| Step | Hyp | Ref
 | Expression | 
| 1 |   | gcdcl 12133 | 
. . . . . 6
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 gcd 𝑁) ∈
ℕ0) | 
| 2 | 1 | nn0ge0d 9305 | 
. . . . 5
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → 0 ≤
(𝑀 gcd 𝑁)) | 
| 3 |   | gcddvds 12130 | 
. . . . 5
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝑀 gcd 𝑁) ∥ 𝑀 ∧ (𝑀 gcd 𝑁) ∥ 𝑁)) | 
| 4 |   | 3anass 984 | 
. . . . . . . 8
⊢ ((𝑒 ∈ ℤ ∧ 𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ↔ (𝑒 ∈ ℤ ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈
ℤ))) | 
| 5 |   | ancom 266 | 
. . . . . . . 8
⊢ ((𝑒 ∈ ℤ ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) ↔ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ 𝑒 ∈
ℤ)) | 
| 6 | 4, 5 | bitri 184 | 
. . . . . . 7
⊢ ((𝑒 ∈ ℤ ∧ 𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ↔ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ 𝑒 ∈
ℤ)) | 
| 7 |   | dvdsgcd 12179 | 
. . . . . . 7
⊢ ((𝑒 ∈ ℤ ∧ 𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ (𝑀 gcd 𝑁))) | 
| 8 | 6, 7 | sylbir 135 | 
. . . . . 6
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ 𝑒 ∈ ℤ) → ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ (𝑀 gcd 𝑁))) | 
| 9 | 8 | ralrimiva 2570 | 
. . . . 5
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) →
∀𝑒 ∈ ℤ
((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ (𝑀 gcd 𝑁))) | 
| 10 | 2, 3, 9 | 3jca 1179 | 
. . . 4
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (0 ≤
(𝑀 gcd 𝑁) ∧ ((𝑀 gcd 𝑁) ∥ 𝑀 ∧ (𝑀 gcd 𝑁) ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ (𝑀 gcd 𝑁)))) | 
| 11 | 10 | adantr 276 | 
. . 3
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ 𝐷 = (𝑀 gcd 𝑁)) → (0 ≤ (𝑀 gcd 𝑁) ∧ ((𝑀 gcd 𝑁) ∥ 𝑀 ∧ (𝑀 gcd 𝑁) ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ (𝑀 gcd 𝑁)))) | 
| 12 |   | breq2 4037 | 
. . . . 5
⊢ (𝐷 = (𝑀 gcd 𝑁) → (0 ≤ 𝐷 ↔ 0 ≤ (𝑀 gcd 𝑁))) | 
| 13 |   | breq1 4036 | 
. . . . . 6
⊢ (𝐷 = (𝑀 gcd 𝑁) → (𝐷 ∥ 𝑀 ↔ (𝑀 gcd 𝑁) ∥ 𝑀)) | 
| 14 |   | breq1 4036 | 
. . . . . 6
⊢ (𝐷 = (𝑀 gcd 𝑁) → (𝐷 ∥ 𝑁 ↔ (𝑀 gcd 𝑁) ∥ 𝑁)) | 
| 15 | 13, 14 | anbi12d 473 | 
. . . . 5
⊢ (𝐷 = (𝑀 gcd 𝑁) → ((𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ↔ ((𝑀 gcd 𝑁) ∥ 𝑀 ∧ (𝑀 gcd 𝑁) ∥ 𝑁))) | 
| 16 |   | breq2 4037 | 
. . . . . . 7
⊢ (𝐷 = (𝑀 gcd 𝑁) → (𝑒 ∥ 𝐷 ↔ 𝑒 ∥ (𝑀 gcd 𝑁))) | 
| 17 | 16 | imbi2d 230 | 
. . . . . 6
⊢ (𝐷 = (𝑀 gcd 𝑁) → (((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷) ↔ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ (𝑀 gcd 𝑁)))) | 
| 18 | 17 | ralbidv 2497 | 
. . . . 5
⊢ (𝐷 = (𝑀 gcd 𝑁) → (∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷) ↔ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ (𝑀 gcd 𝑁)))) | 
| 19 | 12, 15, 18 | 3anbi123d 1323 | 
. . . 4
⊢ (𝐷 = (𝑀 gcd 𝑁) → ((0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)) ↔ (0 ≤ (𝑀 gcd 𝑁) ∧ ((𝑀 gcd 𝑁) ∥ 𝑀 ∧ (𝑀 gcd 𝑁) ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ (𝑀 gcd 𝑁))))) | 
| 20 | 19 | adantl 277 | 
. . 3
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ 𝐷 = (𝑀 gcd 𝑁)) → ((0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)) ↔ (0 ≤ (𝑀 gcd 𝑁) ∧ ((𝑀 gcd 𝑁) ∥ 𝑀 ∧ (𝑀 gcd 𝑁) ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ (𝑀 gcd 𝑁))))) | 
| 21 | 11, 20 | mpbird 167 | 
. 2
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ 𝐷 = (𝑀 gcd 𝑁)) → (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷))) | 
| 22 |   | gcdval 12126 | 
. . . 4
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 gcd 𝑁) = if((𝑀 = 0 ∧ 𝑁 = 0), 0, sup({𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)}, ℝ, < ))) | 
| 23 | 22 | adantr 276 | 
. . 3
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷))) → (𝑀 gcd 𝑁) = if((𝑀 = 0 ∧ 𝑁 = 0), 0, sup({𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)}, ℝ, < ))) | 
| 24 |   | iftrue 3566 | 
. . . . . . 7
⊢ ((𝑀 = 0 ∧ 𝑁 = 0) → if((𝑀 = 0 ∧ 𝑁 = 0), 0, sup({𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)}, ℝ, < )) = 0) | 
| 25 | 24 | adantr 276 | 
. . . . . 6
⊢ (((𝑀 = 0 ∧ 𝑁 = 0) ∧ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) → if((𝑀 = 0 ∧ 𝑁 = 0), 0, sup({𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)}, ℝ, < )) = 0) | 
| 26 |   | breq2 4037 | 
. . . . . . . . . . 11
⊢ (𝑀 = 0 → (𝐷 ∥ 𝑀 ↔ 𝐷 ∥ 0)) | 
| 27 |   | breq2 4037 | 
. . . . . . . . . . 11
⊢ (𝑁 = 0 → (𝐷 ∥ 𝑁 ↔ 𝐷 ∥ 0)) | 
| 28 | 26, 27 | bi2anan9 606 | 
. . . . . . . . . 10
⊢ ((𝑀 = 0 ∧ 𝑁 = 0) → ((𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ↔ (𝐷 ∥ 0 ∧ 𝐷 ∥ 0))) | 
| 29 |   | breq2 4037 | 
. . . . . . . . . . . . 13
⊢ (𝑀 = 0 → (𝑒 ∥ 𝑀 ↔ 𝑒 ∥ 0)) | 
| 30 |   | breq2 4037 | 
. . . . . . . . . . . . 13
⊢ (𝑁 = 0 → (𝑒 ∥ 𝑁 ↔ 𝑒 ∥ 0)) | 
| 31 | 29, 30 | bi2anan9 606 | 
. . . . . . . . . . . 12
⊢ ((𝑀 = 0 ∧ 𝑁 = 0) → ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) ↔ (𝑒 ∥ 0 ∧ 𝑒 ∥ 0))) | 
| 32 | 31 | imbi1d 231 | 
. . . . . . . . . . 11
⊢ ((𝑀 = 0 ∧ 𝑁 = 0) → (((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷) ↔ ((𝑒 ∥ 0 ∧ 𝑒 ∥ 0) → 𝑒 ∥ 𝐷))) | 
| 33 | 32 | ralbidv 2497 | 
. . . . . . . . . 10
⊢ ((𝑀 = 0 ∧ 𝑁 = 0) → (∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷) ↔ ∀𝑒 ∈ ℤ ((𝑒 ∥ 0 ∧ 𝑒 ∥ 0) → 𝑒 ∥ 𝐷))) | 
| 34 | 28, 33 | 3anbi23d 1326 | 
. . . . . . . . 9
⊢ ((𝑀 = 0 ∧ 𝑁 = 0) → ((0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)) ↔ (0 ≤ 𝐷 ∧ (𝐷 ∥ 0 ∧ 𝐷 ∥ 0) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 0 ∧ 𝑒 ∥ 0) → 𝑒 ∥ 𝐷)))) | 
| 35 |   | dvdszrcl 11957 | 
. . . . . . . . . . . . 13
⊢ (𝐷 ∥ 0 → (𝐷 ∈ ℤ ∧ 0 ∈
ℤ)) | 
| 36 |   | dvds0 11971 | 
. . . . . . . . . . . . . . . . . . . 20
⊢ (𝑒 ∈ ℤ → 𝑒 ∥ 0) | 
| 37 | 36, 36 | jca 306 | 
. . . . . . . . . . . . . . . . . . 19
⊢ (𝑒 ∈ ℤ → (𝑒 ∥ 0 ∧ 𝑒 ∥ 0)) | 
| 38 | 37 | adantl 277 | 
. . . . . . . . . . . . . . . . . 18
⊢ (((𝐷 ∈ ℤ ∧ 0 ≤
𝐷) ∧ 𝑒 ∈ ℤ) → (𝑒 ∥ 0 ∧ 𝑒 ∥ 0)) | 
| 39 |   | pm5.5 242 | 
. . . . . . . . . . . . . . . . . 18
⊢ ((𝑒 ∥ 0 ∧ 𝑒 ∥ 0) → (((𝑒 ∥ 0 ∧ 𝑒 ∥ 0) → 𝑒 ∥ 𝐷) ↔ 𝑒 ∥ 𝐷)) | 
| 40 | 38, 39 | syl 14 | 
. . . . . . . . . . . . . . . . 17
⊢ (((𝐷 ∈ ℤ ∧ 0 ≤
𝐷) ∧ 𝑒 ∈ ℤ) → (((𝑒 ∥ 0 ∧ 𝑒 ∥ 0) → 𝑒 ∥ 𝐷) ↔ 𝑒 ∥ 𝐷)) | 
| 41 | 40 | ralbidva 2493 | 
. . . . . . . . . . . . . . . 16
⊢ ((𝐷 ∈ ℤ ∧ 0 ≤
𝐷) → (∀𝑒 ∈ ℤ ((𝑒 ∥ 0 ∧ 𝑒 ∥ 0) → 𝑒 ∥ 𝐷) ↔ ∀𝑒 ∈ ℤ 𝑒 ∥ 𝐷)) | 
| 42 |   | 0z 9337 | 
. . . . . . . . . . . . . . . . . . 19
⊢ 0 ∈
ℤ | 
| 43 |   | breq1 4036 | 
. . . . . . . . . . . . . . . . . . . 20
⊢ (𝑒 = 0 → (𝑒 ∥ 𝐷 ↔ 0 ∥ 𝐷)) | 
| 44 | 43 | rspcv 2864 | 
. . . . . . . . . . . . . . . . . . 19
⊢ (0 ∈
ℤ → (∀𝑒
∈ ℤ 𝑒 ∥
𝐷 → 0 ∥ 𝐷)) | 
| 45 | 42, 44 | ax-mp 5 | 
. . . . . . . . . . . . . . . . . 18
⊢
(∀𝑒 ∈
ℤ 𝑒 ∥ 𝐷 → 0 ∥ 𝐷) | 
| 46 |   | 0dvds 11976 | 
. . . . . . . . . . . . . . . . . . . 20
⊢ (𝐷 ∈ ℤ → (0
∥ 𝐷 ↔ 𝐷 = 0)) | 
| 47 | 46 | biimpd 144 | 
. . . . . . . . . . . . . . . . . . 19
⊢ (𝐷 ∈ ℤ → (0
∥ 𝐷 → 𝐷 = 0)) | 
| 48 |   | eqcom 2198 | 
. . . . . . . . . . . . . . . . . . 19
⊢ (0 =
𝐷 ↔ 𝐷 = 0) | 
| 49 | 47, 48 | imbitrrdi 162 | 
. . . . . . . . . . . . . . . . . 18
⊢ (𝐷 ∈ ℤ → (0
∥ 𝐷 → 0 = 𝐷)) | 
| 50 | 45, 49 | syl5 32 | 
. . . . . . . . . . . . . . . . 17
⊢ (𝐷 ∈ ℤ →
(∀𝑒 ∈ ℤ
𝑒 ∥ 𝐷 → 0 = 𝐷)) | 
| 51 | 50 | adantr 276 | 
. . . . . . . . . . . . . . . 16
⊢ ((𝐷 ∈ ℤ ∧ 0 ≤
𝐷) → (∀𝑒 ∈ ℤ 𝑒 ∥ 𝐷 → 0 = 𝐷)) | 
| 52 | 41, 51 | sylbid 150 | 
. . . . . . . . . . . . . . 15
⊢ ((𝐷 ∈ ℤ ∧ 0 ≤
𝐷) → (∀𝑒 ∈ ℤ ((𝑒 ∥ 0 ∧ 𝑒 ∥ 0) → 𝑒 ∥ 𝐷) → 0 = 𝐷)) | 
| 53 | 52 | ex 115 | 
. . . . . . . . . . . . . 14
⊢ (𝐷 ∈ ℤ → (0 ≤
𝐷 → (∀𝑒 ∈ ℤ ((𝑒 ∥ 0 ∧ 𝑒 ∥ 0) → 𝑒 ∥ 𝐷) → 0 = 𝐷))) | 
| 54 | 53 | adantr 276 | 
. . . . . . . . . . . . 13
⊢ ((𝐷 ∈ ℤ ∧ 0 ∈
ℤ) → (0 ≤ 𝐷
→ (∀𝑒 ∈
ℤ ((𝑒 ∥ 0 ∧
𝑒 ∥ 0) → 𝑒 ∥ 𝐷) → 0 = 𝐷))) | 
| 55 | 35, 54 | syl 14 | 
. . . . . . . . . . . 12
⊢ (𝐷 ∥ 0 → (0 ≤ 𝐷 → (∀𝑒 ∈ ℤ ((𝑒 ∥ 0 ∧ 𝑒 ∥ 0) → 𝑒 ∥ 𝐷) → 0 = 𝐷))) | 
| 56 | 55 | adantr 276 | 
. . . . . . . . . . 11
⊢ ((𝐷 ∥ 0 ∧ 𝐷 ∥ 0) → (0 ≤ 𝐷 → (∀𝑒 ∈ ℤ ((𝑒 ∥ 0 ∧ 𝑒 ∥ 0) → 𝑒 ∥ 𝐷) → 0 = 𝐷))) | 
| 57 | 56 | com12 30 | 
. . . . . . . . . 10
⊢ (0 ≤
𝐷 → ((𝐷 ∥ 0 ∧ 𝐷 ∥ 0) →
(∀𝑒 ∈ ℤ
((𝑒 ∥ 0 ∧ 𝑒 ∥ 0) → 𝑒 ∥ 𝐷) → 0 = 𝐷))) | 
| 58 | 57 | 3imp 1195 | 
. . . . . . . . 9
⊢ ((0 ≤
𝐷 ∧ (𝐷 ∥ 0 ∧ 𝐷 ∥ 0) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 0 ∧ 𝑒 ∥ 0) → 𝑒 ∥ 𝐷)) → 0 = 𝐷) | 
| 59 | 34, 58 | biimtrdi 163 | 
. . . . . . . 8
⊢ ((𝑀 = 0 ∧ 𝑁 = 0) → ((0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)) → 0 = 𝐷)) | 
| 60 | 59 | adantld 278 | 
. . . . . . 7
⊢ ((𝑀 = 0 ∧ 𝑁 = 0) → (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷))) → 0 = 𝐷)) | 
| 61 | 60 | imp 124 | 
. . . . . 6
⊢ (((𝑀 = 0 ∧ 𝑁 = 0) ∧ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) → 0 = 𝐷) | 
| 62 | 25, 61 | eqtrd 2229 | 
. . . . 5
⊢ (((𝑀 = 0 ∧ 𝑁 = 0) ∧ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) → if((𝑀 = 0 ∧ 𝑁 = 0), 0, sup({𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)}, ℝ, < )) = 𝐷) | 
| 63 | 62 | ancoms 268 | 
. . . 4
⊢ ((((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷))) ∧ (𝑀 = 0 ∧ 𝑁 = 0)) → if((𝑀 = 0 ∧ 𝑁 = 0), 0, sup({𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)}, ℝ, < )) = 𝐷) | 
| 64 |   | iffalse 3569 | 
. . . . . . 7
⊢ (¬
(𝑀 = 0 ∧ 𝑁 = 0) → if((𝑀 = 0 ∧ 𝑁 = 0), 0, sup({𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)}, ℝ, < )) = sup({𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)}, ℝ, < )) | 
| 65 | 64 | adantr 276 | 
. . . . . 6
⊢ ((¬
(𝑀 = 0 ∧ 𝑁 = 0) ∧ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) → if((𝑀 = 0 ∧ 𝑁 = 0), 0, sup({𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)}, ℝ, < )) = sup({𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)}, ℝ, < )) | 
| 66 |   | lttri3 8106 | 
. . . . . . . 8
⊢ ((𝑓 ∈ ℝ ∧ 𝑔 ∈ ℝ) → (𝑓 = 𝑔 ↔ (¬ 𝑓 < 𝑔 ∧ ¬ 𝑔 < 𝑓))) | 
| 67 | 66 | adantl 277 | 
. . . . . . 7
⊢ (((¬
(𝑀 = 0 ∧ 𝑁 = 0) ∧ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) ∧ (𝑓 ∈ ℝ ∧ 𝑔 ∈ ℝ)) → (𝑓 = 𝑔 ↔ (¬ 𝑓 < 𝑔 ∧ ¬ 𝑔 < 𝑓))) | 
| 68 |   | dvdszrcl 11957 | 
. . . . . . . . . . . 12
⊢ (𝐷 ∥ 𝑀 → (𝐷 ∈ ℤ ∧ 𝑀 ∈ ℤ)) | 
| 69 | 68 | simpld 112 | 
. . . . . . . . . . 11
⊢ (𝐷 ∥ 𝑀 → 𝐷 ∈ ℤ) | 
| 70 | 69 | zred 9448 | 
. . . . . . . . . 10
⊢ (𝐷 ∥ 𝑀 → 𝐷 ∈ ℝ) | 
| 71 | 70 | adantr 276 | 
. . . . . . . . 9
⊢ ((𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) → 𝐷 ∈ ℝ) | 
| 72 | 71 | 3ad2ant2 1021 | 
. . . . . . . 8
⊢ ((0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)) → 𝐷 ∈ ℝ) | 
| 73 | 72 | ad2antll 491 | 
. . . . . . 7
⊢ ((¬
(𝑀 = 0 ∧ 𝑁 = 0) ∧ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) → 𝐷 ∈ ℝ) | 
| 74 |   | breq1 4036 | 
. . . . . . . . . . 11
⊢ (𝑛 = 𝑦 → (𝑛 ∥ 𝑀 ↔ 𝑦 ∥ 𝑀)) | 
| 75 |   | breq1 4036 | 
. . . . . . . . . . 11
⊢ (𝑛 = 𝑦 → (𝑛 ∥ 𝑁 ↔ 𝑦 ∥ 𝑁)) | 
| 76 | 74, 75 | anbi12d 473 | 
. . . . . . . . . 10
⊢ (𝑛 = 𝑦 → ((𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁) ↔ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁))) | 
| 77 | 76 | elrab 2920 | 
. . . . . . . . 9
⊢ (𝑦 ∈ {𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)} ↔ (𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁))) | 
| 78 |   | breq1 4036 | 
. . . . . . . . . . . . . . . . . . . . 21
⊢ (𝑒 = 𝑦 → (𝑒 ∥ 𝑀 ↔ 𝑦 ∥ 𝑀)) | 
| 79 |   | breq1 4036 | 
. . . . . . . . . . . . . . . . . . . . 21
⊢ (𝑒 = 𝑦 → (𝑒 ∥ 𝑁 ↔ 𝑦 ∥ 𝑁)) | 
| 80 | 78, 79 | anbi12d 473 | 
. . . . . . . . . . . . . . . . . . . 20
⊢ (𝑒 = 𝑦 → ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) ↔ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁))) | 
| 81 |   | breq1 4036 | 
. . . . . . . . . . . . . . . . . . . 20
⊢ (𝑒 = 𝑦 → (𝑒 ∥ 𝐷 ↔ 𝑦 ∥ 𝐷)) | 
| 82 | 80, 81 | imbi12d 234 | 
. . . . . . . . . . . . . . . . . . 19
⊢ (𝑒 = 𝑦 → (((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷) ↔ ((𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁) → 𝑦 ∥ 𝐷))) | 
| 83 | 82 | rspcv 2864 | 
. . . . . . . . . . . . . . . . . 18
⊢ (𝑦 ∈ ℤ →
(∀𝑒 ∈ ℤ
((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷) → ((𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁) → 𝑦 ∥ 𝐷))) | 
| 84 | 83 | com23 78 | 
. . . . . . . . . . . . . . . . 17
⊢ (𝑦 ∈ ℤ → ((𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁) → (∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷) → 𝑦 ∥ 𝐷))) | 
| 85 | 84 | imp 124 | 
. . . . . . . . . . . . . . . 16
⊢ ((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) → (∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷) → 𝑦 ∥ 𝐷)) | 
| 86 | 85 | ad2antrr 488 | 
. . . . . . . . . . . . . . 15
⊢ ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → (∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷) → 𝑦 ∥ 𝐷)) | 
| 87 |   | elnn0z 9339 | 
. . . . . . . . . . . . . . . . . . . . . 22
⊢ (𝐷 ∈ ℕ0
↔ (𝐷 ∈ ℤ
∧ 0 ≤ 𝐷)) | 
| 88 | 87 | simplbi2 385 | 
. . . . . . . . . . . . . . . . . . . . 21
⊢ (𝐷 ∈ ℤ → (0 ≤
𝐷 → 𝐷 ∈
ℕ0)) | 
| 89 | 88 | adantr 276 | 
. . . . . . . . . . . . . . . . . . . 20
⊢ ((𝐷 ∈ ℤ ∧ 𝑀 ∈ ℤ) → (0 ≤
𝐷 → 𝐷 ∈
ℕ0)) | 
| 90 | 68, 89 | syl 14 | 
. . . . . . . . . . . . . . . . . . 19
⊢ (𝐷 ∥ 𝑀 → (0 ≤ 𝐷 → 𝐷 ∈
ℕ0)) | 
| 91 | 90 | adantr 276 | 
. . . . . . . . . . . . . . . . . 18
⊢ ((𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) → (0 ≤ 𝐷 → 𝐷 ∈
ℕ0)) | 
| 92 | 91 | impcom 125 | 
. . . . . . . . . . . . . . . . 17
⊢ ((0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) → 𝐷 ∈
ℕ0) | 
| 93 |   | zre 9330 | 
. . . . . . . . . . . . . . . . . . . . 21
⊢ (𝑦 ∈ ℤ → 𝑦 ∈
ℝ) | 
| 94 | 93 | ad2antrr 488 | 
. . . . . . . . . . . . . . . . . . . 20
⊢ (((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) → 𝑦 ∈ ℝ) | 
| 95 | 94 | ad2antrl 490 | 
. . . . . . . . . . . . . . . . . . 19
⊢ ((((0
≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) ∧ (𝑦 ∥ 𝐷 ∧ 𝐷 ∈ ℕ0)) ∧ (((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ))) → 𝑦 ∈ ℝ) | 
| 96 | 71 | ad3antlr 493 | 
. . . . . . . . . . . . . . . . . . 19
⊢ ((((0
≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) ∧ (𝑦 ∥ 𝐷 ∧ 𝐷 ∈ ℕ0)) ∧ (((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ))) → 𝐷 ∈ ℝ) | 
| 97 |   | simp-5l 543 | 
. . . . . . . . . . . . . . . . . . . . . . . . 25
⊢
((((((𝑦 ∈
ℤ ∧ (𝑦 ∥
𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) ∧ 𝐷 ∈ ℕ0) ∧ (0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁))) → 𝑦 ∈ ℤ) | 
| 98 |   | elnn0 9251 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ (𝐷 ∈ ℕ0
↔ (𝐷 ∈ ℕ
∨ 𝐷 =
0)) | 
| 99 |   | 2a1 25 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
⊢ (𝐷 ∈ ℕ → ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → ((0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) → 𝐷 ∈ ℕ))) | 
| 100 |   | breq1 4036 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
⊢ (𝐷 = 0 → (𝐷 ∥ 𝑀 ↔ 0 ∥ 𝑀)) | 
| 101 |   | breq1 4036 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
⊢ (𝐷 = 0 → (𝐷 ∥ 𝑁 ↔ 0 ∥ 𝑁)) | 
| 102 | 100, 101 | anbi12d 473 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33
⊢ (𝐷 = 0 → ((𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ↔ (0 ∥ 𝑀 ∧ 0 ∥ 𝑁))) | 
| 103 | 102 | anbi2d 464 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
⊢ (𝐷 = 0 → ((0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) ↔ (0 ≤ 𝐷 ∧ (0 ∥ 𝑀 ∧ 0 ∥ 𝑁)))) | 
| 104 | 103 | adantr 276 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ ((𝐷 = 0 ∧ (((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ))) → ((0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) ↔ (0 ≤ 𝐷 ∧ (0 ∥ 𝑀 ∧ 0 ∥ 𝑁)))) | 
| 105 |   | simplr 528 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 35
⊢ ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → ¬ (𝑀 = 0 ∧ 𝑁 = 0)) | 
| 106 |   | zdceq 9401 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . 38
⊢ ((𝑀 ∈ ℤ ∧ 0 ∈
ℤ) → DECID 𝑀 = 0) | 
| 107 | 42, 106 | mpan2 425 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . 37
⊢ (𝑀 ∈ ℤ →
DECID 𝑀 =
0) | 
| 108 |   | ianordc 900 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . 37
⊢
(DECID 𝑀 = 0 → (¬ (𝑀 = 0 ∧ 𝑁 = 0) ↔ (¬ 𝑀 = 0 ∨ ¬ 𝑁 = 0))) | 
| 109 | 107, 108 | syl 14 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . 36
⊢ (𝑀 ∈ ℤ → (¬
(𝑀 = 0 ∧ 𝑁 = 0) ↔ (¬ 𝑀 = 0 ∨ ¬ 𝑁 = 0))) | 
| 110 | 109 | ad2antrl 490 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 35
⊢ ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → (¬ (𝑀 = 0 ∧ 𝑁 = 0) ↔ (¬ 𝑀 = 0 ∨ ¬ 𝑁 = 0))) | 
| 111 | 105, 110 | mpbid 147 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
⊢ ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → (¬ 𝑀 = 0 ∨ ¬ 𝑁 = 0)) | 
| 112 |   | dvdszrcl 11957 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . 38
⊢ (0
∥ 𝑀 → (0 ∈
ℤ ∧ 𝑀 ∈
ℤ)) | 
| 113 |   | 0dvds 11976 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . 40
⊢ (𝑀 ∈ ℤ → (0
∥ 𝑀 ↔ 𝑀 = 0)) | 
| 114 |   | pm2.24 622 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . 40
⊢ (𝑀 = 0 → (¬ 𝑀 = 0 → 𝐷 ∈ ℕ)) | 
| 115 | 113, 114 | biimtrdi 163 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . 39
⊢ (𝑀 ∈ ℤ → (0
∥ 𝑀 → (¬
𝑀 = 0 → 𝐷 ∈
ℕ))) | 
| 116 | 115 | adantl 277 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . 38
⊢ ((0
∈ ℤ ∧ 𝑀
∈ ℤ) → (0 ∥ 𝑀 → (¬ 𝑀 = 0 → 𝐷 ∈ ℕ))) | 
| 117 | 112, 116 | mpcom 36 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . 37
⊢ (0
∥ 𝑀 → (¬
𝑀 = 0 → 𝐷 ∈
ℕ)) | 
| 118 | 117 | adantr 276 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . 36
⊢ ((0
∥ 𝑀 ∧ 0 ∥
𝑁) → (¬ 𝑀 = 0 → 𝐷 ∈ ℕ)) | 
| 119 | 118 | com12 30 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 35
⊢ (¬
𝑀 = 0 → ((0 ∥
𝑀 ∧ 0 ∥ 𝑁) → 𝐷 ∈ ℕ)) | 
| 120 |   | dvdszrcl 11957 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . 38
⊢ (0
∥ 𝑁 → (0 ∈
ℤ ∧ 𝑁 ∈
ℤ)) | 
| 121 |   | 0dvds 11976 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . 40
⊢ (𝑁 ∈ ℤ → (0
∥ 𝑁 ↔ 𝑁 = 0)) | 
| 122 |   | pm2.24 622 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . 40
⊢ (𝑁 = 0 → (¬ 𝑁 = 0 → 𝐷 ∈ ℕ)) | 
| 123 | 121, 122 | biimtrdi 163 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . 39
⊢ (𝑁 ∈ ℤ → (0
∥ 𝑁 → (¬
𝑁 = 0 → 𝐷 ∈
ℕ))) | 
| 124 | 123 | adantl 277 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . 38
⊢ ((0
∈ ℤ ∧ 𝑁
∈ ℤ) → (0 ∥ 𝑁 → (¬ 𝑁 = 0 → 𝐷 ∈ ℕ))) | 
| 125 | 120, 124 | mpcom 36 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . 37
⊢ (0
∥ 𝑁 → (¬
𝑁 = 0 → 𝐷 ∈
ℕ)) | 
| 126 | 125 | adantl 277 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . 36
⊢ ((0
∥ 𝑀 ∧ 0 ∥
𝑁) → (¬ 𝑁 = 0 → 𝐷 ∈ ℕ)) | 
| 127 | 126 | com12 30 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 35
⊢ (¬
𝑁 = 0 → ((0 ∥
𝑀 ∧ 0 ∥ 𝑁) → 𝐷 ∈ ℕ)) | 
| 128 | 119, 127 | jaoi 717 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
⊢ ((¬
𝑀 = 0 ∨ ¬ 𝑁 = 0) → ((0 ∥ 𝑀 ∧ 0 ∥ 𝑁) → 𝐷 ∈ ℕ)) | 
| 129 | 111, 128 | syl 14 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33
⊢ ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → ((0 ∥ 𝑀 ∧ 0 ∥ 𝑁) → 𝐷 ∈ ℕ)) | 
| 130 | 129 | adantld 278 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
⊢ ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → ((0 ≤ 𝐷 ∧ (0 ∥ 𝑀 ∧ 0 ∥ 𝑁)) → 𝐷 ∈ ℕ)) | 
| 131 | 130 | adantl 277 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ ((𝐷 = 0 ∧ (((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ))) → ((0 ≤ 𝐷 ∧ (0 ∥ 𝑀 ∧ 0 ∥ 𝑁)) → 𝐷 ∈ ℕ)) | 
| 132 | 104, 131 | sylbid 150 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
⊢ ((𝐷 = 0 ∧ (((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ))) → ((0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) → 𝐷 ∈ ℕ)) | 
| 133 | 132 | ex 115 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
⊢ (𝐷 = 0 → ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → ((0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) → 𝐷 ∈ ℕ))) | 
| 134 | 99, 133 | jaoi 717 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ ((𝐷 ∈ ℕ ∨ 𝐷 = 0) → ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → ((0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) → 𝐷 ∈ ℕ))) | 
| 135 | 98, 134 | sylbi 121 | 
. . . . . . . . . . . . . . . . . . . . . . . . . . 27
⊢ (𝐷 ∈ ℕ0
→ ((((𝑦 ∈ ℤ
∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → ((0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) → 𝐷 ∈ ℕ))) | 
| 136 | 135 | impcom 125 | 
. . . . . . . . . . . . . . . . . . . . . . . . . 26
⊢
(((((𝑦 ∈
ℤ ∧ (𝑦 ∥
𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) ∧ 𝐷 ∈ ℕ0) → ((0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) → 𝐷 ∈ ℕ)) | 
| 137 | 136 | imp 124 | 
. . . . . . . . . . . . . . . . . . . . . . . . 25
⊢
((((((𝑦 ∈
ℤ ∧ (𝑦 ∥
𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) ∧ 𝐷 ∈ ℕ0) ∧ (0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁))) → 𝐷 ∈ ℕ) | 
| 138 |   | dvdsle 12009 | 
. . . . . . . . . . . . . . . . . . . . . . . . 25
⊢ ((𝑦 ∈ ℤ ∧ 𝐷 ∈ ℕ) → (𝑦 ∥ 𝐷 → 𝑦 ≤ 𝐷)) | 
| 139 | 97, 137, 138 | syl2anc 411 | 
. . . . . . . . . . . . . . . . . . . . . . . 24
⊢
((((((𝑦 ∈
ℤ ∧ (𝑦 ∥
𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) ∧ 𝐷 ∈ ℕ0) ∧ (0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁))) → (𝑦 ∥ 𝐷 → 𝑦 ≤ 𝐷)) | 
| 140 | 139 | exp31 364 | 
. . . . . . . . . . . . . . . . . . . . . . 23
⊢ ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → (𝐷 ∈ ℕ0 → ((0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) → (𝑦 ∥ 𝐷 → 𝑦 ≤ 𝐷)))) | 
| 141 | 140 | com14 88 | 
. . . . . . . . . . . . . . . . . . . . . 22
⊢ (𝑦 ∥ 𝐷 → (𝐷 ∈ ℕ0 → ((0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) → ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → 𝑦 ≤ 𝐷)))) | 
| 142 | 141 | imp 124 | 
. . . . . . . . . . . . . . . . . . . . 21
⊢ ((𝑦 ∥ 𝐷 ∧ 𝐷 ∈ ℕ0) → ((0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) → ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → 𝑦 ≤ 𝐷))) | 
| 143 | 142 | impcom 125 | 
. . . . . . . . . . . . . . . . . . . 20
⊢ (((0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) ∧ (𝑦 ∥ 𝐷 ∧ 𝐷 ∈ ℕ0)) →
((((𝑦 ∈ ℤ ∧
(𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → 𝑦 ≤ 𝐷)) | 
| 144 | 143 | imp 124 | 
. . . . . . . . . . . . . . . . . . 19
⊢ ((((0
≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) ∧ (𝑦 ∥ 𝐷 ∧ 𝐷 ∈ ℕ0)) ∧ (((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ))) → 𝑦 ≤ 𝐷) | 
| 145 | 95, 96, 144 | lensymd 8148 | 
. . . . . . . . . . . . . . . . . 18
⊢ ((((0
≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) ∧ (𝑦 ∥ 𝐷 ∧ 𝐷 ∈ ℕ0)) ∧ (((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ))) → ¬ 𝐷 < 𝑦) | 
| 146 | 145 | exp31 364 | 
. . . . . . . . . . . . . . . . 17
⊢ ((0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) → ((𝑦 ∥ 𝐷 ∧ 𝐷 ∈ ℕ0) →
((((𝑦 ∈ ℤ ∧
(𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → ¬ 𝐷 < 𝑦))) | 
| 147 | 92, 146 | mpan2d 428 | 
. . . . . . . . . . . . . . . 16
⊢ ((0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) → (𝑦 ∥ 𝐷 → ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → ¬ 𝐷 < 𝑦))) | 
| 148 | 147 | com13 80 | 
. . . . . . . . . . . . . . 15
⊢ ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → (𝑦 ∥ 𝐷 → ((0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) → ¬ 𝐷 < 𝑦))) | 
| 149 | 86, 148 | syld 45 | 
. . . . . . . . . . . . . 14
⊢ ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → (∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷) → ((0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) → ¬ 𝐷 < 𝑦))) | 
| 150 | 149 | com13 80 | 
. . . . . . . . . . . . 13
⊢ ((0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁)) → (∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷) → ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → ¬ 𝐷 < 𝑦))) | 
| 151 | 150 | 3impia 1202 | 
. . . . . . . . . . . 12
⊢ ((0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)) → ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → ¬ 𝐷 < 𝑦)) | 
| 152 | 151 | com12 30 | 
. . . . . . . . . . 11
⊢ ((((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) ∧ (𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ)) → ((0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)) → ¬ 𝐷 < 𝑦)) | 
| 153 | 152 | expimpd 363 | 
. . . . . . . . . 10
⊢ (((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) → (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷))) → ¬ 𝐷 < 𝑦)) | 
| 154 | 153 | expimpd 363 | 
. . . . . . . . 9
⊢ ((𝑦 ∈ ℤ ∧ (𝑦 ∥ 𝑀 ∧ 𝑦 ∥ 𝑁)) → ((¬ (𝑀 = 0 ∧ 𝑁 = 0) ∧ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) → ¬ 𝐷 < 𝑦)) | 
| 155 | 77, 154 | sylbi 121 | 
. . . . . . . 8
⊢ (𝑦 ∈ {𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)} → ((¬ (𝑀 = 0 ∧ 𝑁 = 0) ∧ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) → ¬ 𝐷 < 𝑦)) | 
| 156 | 155 | impcom 125 | 
. . . . . . 7
⊢ (((¬
(𝑀 = 0 ∧ 𝑁 = 0) ∧ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) ∧ 𝑦 ∈ {𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)}) → ¬ 𝐷 < 𝑦) | 
| 157 | 69 | adantr 276 | 
. . . . . . . . . . . . 13
⊢ ((𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) → 𝐷 ∈ ℤ) | 
| 158 | 157 | ancri 324 | 
. . . . . . . . . . . 12
⊢ ((𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) → (𝐷 ∈ ℤ ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁))) | 
| 159 | 158 | 3ad2ant2 1021 | 
. . . . . . . . . . 11
⊢ ((0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)) → (𝐷 ∈ ℤ ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁))) | 
| 160 | 159 | ad2antll 491 | 
. . . . . . . . . 10
⊢ ((¬
(𝑀 = 0 ∧ 𝑁 = 0) ∧ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) → (𝐷 ∈ ℤ ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁))) | 
| 161 | 160 | adantr 276 | 
. . . . . . . . 9
⊢ (((¬
(𝑀 = 0 ∧ 𝑁 = 0) ∧ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) ∧ (𝑦 ∈ ℝ ∧ 𝑦 < 𝐷)) → (𝐷 ∈ ℤ ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁))) | 
| 162 |   | breq1 4036 | 
. . . . . . . . . . 11
⊢ (𝑛 = 𝐷 → (𝑛 ∥ 𝑀 ↔ 𝐷 ∥ 𝑀)) | 
| 163 |   | breq1 4036 | 
. . . . . . . . . . 11
⊢ (𝑛 = 𝐷 → (𝑛 ∥ 𝑁 ↔ 𝐷 ∥ 𝑁)) | 
| 164 | 162, 163 | anbi12d 473 | 
. . . . . . . . . 10
⊢ (𝑛 = 𝐷 → ((𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁) ↔ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁))) | 
| 165 | 164 | elrab 2920 | 
. . . . . . . . 9
⊢ (𝐷 ∈ {𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)} ↔ (𝐷 ∈ ℤ ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁))) | 
| 166 | 161, 165 | sylibr 134 | 
. . . . . . . 8
⊢ (((¬
(𝑀 = 0 ∧ 𝑁 = 0) ∧ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) ∧ (𝑦 ∈ ℝ ∧ 𝑦 < 𝐷)) → 𝐷 ∈ {𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)}) | 
| 167 |   | breq2 4037 | 
. . . . . . . . 9
⊢ (𝑧 = 𝐷 → (𝑦 < 𝑧 ↔ 𝑦 < 𝐷)) | 
| 168 | 167 | adantl 277 | 
. . . . . . . 8
⊢ ((((¬
(𝑀 = 0 ∧ 𝑁 = 0) ∧ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) ∧ (𝑦 ∈ ℝ ∧ 𝑦 < 𝐷)) ∧ 𝑧 = 𝐷) → (𝑦 < 𝑧 ↔ 𝑦 < 𝐷)) | 
| 169 |   | simprr 531 | 
. . . . . . . 8
⊢ (((¬
(𝑀 = 0 ∧ 𝑁 = 0) ∧ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) ∧ (𝑦 ∈ ℝ ∧ 𝑦 < 𝐷)) → 𝑦 < 𝐷) | 
| 170 | 166, 168,
169 | rspcedvd 2874 | 
. . . . . . 7
⊢ (((¬
(𝑀 = 0 ∧ 𝑁 = 0) ∧ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) ∧ (𝑦 ∈ ℝ ∧ 𝑦 < 𝐷)) → ∃𝑧 ∈ {𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)}𝑦 < 𝑧) | 
| 171 | 67, 73, 156, 170 | eqsuptid 7063 | 
. . . . . 6
⊢ ((¬
(𝑀 = 0 ∧ 𝑁 = 0) ∧ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) → sup({𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)}, ℝ, < ) = 𝐷) | 
| 172 | 65, 171 | eqtrd 2229 | 
. . . . 5
⊢ ((¬
(𝑀 = 0 ∧ 𝑁 = 0) ∧ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) → if((𝑀 = 0 ∧ 𝑁 = 0), 0, sup({𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)}, ℝ, < )) = 𝐷) | 
| 173 | 172 | ancoms 268 | 
. . . 4
⊢ ((((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷))) ∧ ¬ (𝑀 = 0 ∧ 𝑁 = 0)) → if((𝑀 = 0 ∧ 𝑁 = 0), 0, sup({𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)}, ℝ, < )) = 𝐷) | 
| 174 |   | gcdmndc 12122 | 
. . . . . 6
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) →
DECID (𝑀 = 0
∧ 𝑁 =
0)) | 
| 175 | 174 | adantr 276 | 
. . . . 5
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷))) → DECID (𝑀 = 0 ∧ 𝑁 = 0)) | 
| 176 |   | exmiddc 837 | 
. . . . 5
⊢
(DECID (𝑀 = 0 ∧ 𝑁 = 0) → ((𝑀 = 0 ∧ 𝑁 = 0) ∨ ¬ (𝑀 = 0 ∧ 𝑁 = 0))) | 
| 177 | 175, 176 | syl 14 | 
. . . 4
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷))) → ((𝑀 = 0 ∧ 𝑁 = 0) ∨ ¬ (𝑀 = 0 ∧ 𝑁 = 0))) | 
| 178 | 63, 173, 177 | mpjaodan 799 | 
. . 3
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷))) → if((𝑀 = 0 ∧ 𝑁 = 0), 0, sup({𝑛 ∈ ℤ ∣ (𝑛 ∥ 𝑀 ∧ 𝑛 ∥ 𝑁)}, ℝ, < )) = 𝐷) | 
| 179 | 23, 178 | eqtr2d 2230 | 
. 2
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (0 ≤
𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷))) → 𝐷 = (𝑀 gcd 𝑁)) | 
| 180 | 21, 179 | impbida 596 | 
1
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝐷 = (𝑀 gcd 𝑁) ↔ (0 ≤ 𝐷 ∧ (𝐷 ∥ 𝑀 ∧ 𝐷 ∥ 𝑁) ∧ ∀𝑒 ∈ ℤ ((𝑒 ∥ 𝑀 ∧ 𝑒 ∥ 𝑁) → 𝑒 ∥ 𝐷)))) |