Step | Hyp | Ref
| Expression |
1 | | nzss.m |
. 2
⊢ (𝜑 → 𝑀 ∈ ℤ) |
2 | | nzss.n |
. 2
⊢ (𝜑 → 𝑁 ∈ 𝑉) |
3 | | iddvds 15960 |
. . . . . . . . 9
⊢ (𝑀 ∈ ℤ → 𝑀 ∥ 𝑀) |
4 | | breq2 5082 |
. . . . . . . . . 10
⊢ (𝑥 = 𝑀 → (𝑀 ∥ 𝑥 ↔ 𝑀 ∥ 𝑀)) |
5 | 4 | elabg 3608 |
. . . . . . . . 9
⊢ (𝑀 ∈ ℤ → (𝑀 ∈ {𝑥 ∣ 𝑀 ∥ 𝑥} ↔ 𝑀 ∥ 𝑀)) |
6 | 3, 5 | mpbird 256 |
. . . . . . . 8
⊢ (𝑀 ∈ ℤ → 𝑀 ∈ {𝑥 ∣ 𝑀 ∥ 𝑥}) |
7 | | reldvds 41886 |
. . . . . . . . 9
⊢ Rel
∥ |
8 | | relimasn 5989 |
. . . . . . . . 9
⊢ (Rel
∥ → ( ∥ “ {𝑀}) = {𝑥 ∣ 𝑀 ∥ 𝑥}) |
9 | 7, 8 | ax-mp 5 |
. . . . . . . 8
⊢ ( ∥
“ {𝑀}) = {𝑥 ∣ 𝑀 ∥ 𝑥} |
10 | 6, 9 | eleqtrrdi 2851 |
. . . . . . 7
⊢ (𝑀 ∈ ℤ → 𝑀 ∈ ( ∥ “ {𝑀})) |
11 | | ssel 3918 |
. . . . . . 7
⊢ ((
∥ “ {𝑀})
⊆ ( ∥ “ {𝑁}) → (𝑀 ∈ ( ∥ “ {𝑀}) → 𝑀 ∈ ( ∥ “ {𝑁}))) |
12 | 10, 11 | syl5 34 |
. . . . . 6
⊢ ((
∥ “ {𝑀})
⊆ ( ∥ “ {𝑁}) → (𝑀 ∈ ℤ → 𝑀 ∈ ( ∥ “ {𝑁}))) |
13 | | breq2 5082 |
. . . . . . 7
⊢ (𝑥 = 𝑀 → (𝑁 ∥ 𝑥 ↔ 𝑁 ∥ 𝑀)) |
14 | | relimasn 5989 |
. . . . . . . 8
⊢ (Rel
∥ → ( ∥ “ {𝑁}) = {𝑥 ∣ 𝑁 ∥ 𝑥}) |
15 | 7, 14 | ax-mp 5 |
. . . . . . 7
⊢ ( ∥
“ {𝑁}) = {𝑥 ∣ 𝑁 ∥ 𝑥} |
16 | 13, 15 | elab2g 3612 |
. . . . . 6
⊢ (𝑀 ∈ ℤ → (𝑀 ∈ ( ∥ “ {𝑁}) ↔ 𝑁 ∥ 𝑀)) |
17 | 12, 16 | mpbidi 240 |
. . . . 5
⊢ ((
∥ “ {𝑀})
⊆ ( ∥ “ {𝑁}) → (𝑀 ∈ ℤ → 𝑁 ∥ 𝑀)) |
18 | 17 | com12 32 |
. . . 4
⊢ (𝑀 ∈ ℤ → ((
∥ “ {𝑀})
⊆ ( ∥ “ {𝑁}) → 𝑁 ∥ 𝑀)) |
19 | 18 | adantr 480 |
. . 3
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ 𝑉) → (( ∥ “ {𝑀}) ⊆ ( ∥ “
{𝑁}) → 𝑁 ∥ 𝑀)) |
20 | | ssid 3947 |
. . . . . . 7
⊢ {0}
⊆ {0} |
21 | | simpl 482 |
. . . . . . . . . . . . 13
⊢ ((𝑁 ∥ 𝑀 ∧ 𝑁 = 0) → 𝑁 ∥ 𝑀) |
22 | | breq1 5081 |
. . . . . . . . . . . . . 14
⊢ (𝑁 = 0 → (𝑁 ∥ 𝑀 ↔ 0 ∥ 𝑀)) |
23 | | dvdszrcl 15949 |
. . . . . . . . . . . . . . . 16
⊢ (𝑁 ∥ 𝑀 → (𝑁 ∈ ℤ ∧ 𝑀 ∈ ℤ)) |
24 | 23 | simprd 495 |
. . . . . . . . . . . . . . 15
⊢ (𝑁 ∥ 𝑀 → 𝑀 ∈ ℤ) |
25 | | 0dvds 15967 |
. . . . . . . . . . . . . . 15
⊢ (𝑀 ∈ ℤ → (0
∥ 𝑀 ↔ 𝑀 = 0)) |
26 | 24, 25 | syl 17 |
. . . . . . . . . . . . . 14
⊢ (𝑁 ∥ 𝑀 → (0 ∥ 𝑀 ↔ 𝑀 = 0)) |
27 | 22, 26 | sylan9bbr 510 |
. . . . . . . . . . . . 13
⊢ ((𝑁 ∥ 𝑀 ∧ 𝑁 = 0) → (𝑁 ∥ 𝑀 ↔ 𝑀 = 0)) |
28 | 21, 27 | mpbid 231 |
. . . . . . . . . . . 12
⊢ ((𝑁 ∥ 𝑀 ∧ 𝑁 = 0) → 𝑀 = 0) |
29 | 28 | breq1d 5088 |
. . . . . . . . . . 11
⊢ ((𝑁 ∥ 𝑀 ∧ 𝑁 = 0) → (𝑀 ∥ 𝑥 ↔ 0 ∥ 𝑥)) |
30 | | 0dvds 15967 |
. . . . . . . . . . 11
⊢ (𝑥 ∈ ℤ → (0
∥ 𝑥 ↔ 𝑥 = 0)) |
31 | 29, 30 | sylan9bb 509 |
. . . . . . . . . 10
⊢ (((𝑁 ∥ 𝑀 ∧ 𝑁 = 0) ∧ 𝑥 ∈ ℤ) → (𝑀 ∥ 𝑥 ↔ 𝑥 = 0)) |
32 | 31 | rabbidva 3410 |
. . . . . . . . 9
⊢ ((𝑁 ∥ 𝑀 ∧ 𝑁 = 0) → {𝑥 ∈ ℤ ∣ 𝑀 ∥ 𝑥} = {𝑥 ∈ ℤ ∣ 𝑥 = 0}) |
33 | | 0z 12313 |
. . . . . . . . . 10
⊢ 0 ∈
ℤ |
34 | | rabsn 4662 |
. . . . . . . . . 10
⊢ (0 ∈
ℤ → {𝑥 ∈
ℤ ∣ 𝑥 = 0} =
{0}) |
35 | 33, 34 | ax-mp 5 |
. . . . . . . . 9
⊢ {𝑥 ∈ ℤ ∣ 𝑥 = 0} = {0} |
36 | 32, 35 | eqtrdi 2795 |
. . . . . . . 8
⊢ ((𝑁 ∥ 𝑀 ∧ 𝑁 = 0) → {𝑥 ∈ ℤ ∣ 𝑀 ∥ 𝑥} = {0}) |
37 | | breq1 5081 |
. . . . . . . . . . 11
⊢ (𝑁 = 0 → (𝑁 ∥ 𝑥 ↔ 0 ∥ 𝑥)) |
38 | 37 | rabbidv 3412 |
. . . . . . . . . 10
⊢ (𝑁 = 0 → {𝑥 ∈ ℤ ∣ 𝑁 ∥ 𝑥} = {𝑥 ∈ ℤ ∣ 0 ∥ 𝑥}) |
39 | 30 | rabbiia 3404 |
. . . . . . . . . . 11
⊢ {𝑥 ∈ ℤ ∣ 0
∥ 𝑥} = {𝑥 ∈ ℤ ∣ 𝑥 = 0} |
40 | 39, 35 | eqtri 2767 |
. . . . . . . . . 10
⊢ {𝑥 ∈ ℤ ∣ 0
∥ 𝑥} =
{0} |
41 | 38, 40 | eqtrdi 2795 |
. . . . . . . . 9
⊢ (𝑁 = 0 → {𝑥 ∈ ℤ ∣ 𝑁 ∥ 𝑥} = {0}) |
42 | 41 | adantl 481 |
. . . . . . . 8
⊢ ((𝑁 ∥ 𝑀 ∧ 𝑁 = 0) → {𝑥 ∈ ℤ ∣ 𝑁 ∥ 𝑥} = {0}) |
43 | 36, 42 | sseq12d 3958 |
. . . . . . 7
⊢ ((𝑁 ∥ 𝑀 ∧ 𝑁 = 0) → ({𝑥 ∈ ℤ ∣ 𝑀 ∥ 𝑥} ⊆ {𝑥 ∈ ℤ ∣ 𝑁 ∥ 𝑥} ↔ {0} ⊆ {0})) |
44 | 20, 43 | mpbiri 257 |
. . . . . 6
⊢ ((𝑁 ∥ 𝑀 ∧ 𝑁 = 0) → {𝑥 ∈ ℤ ∣ 𝑀 ∥ 𝑥} ⊆ {𝑥 ∈ ℤ ∣ 𝑁 ∥ 𝑥}) |
45 | 24 | zcnd 12409 |
. . . . . . . . . . . 12
⊢ (𝑁 ∥ 𝑀 → 𝑀 ∈ ℂ) |
46 | 45 | ad2antrr 722 |
. . . . . . . . . . 11
⊢ (((𝑁 ∥ 𝑀 ∧ 𝑁 ≠ 0) ∧ 𝑛 ∈ ℤ) → 𝑀 ∈ ℂ) |
47 | 23 | simpld 494 |
. . . . . . . . . . . . 13
⊢ (𝑁 ∥ 𝑀 → 𝑁 ∈ ℤ) |
48 | 47 | zcnd 12409 |
. . . . . . . . . . . 12
⊢ (𝑁 ∥ 𝑀 → 𝑁 ∈ ℂ) |
49 | 48 | ad2antrr 722 |
. . . . . . . . . . 11
⊢ (((𝑁 ∥ 𝑀 ∧ 𝑁 ≠ 0) ∧ 𝑛 ∈ ℤ) → 𝑁 ∈ ℂ) |
50 | | simplr 765 |
. . . . . . . . . . 11
⊢ (((𝑁 ∥ 𝑀 ∧ 𝑁 ≠ 0) ∧ 𝑛 ∈ ℤ) → 𝑁 ≠ 0) |
51 | 46, 49, 50 | divcan2d 11736 |
. . . . . . . . . 10
⊢ (((𝑁 ∥ 𝑀 ∧ 𝑁 ≠ 0) ∧ 𝑛 ∈ ℤ) → (𝑁 · (𝑀 / 𝑁)) = 𝑀) |
52 | 51 | breq1d 5088 |
. . . . . . . . 9
⊢ (((𝑁 ∥ 𝑀 ∧ 𝑁 ≠ 0) ∧ 𝑛 ∈ ℤ) → ((𝑁 · (𝑀 / 𝑁)) ∥ 𝑛 ↔ 𝑀 ∥ 𝑛)) |
53 | 47 | adantr 480 |
. . . . . . . . . . 11
⊢ ((𝑁 ∥ 𝑀 ∧ 𝑁 ≠ 0) → 𝑁 ∈ ℤ) |
54 | | dvdsval2 15947 |
. . . . . . . . . . . . . . . . 17
⊢ ((𝑁 ∈ ℤ ∧ 𝑁 ≠ 0 ∧ 𝑀 ∈ ℤ) → (𝑁 ∥ 𝑀 ↔ (𝑀 / 𝑁) ∈ ℤ)) |
55 | 54 | biimpd 228 |
. . . . . . . . . . . . . . . 16
⊢ ((𝑁 ∈ ℤ ∧ 𝑁 ≠ 0 ∧ 𝑀 ∈ ℤ) → (𝑁 ∥ 𝑀 → (𝑀 / 𝑁) ∈ ℤ)) |
56 | 55 | 3com23 1124 |
. . . . . . . . . . . . . . 15
⊢ ((𝑁 ∈ ℤ ∧ 𝑀 ∈ ℤ ∧ 𝑁 ≠ 0) → (𝑁 ∥ 𝑀 → (𝑀 / 𝑁) ∈ ℤ)) |
57 | 56 | 3expa 1116 |
. . . . . . . . . . . . . 14
⊢ (((𝑁 ∈ ℤ ∧ 𝑀 ∈ ℤ) ∧ 𝑁 ≠ 0) → (𝑁 ∥ 𝑀 → (𝑀 / 𝑁) ∈ ℤ)) |
58 | 23, 57 | sylan 579 |
. . . . . . . . . . . . 13
⊢ ((𝑁 ∥ 𝑀 ∧ 𝑁 ≠ 0) → (𝑁 ∥ 𝑀 → (𝑀 / 𝑁) ∈ ℤ)) |
59 | 58 | imp 406 |
. . . . . . . . . . . 12
⊢ (((𝑁 ∥ 𝑀 ∧ 𝑁 ≠ 0) ∧ 𝑁 ∥ 𝑀) → (𝑀 / 𝑁) ∈ ℤ) |
60 | 59 | anabss1 662 |
. . . . . . . . . . 11
⊢ ((𝑁 ∥ 𝑀 ∧ 𝑁 ≠ 0) → (𝑀 / 𝑁) ∈ ℤ) |
61 | 53, 60 | jca 511 |
. . . . . . . . . 10
⊢ ((𝑁 ∥ 𝑀 ∧ 𝑁 ≠ 0) → (𝑁 ∈ ℤ ∧ (𝑀 / 𝑁) ∈ ℤ)) |
62 | | muldvds1 15971 |
. . . . . . . . . . 11
⊢ ((𝑁 ∈ ℤ ∧ (𝑀 / 𝑁) ∈ ℤ ∧ 𝑛 ∈ ℤ) → ((𝑁 · (𝑀 / 𝑁)) ∥ 𝑛 → 𝑁 ∥ 𝑛)) |
63 | 62 | 3expa 1116 |
. . . . . . . . . 10
⊢ (((𝑁 ∈ ℤ ∧ (𝑀 / 𝑁) ∈ ℤ) ∧ 𝑛 ∈ ℤ) → ((𝑁 · (𝑀 / 𝑁)) ∥ 𝑛 → 𝑁 ∥ 𝑛)) |
64 | 61, 63 | sylan 579 |
. . . . . . . . 9
⊢ (((𝑁 ∥ 𝑀 ∧ 𝑁 ≠ 0) ∧ 𝑛 ∈ ℤ) → ((𝑁 · (𝑀 / 𝑁)) ∥ 𝑛 → 𝑁 ∥ 𝑛)) |
65 | 52, 64 | sylbird 259 |
. . . . . . . 8
⊢ (((𝑁 ∥ 𝑀 ∧ 𝑁 ≠ 0) ∧ 𝑛 ∈ ℤ) → (𝑀 ∥ 𝑛 → 𝑁 ∥ 𝑛)) |
66 | 65 | ss2rabdv 4013 |
. . . . . . 7
⊢ ((𝑁 ∥ 𝑀 ∧ 𝑁 ≠ 0) → {𝑛 ∈ ℤ ∣ 𝑀 ∥ 𝑛} ⊆ {𝑛 ∈ ℤ ∣ 𝑁 ∥ 𝑛}) |
67 | | breq2 5082 |
. . . . . . . 8
⊢ (𝑛 = 𝑥 → (𝑀 ∥ 𝑛 ↔ 𝑀 ∥ 𝑥)) |
68 | 67 | cbvrabv 3424 |
. . . . . . 7
⊢ {𝑛 ∈ ℤ ∣ 𝑀 ∥ 𝑛} = {𝑥 ∈ ℤ ∣ 𝑀 ∥ 𝑥} |
69 | | breq2 5082 |
. . . . . . . 8
⊢ (𝑛 = 𝑥 → (𝑁 ∥ 𝑛 ↔ 𝑁 ∥ 𝑥)) |
70 | 69 | cbvrabv 3424 |
. . . . . . 7
⊢ {𝑛 ∈ ℤ ∣ 𝑁 ∥ 𝑛} = {𝑥 ∈ ℤ ∣ 𝑁 ∥ 𝑥} |
71 | 66, 68, 70 | 3sstr3g 3969 |
. . . . . 6
⊢ ((𝑁 ∥ 𝑀 ∧ 𝑁 ≠ 0) → {𝑥 ∈ ℤ ∣ 𝑀 ∥ 𝑥} ⊆ {𝑥 ∈ ℤ ∣ 𝑁 ∥ 𝑥}) |
72 | 44, 71 | pm2.61dane 3033 |
. . . . 5
⊢ (𝑁 ∥ 𝑀 → {𝑥 ∈ ℤ ∣ 𝑀 ∥ 𝑥} ⊆ {𝑥 ∈ ℤ ∣ 𝑁 ∥ 𝑥}) |
73 | | breq1 5081 |
. . . . . . . . . 10
⊢ (𝑛 = 𝑀 → (𝑛 ∥ 𝑥 ↔ 𝑀 ∥ 𝑥)) |
74 | 73 | rabbidv 3412 |
. . . . . . . . 9
⊢ (𝑛 = 𝑀 → {𝑥 ∈ ℤ ∣ 𝑛 ∥ 𝑥} = {𝑥 ∈ ℤ ∣ 𝑀 ∥ 𝑥}) |
75 | 73 | abbidv 2808 |
. . . . . . . . 9
⊢ (𝑛 = 𝑀 → {𝑥 ∣ 𝑛 ∥ 𝑥} = {𝑥 ∣ 𝑀 ∥ 𝑥}) |
76 | 74, 75 | eqeq12d 2755 |
. . . . . . . 8
⊢ (𝑛 = 𝑀 → ({𝑥 ∈ ℤ ∣ 𝑛 ∥ 𝑥} = {𝑥 ∣ 𝑛 ∥ 𝑥} ↔ {𝑥 ∈ ℤ ∣ 𝑀 ∥ 𝑥} = {𝑥 ∣ 𝑀 ∥ 𝑥})) |
77 | | simpr 484 |
. . . . . . . . . . 11
⊢ ((𝑦 ∈ ℤ ∧ 𝑛 ∥ 𝑦) → 𝑛 ∥ 𝑦) |
78 | | dvdszrcl 15949 |
. . . . . . . . . . . . 13
⊢ (𝑛 ∥ 𝑦 → (𝑛 ∈ ℤ ∧ 𝑦 ∈ ℤ)) |
79 | 78 | simprd 495 |
. . . . . . . . . . . 12
⊢ (𝑛 ∥ 𝑦 → 𝑦 ∈ ℤ) |
80 | 79 | ancri 549 |
. . . . . . . . . . 11
⊢ (𝑛 ∥ 𝑦 → (𝑦 ∈ ℤ ∧ 𝑛 ∥ 𝑦)) |
81 | 77, 80 | impbii 208 |
. . . . . . . . . 10
⊢ ((𝑦 ∈ ℤ ∧ 𝑛 ∥ 𝑦) ↔ 𝑛 ∥ 𝑦) |
82 | | breq2 5082 |
. . . . . . . . . . 11
⊢ (𝑥 = 𝑦 → (𝑛 ∥ 𝑥 ↔ 𝑛 ∥ 𝑦)) |
83 | 82 | elrab 3625 |
. . . . . . . . . 10
⊢ (𝑦 ∈ {𝑥 ∈ ℤ ∣ 𝑛 ∥ 𝑥} ↔ (𝑦 ∈ ℤ ∧ 𝑛 ∥ 𝑦)) |
84 | | vex 3434 |
. . . . . . . . . . 11
⊢ 𝑦 ∈ V |
85 | 84, 82 | elab 3610 |
. . . . . . . . . 10
⊢ (𝑦 ∈ {𝑥 ∣ 𝑛 ∥ 𝑥} ↔ 𝑛 ∥ 𝑦) |
86 | 81, 83, 85 | 3bitr4i 302 |
. . . . . . . . 9
⊢ (𝑦 ∈ {𝑥 ∈ ℤ ∣ 𝑛 ∥ 𝑥} ↔ 𝑦 ∈ {𝑥 ∣ 𝑛 ∥ 𝑥}) |
87 | 86 | eqriv 2736 |
. . . . . . . 8
⊢ {𝑥 ∈ ℤ ∣ 𝑛 ∥ 𝑥} = {𝑥 ∣ 𝑛 ∥ 𝑥} |
88 | 76, 87 | vtoclg 3503 |
. . . . . . 7
⊢ (𝑀 ∈ ℤ → {𝑥 ∈ ℤ ∣ 𝑀 ∥ 𝑥} = {𝑥 ∣ 𝑀 ∥ 𝑥}) |
89 | 88 | adantr 480 |
. . . . . 6
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ 𝑉) → {𝑥 ∈ ℤ ∣ 𝑀 ∥ 𝑥} = {𝑥 ∣ 𝑀 ∥ 𝑥}) |
90 | | breq1 5081 |
. . . . . . . . . 10
⊢ (𝑛 = 𝑁 → (𝑛 ∥ 𝑥 ↔ 𝑁 ∥ 𝑥)) |
91 | 90 | rabbidv 3412 |
. . . . . . . . 9
⊢ (𝑛 = 𝑁 → {𝑥 ∈ ℤ ∣ 𝑛 ∥ 𝑥} = {𝑥 ∈ ℤ ∣ 𝑁 ∥ 𝑥}) |
92 | 90 | abbidv 2808 |
. . . . . . . . 9
⊢ (𝑛 = 𝑁 → {𝑥 ∣ 𝑛 ∥ 𝑥} = {𝑥 ∣ 𝑁 ∥ 𝑥}) |
93 | 91, 92 | eqeq12d 2755 |
. . . . . . . 8
⊢ (𝑛 = 𝑁 → ({𝑥 ∈ ℤ ∣ 𝑛 ∥ 𝑥} = {𝑥 ∣ 𝑛 ∥ 𝑥} ↔ {𝑥 ∈ ℤ ∣ 𝑁 ∥ 𝑥} = {𝑥 ∣ 𝑁 ∥ 𝑥})) |
94 | 93, 87 | vtoclg 3503 |
. . . . . . 7
⊢ (𝑁 ∈ 𝑉 → {𝑥 ∈ ℤ ∣ 𝑁 ∥ 𝑥} = {𝑥 ∣ 𝑁 ∥ 𝑥}) |
95 | 94 | adantl 481 |
. . . . . 6
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ 𝑉) → {𝑥 ∈ ℤ ∣ 𝑁 ∥ 𝑥} = {𝑥 ∣ 𝑁 ∥ 𝑥}) |
96 | 89, 95 | sseq12d 3958 |
. . . . 5
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ 𝑉) → ({𝑥 ∈ ℤ ∣ 𝑀 ∥ 𝑥} ⊆ {𝑥 ∈ ℤ ∣ 𝑁 ∥ 𝑥} ↔ {𝑥 ∣ 𝑀 ∥ 𝑥} ⊆ {𝑥 ∣ 𝑁 ∥ 𝑥})) |
97 | 72, 96 | syl5ib 243 |
. . . 4
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ 𝑉) → (𝑁 ∥ 𝑀 → {𝑥 ∣ 𝑀 ∥ 𝑥} ⊆ {𝑥 ∣ 𝑁 ∥ 𝑥})) |
98 | 9, 15 | sseq12i 3955 |
. . . 4
⊢ ((
∥ “ {𝑀})
⊆ ( ∥ “ {𝑁}) ↔ {𝑥 ∣ 𝑀 ∥ 𝑥} ⊆ {𝑥 ∣ 𝑁 ∥ 𝑥}) |
99 | 97, 98 | syl6ibr 251 |
. . 3
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ 𝑉) → (𝑁 ∥ 𝑀 → ( ∥ “ {𝑀}) ⊆ ( ∥ “ {𝑁}))) |
100 | 19, 99 | impbid 211 |
. 2
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ 𝑉) → (( ∥ “ {𝑀}) ⊆ ( ∥ “
{𝑁}) ↔ 𝑁 ∥ 𝑀)) |
101 | 1, 2, 100 | syl2anc 583 |
1
⊢ (𝜑 → (( ∥ “ {𝑀}) ⊆ ( ∥ “
{𝑁}) ↔ 𝑁 ∥ 𝑀)) |