| Step | Hyp | Ref
 | Expression | 
| 1 |   | oveq1 5929 | 
. . . . . . . . 9
⊢ (𝑥 = 𝐵 → (𝑥 /L 𝑁) = (𝐵 /L 𝑁)) | 
| 2 | 1 | oveq1d 5937 | 
. . . . . . . 8
⊢ (𝑥 = 𝐵 → ((𝑥 /L 𝑁) · (0 /L 𝑁)) = ((𝐵 /L 𝑁) · (0 /L 𝑁))) | 
| 3 | 2 | eqeq2d 2208 | 
. . . . . . 7
⊢ (𝑥 = 𝐵 → ((0 /L 𝑁) = ((𝑥 /L 𝑁) · (0 /L 𝑁)) ↔ (0
/L 𝑁) =
((𝐵 /L
𝑁) · (0
/L 𝑁)))) | 
| 4 |   | id 19 | 
. . . . . . . . . . . . . . 15
⊢ (𝑥 ∈ ℤ → 𝑥 ∈
ℤ) | 
| 5 |   | nn0z 9346 | 
. . . . . . . . . . . . . . 15
⊢ (𝑁 ∈ ℕ0
→ 𝑁 ∈
ℤ) | 
| 6 |   | lgscl 15255 | 
. . . . . . . . . . . . . . 15
⊢ ((𝑥 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑥 /L 𝑁) ∈
ℤ) | 
| 7 | 4, 5, 6 | syl2anr 290 | 
. . . . . . . . . . . . . 14
⊢ ((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
→ (𝑥
/L 𝑁)
∈ ℤ) | 
| 8 | 7 | zcnd 9449 | 
. . . . . . . . . . . . 13
⊢ ((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
→ (𝑥
/L 𝑁)
∈ ℂ) | 
| 9 | 8 | adantr 276 | 
. . . . . . . . . . . 12
⊢ (((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
∧ (0 /L 𝑁) = 0) → (𝑥 /L 𝑁) ∈ ℂ) | 
| 10 | 9 | mul01d 8419 | 
. . . . . . . . . . 11
⊢ (((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
∧ (0 /L 𝑁) = 0) → ((𝑥 /L 𝑁) · 0) = 0) | 
| 11 |   | simpr 110 | 
. . . . . . . . . . . 12
⊢ (((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
∧ (0 /L 𝑁) = 0) → (0 /L 𝑁) = 0) | 
| 12 | 11 | oveq2d 5938 | 
. . . . . . . . . . 11
⊢ (((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
∧ (0 /L 𝑁) = 0) → ((𝑥 /L 𝑁) · (0 /L 𝑁)) = ((𝑥 /L 𝑁) · 0)) | 
| 13 | 10, 12, 11 | 3eqtr4rd 2240 | 
. . . . . . . . . 10
⊢ (((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
∧ (0 /L 𝑁) = 0) → (0 /L 𝑁) = ((𝑥 /L 𝑁) · (0 /L 𝑁))) | 
| 14 |   | 0z 9337 | 
. . . . . . . . . . . . . . 15
⊢ 0 ∈
ℤ | 
| 15 | 5 | adantr 276 | 
. . . . . . . . . . . . . . 15
⊢ ((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
→ 𝑁 ∈
ℤ) | 
| 16 |   | lgsne0 15279 | 
. . . . . . . . . . . . . . 15
⊢ ((0
∈ ℤ ∧ 𝑁
∈ ℤ) → ((0 /L 𝑁) ≠ 0 ↔ (0 gcd 𝑁) = 1)) | 
| 17 | 14, 15, 16 | sylancr 414 | 
. . . . . . . . . . . . . 14
⊢ ((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
→ ((0 /L 𝑁) ≠ 0 ↔ (0 gcd 𝑁) = 1)) | 
| 18 |   | gcdcom 12140 | 
. . . . . . . . . . . . . . . . . 18
⊢ ((0
∈ ℤ ∧ 𝑁
∈ ℤ) → (0 gcd 𝑁) = (𝑁 gcd 0)) | 
| 19 | 14, 15, 18 | sylancr 414 | 
. . . . . . . . . . . . . . . . 17
⊢ ((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
→ (0 gcd 𝑁) = (𝑁 gcd 0)) | 
| 20 |   | nn0gcdid0 12148 | 
. . . . . . . . . . . . . . . . . 18
⊢ (𝑁 ∈ ℕ0
→ (𝑁 gcd 0) = 𝑁) | 
| 21 | 20 | adantr 276 | 
. . . . . . . . . . . . . . . . 17
⊢ ((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
→ (𝑁 gcd 0) = 𝑁) | 
| 22 | 19, 21 | eqtrd 2229 | 
. . . . . . . . . . . . . . . 16
⊢ ((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
→ (0 gcd 𝑁) = 𝑁) | 
| 23 | 22 | eqeq1d 2205 | 
. . . . . . . . . . . . . . 15
⊢ ((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
→ ((0 gcd 𝑁) = 1
↔ 𝑁 =
1)) | 
| 24 |   | lgs1 15285 | 
. . . . . . . . . . . . . . . . 17
⊢ (𝑥 ∈ ℤ → (𝑥 /L 1) =
1) | 
| 25 | 24 | adantl 277 | 
. . . . . . . . . . . . . . . 16
⊢ ((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
→ (𝑥
/L 1) = 1) | 
| 26 |   | oveq2 5930 | 
. . . . . . . . . . . . . . . . 17
⊢ (𝑁 = 1 → (𝑥 /L 𝑁) = (𝑥 /L 1)) | 
| 27 | 26 | eqeq1d 2205 | 
. . . . . . . . . . . . . . . 16
⊢ (𝑁 = 1 → ((𝑥 /L 𝑁) = 1 ↔ (𝑥 /L 1) =
1)) | 
| 28 | 25, 27 | syl5ibrcom 157 | 
. . . . . . . . . . . . . . 15
⊢ ((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
→ (𝑁 = 1 → (𝑥 /L 𝑁) = 1)) | 
| 29 | 23, 28 | sylbid 150 | 
. . . . . . . . . . . . . 14
⊢ ((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
→ ((0 gcd 𝑁) = 1
→ (𝑥
/L 𝑁) =
1)) | 
| 30 | 17, 29 | sylbid 150 | 
. . . . . . . . . . . . 13
⊢ ((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
→ ((0 /L 𝑁) ≠ 0 → (𝑥 /L 𝑁) = 1)) | 
| 31 | 30 | imp 124 | 
. . . . . . . . . . . 12
⊢ (((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
∧ (0 /L 𝑁) ≠ 0) → (𝑥 /L 𝑁) = 1) | 
| 32 | 31 | oveq1d 5937 | 
. . . . . . . . . . 11
⊢ (((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
∧ (0 /L 𝑁) ≠ 0) → ((𝑥 /L 𝑁) · (0 /L 𝑁)) = (1 · (0
/L 𝑁))) | 
| 33 | 5 | ad2antrr 488 | 
. . . . . . . . . . . . . 14
⊢ (((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
∧ (0 /L 𝑁) ≠ 0) → 𝑁 ∈ ℤ) | 
| 34 |   | lgscl 15255 | 
. . . . . . . . . . . . . 14
⊢ ((0
∈ ℤ ∧ 𝑁
∈ ℤ) → (0 /L 𝑁) ∈ ℤ) | 
| 35 | 14, 33, 34 | sylancr 414 | 
. . . . . . . . . . . . 13
⊢ (((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
∧ (0 /L 𝑁) ≠ 0) → (0 /L
𝑁) ∈
ℤ) | 
| 36 | 35 | zcnd 9449 | 
. . . . . . . . . . . 12
⊢ (((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
∧ (0 /L 𝑁) ≠ 0) → (0 /L
𝑁) ∈
ℂ) | 
| 37 | 36 | mulid2d 8045 | 
. . . . . . . . . . 11
⊢ (((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
∧ (0 /L 𝑁) ≠ 0) → (1 · (0
/L 𝑁)) =
(0 /L 𝑁)) | 
| 38 | 32, 37 | eqtr2d 2230 | 
. . . . . . . . . 10
⊢ (((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
∧ (0 /L 𝑁) ≠ 0) → (0 /L
𝑁) = ((𝑥 /L 𝑁) · (0 /L 𝑁))) | 
| 39 | 14, 15, 34 | sylancr 414 | 
. . . . . . . . . . . 12
⊢ ((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
→ (0 /L 𝑁) ∈ ℤ) | 
| 40 |   | zdceq 9401 | 
. . . . . . . . . . . 12
⊢ (((0
/L 𝑁)
∈ ℤ ∧ 0 ∈ ℤ) → DECID (0
/L 𝑁) =
0) | 
| 41 | 39, 14, 40 | sylancl 413 | 
. . . . . . . . . . 11
⊢ ((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
→ DECID (0 /L 𝑁) = 0) | 
| 42 |   | dcne 2378 | 
. . . . . . . . . . 11
⊢
(DECID (0 /L 𝑁) = 0 ↔ ((0 /L 𝑁) = 0 ∨ (0
/L 𝑁)
≠ 0)) | 
| 43 | 41, 42 | sylib 122 | 
. . . . . . . . . 10
⊢ ((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
→ ((0 /L 𝑁) = 0 ∨ (0 /L 𝑁) ≠ 0)) | 
| 44 | 13, 38, 43 | mpjaodan 799 | 
. . . . . . . . 9
⊢ ((𝑁 ∈ ℕ0
∧ 𝑥 ∈ ℤ)
→ (0 /L 𝑁) = ((𝑥 /L 𝑁) · (0 /L 𝑁))) | 
| 45 | 44 | ralrimiva 2570 | 
. . . . . . . 8
⊢ (𝑁 ∈ ℕ0
→ ∀𝑥 ∈
ℤ (0 /L 𝑁) = ((𝑥 /L 𝑁) · (0 /L 𝑁))) | 
| 46 | 45 | 3ad2ant3 1022 | 
. . . . . . 7
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ ∀𝑥 ∈
ℤ (0 /L 𝑁) = ((𝑥 /L 𝑁) · (0 /L 𝑁))) | 
| 47 |   | simp2 1000 | 
. . . . . . 7
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ 𝐵 ∈
ℤ) | 
| 48 | 3, 46, 47 | rspcdva 2873 | 
. . . . . 6
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ (0 /L 𝑁) = ((𝐵 /L 𝑁) · (0 /L 𝑁))) | 
| 49 | 48 | adantr 276 | 
. . . . 5
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐴 = 0) → (0
/L 𝑁) =
((𝐵 /L
𝑁) · (0
/L 𝑁))) | 
| 50 | 5 | 3ad2ant3 1022 | 
. . . . . . . . 9
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ 𝑁 ∈
ℤ) | 
| 51 | 14, 50, 34 | sylancr 414 | 
. . . . . . . 8
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ (0 /L 𝑁) ∈ ℤ) | 
| 52 | 51 | zcnd 9449 | 
. . . . . . 7
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ (0 /L 𝑁) ∈ ℂ) | 
| 53 | 52 | adantr 276 | 
. . . . . 6
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐴 = 0) → (0
/L 𝑁)
∈ ℂ) | 
| 54 |   | lgscl 15255 | 
. . . . . . . . 9
⊢ ((𝐵 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝐵 /L 𝑁) ∈
ℤ) | 
| 55 | 47, 50, 54 | syl2anc 411 | 
. . . . . . . 8
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ (𝐵
/L 𝑁)
∈ ℤ) | 
| 56 | 55 | zcnd 9449 | 
. . . . . . 7
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ (𝐵
/L 𝑁)
∈ ℂ) | 
| 57 | 56 | adantr 276 | 
. . . . . 6
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐴 = 0) → (𝐵 /L 𝑁) ∈
ℂ) | 
| 58 | 53, 57 | mulcomd 8048 | 
. . . . 5
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐴 = 0) → ((0
/L 𝑁)
· (𝐵
/L 𝑁)) =
((𝐵 /L
𝑁) · (0
/L 𝑁))) | 
| 59 | 49, 58 | eqtr4d 2232 | 
. . . 4
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐴 = 0) → (0
/L 𝑁) =
((0 /L 𝑁)
· (𝐵
/L 𝑁))) | 
| 60 |   | oveq1 5929 | 
. . . . . 6
⊢ (𝐴 = 0 → (𝐴 · 𝐵) = (0 · 𝐵)) | 
| 61 |   | zcn 9331 | 
. . . . . . . 8
⊢ (𝐵 ∈ ℤ → 𝐵 ∈
ℂ) | 
| 62 | 61 | 3ad2ant2 1021 | 
. . . . . . 7
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ 𝐵 ∈
ℂ) | 
| 63 | 62 | mul02d 8418 | 
. . . . . 6
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ (0 · 𝐵) =
0) | 
| 64 | 60, 63 | sylan9eqr 2251 | 
. . . . 5
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐴 = 0) → (𝐴 · 𝐵) = 0) | 
| 65 | 64 | oveq1d 5937 | 
. . . 4
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐴 = 0) → ((𝐴 · 𝐵) /L 𝑁) = (0 /L 𝑁)) | 
| 66 |   | simpr 110 | 
. . . . . 6
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐴 = 0) → 𝐴 = 0) | 
| 67 | 66 | oveq1d 5937 | 
. . . . 5
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐴 = 0) → (𝐴 /L 𝑁) = (0 /L
𝑁)) | 
| 68 | 67 | oveq1d 5937 | 
. . . 4
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐴 = 0) → ((𝐴 /L 𝑁) · (𝐵 /L 𝑁)) = ((0 /L 𝑁) · (𝐵 /L 𝑁))) | 
| 69 | 59, 65, 68 | 3eqtr4d 2239 | 
. . 3
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐴 = 0) → ((𝐴 · 𝐵) /L 𝑁) = ((𝐴 /L 𝑁) · (𝐵 /L 𝑁))) | 
| 70 |   | oveq1 5929 | 
. . . . . . . 8
⊢ (𝑥 = 𝐴 → (𝑥 /L 𝑁) = (𝐴 /L 𝑁)) | 
| 71 | 70 | oveq1d 5937 | 
. . . . . . 7
⊢ (𝑥 = 𝐴 → ((𝑥 /L 𝑁) · (0 /L 𝑁)) = ((𝐴 /L 𝑁) · (0 /L 𝑁))) | 
| 72 | 71 | eqeq2d 2208 | 
. . . . . 6
⊢ (𝑥 = 𝐴 → ((0 /L 𝑁) = ((𝑥 /L 𝑁) · (0 /L 𝑁)) ↔ (0
/L 𝑁) =
((𝐴 /L
𝑁) · (0
/L 𝑁)))) | 
| 73 |   | simp1 999 | 
. . . . . 6
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ 𝐴 ∈
ℤ) | 
| 74 | 72, 46, 73 | rspcdva 2873 | 
. . . . 5
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ (0 /L 𝑁) = ((𝐴 /L 𝑁) · (0 /L 𝑁))) | 
| 75 | 74 | adantr 276 | 
. . . 4
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐵 = 0) → (0
/L 𝑁) =
((𝐴 /L
𝑁) · (0
/L 𝑁))) | 
| 76 |   | oveq2 5930 | 
. . . . . 6
⊢ (𝐵 = 0 → (𝐴 · 𝐵) = (𝐴 · 0)) | 
| 77 | 73 | zcnd 9449 | 
. . . . . . 7
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ 𝐴 ∈
ℂ) | 
| 78 | 77 | mul01d 8419 | 
. . . . . 6
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ (𝐴 · 0) =
0) | 
| 79 | 76, 78 | sylan9eqr 2251 | 
. . . . 5
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐵 = 0) → (𝐴 · 𝐵) = 0) | 
| 80 | 79 | oveq1d 5937 | 
. . . 4
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐵 = 0) → ((𝐴 · 𝐵) /L 𝑁) = (0 /L 𝑁)) | 
| 81 |   | simpr 110 | 
. . . . . 6
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐵 = 0) → 𝐵 = 0) | 
| 82 | 81 | oveq1d 5937 | 
. . . . 5
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐵 = 0) → (𝐵 /L 𝑁) = (0 /L
𝑁)) | 
| 83 | 82 | oveq2d 5938 | 
. . . 4
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐵 = 0) → ((𝐴 /L 𝑁) · (𝐵 /L 𝑁)) = ((𝐴 /L 𝑁) · (0 /L 𝑁))) | 
| 84 | 75, 80, 83 | 3eqtr4d 2239 | 
. . 3
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ 𝐵 = 0) → ((𝐴 · 𝐵) /L 𝑁) = ((𝐴 /L 𝑁) · (𝐵 /L 𝑁))) | 
| 85 | 69, 84 | jaodan 798 | 
. 2
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ (𝐴 = 0 ∨ 𝐵 = 0)) → ((𝐴 · 𝐵) /L 𝑁) = ((𝐴 /L 𝑁) · (𝐵 /L 𝑁))) | 
| 86 |   | neanior 2454 | 
. . 3
⊢ ((𝐴 ≠ 0 ∧ 𝐵 ≠ 0) ↔ ¬ (𝐴 = 0 ∨ 𝐵 = 0)) | 
| 87 |   | lgsdir 15276 | 
. . . 4
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ (𝐴 ≠ 0 ∧ 𝐵 ≠ 0)) → ((𝐴 · 𝐵) /L 𝑁) = ((𝐴 /L 𝑁) · (𝐵 /L 𝑁))) | 
| 88 | 5, 87 | syl3anl3 1299 | 
. . 3
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ (𝐴 ≠ 0 ∧ 𝐵 ≠ 0)) → ((𝐴 · 𝐵) /L 𝑁) = ((𝐴 /L 𝑁) · (𝐵 /L 𝑁))) | 
| 89 | 86, 88 | sylan2br 288 | 
. 2
⊢ (((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
∧ ¬ (𝐴 = 0 ∨
𝐵 = 0)) → ((𝐴 · 𝐵) /L 𝑁) = ((𝐴 /L 𝑁) · (𝐵 /L 𝑁))) | 
| 90 |   | zdceq 9401 | 
. . . . 5
⊢ ((𝐴 ∈ ℤ ∧ 0 ∈
ℤ) → DECID 𝐴 = 0) | 
| 91 | 73, 14, 90 | sylancl 413 | 
. . . 4
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ DECID 𝐴 = 0) | 
| 92 |   | zdceq 9401 | 
. . . . 5
⊢ ((𝐵 ∈ ℤ ∧ 0 ∈
ℤ) → DECID 𝐵 = 0) | 
| 93 | 47, 14, 92 | sylancl 413 | 
. . . 4
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ DECID 𝐵 = 0) | 
| 94 |   | dcor 937 | 
. . . 4
⊢
(DECID 𝐴 = 0 → (DECID 𝐵 = 0 → DECID
(𝐴 = 0 ∨ 𝐵 = 0))) | 
| 95 | 91, 93, 94 | sylc 62 | 
. . 3
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ DECID (𝐴 = 0 ∨ 𝐵 = 0)) | 
| 96 |   | exmiddc 837 | 
. . 3
⊢
(DECID (𝐴 = 0 ∨ 𝐵 = 0) → ((𝐴 = 0 ∨ 𝐵 = 0) ∨ ¬ (𝐴 = 0 ∨ 𝐵 = 0))) | 
| 97 | 95, 96 | syl 14 | 
. 2
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ ((𝐴 = 0 ∨ 𝐵 = 0) ∨ ¬ (𝐴 = 0 ∨ 𝐵 = 0))) | 
| 98 | 85, 89, 97 | mpjaodan 799 | 
1
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ0)
→ ((𝐴 · 𝐵) /L 𝑁) = ((𝐴 /L 𝑁) · (𝐵 /L 𝑁))) |