 7060 df-wrecs 7294 df-recs 7355 df-rdg 7393 df-er 7629 df-en 7842 df-dom 7843 df-sdom 7844 df-sup 8231 df-inf 8232 df-pnf 9955 df-mnf 9956 df-xr 9957 df-ltxr 9958 df-le 9959 df-sub 10147 df-neg 10148 df-div 10564 df-nn 10898 df-2 10956 df-3 10957 df-n0 11170 df-z 11255 df-uz 11564 df-rp 11709 df-fl 12455 df-mod 12531 df-seq 12664 df-exp 12723 df-cj 13687 df-re 13688 df-im 13689 df-sqrt 13823 df-abs 13824 df-dvds 14822 df-gcd 15055 df-lcm 15141

This theorem is referenced by: (None)

W3C validator