Step |
Hyp |
Ref |
Expression |
1 |
|
2zrng.e |
⊢ 𝐸 = { 𝑧 ∈ ℤ ∣ ∃ 𝑥 ∈ ℤ 𝑧 = ( 2 · 𝑥 ) } |
2 |
|
2zrngbas.r |
⊢ 𝑅 = ( ℂfld ↾s 𝐸 ) |
3 |
|
eqeq1 |
⊢ ( 𝑧 = 𝑎 → ( 𝑧 = ( 2 · 𝑥 ) ↔ 𝑎 = ( 2 · 𝑥 ) ) ) |
4 |
3
|
rexbidv |
⊢ ( 𝑧 = 𝑎 → ( ∃ 𝑥 ∈ ℤ 𝑧 = ( 2 · 𝑥 ) ↔ ∃ 𝑥 ∈ ℤ 𝑎 = ( 2 · 𝑥 ) ) ) |
5 |
4 1
|
elrab2 |
⊢ ( 𝑎 ∈ 𝐸 ↔ ( 𝑎 ∈ ℤ ∧ ∃ 𝑥 ∈ ℤ 𝑎 = ( 2 · 𝑥 ) ) ) |
6 |
|
eqeq1 |
⊢ ( 𝑧 = 𝑏 → ( 𝑧 = ( 2 · 𝑥 ) ↔ 𝑏 = ( 2 · 𝑥 ) ) ) |
7 |
6
|
rexbidv |
⊢ ( 𝑧 = 𝑏 → ( ∃ 𝑥 ∈ ℤ 𝑧 = ( 2 · 𝑥 ) ↔ ∃ 𝑥 ∈ ℤ 𝑏 = ( 2 · 𝑥 ) ) ) |
8 |
7 1
|
elrab2 |
⊢ ( 𝑏 ∈ 𝐸 ↔ ( 𝑏 ∈ ℤ ∧ ∃ 𝑥 ∈ ℤ 𝑏 = ( 2 · 𝑥 ) ) ) |
9 |
|
oveq2 |
⊢ ( 𝑥 = 𝑦 → ( 2 · 𝑥 ) = ( 2 · 𝑦 ) ) |
10 |
9
|
eqeq2d |
⊢ ( 𝑥 = 𝑦 → ( 𝑎 = ( 2 · 𝑥 ) ↔ 𝑎 = ( 2 · 𝑦 ) ) ) |
11 |
10
|
cbvrexvw |
⊢ ( ∃ 𝑥 ∈ ℤ 𝑎 = ( 2 · 𝑥 ) ↔ ∃ 𝑦 ∈ ℤ 𝑎 = ( 2 · 𝑦 ) ) |
12 |
|
zaddcl |
⊢ ( ( 𝑎 ∈ ℤ ∧ 𝑏 ∈ ℤ ) → ( 𝑎 + 𝑏 ) ∈ ℤ ) |
13 |
12
|
ancoms |
⊢ ( ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) → ( 𝑎 + 𝑏 ) ∈ ℤ ) |
14 |
13
|
adantr |
⊢ ( ( ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) ∧ ( ∃ 𝑥 ∈ ℤ 𝑏 = ( 2 · 𝑥 ) ∧ ∃ 𝑦 ∈ ℤ 𝑎 = ( 2 · 𝑦 ) ) ) → ( 𝑎 + 𝑏 ) ∈ ℤ ) |
15 |
|
simpl |
⊢ ( ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) → 𝑦 ∈ ℤ ) |
16 |
|
simpl |
⊢ ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) → 𝑥 ∈ ℤ ) |
17 |
|
zaddcl |
⊢ ( ( 𝑦 ∈ ℤ ∧ 𝑥 ∈ ℤ ) → ( 𝑦 + 𝑥 ) ∈ ℤ ) |
18 |
15 16 17
|
syl2anr |
⊢ ( ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) ∧ ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) ) → ( 𝑦 + 𝑥 ) ∈ ℤ ) |
19 |
18
|
adantr |
⊢ ( ( ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) ∧ ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) ) ∧ ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) ) → ( 𝑦 + 𝑥 ) ∈ ℤ ) |
20 |
|
oveq2 |
⊢ ( 𝑧 = ( 𝑦 + 𝑥 ) → ( 2 · 𝑧 ) = ( 2 · ( 𝑦 + 𝑥 ) ) ) |
21 |
20
|
eqeq2d |
⊢ ( 𝑧 = ( 𝑦 + 𝑥 ) → ( ( 2 · ( 𝑦 + 𝑥 ) ) = ( 2 · 𝑧 ) ↔ ( 2 · ( 𝑦 + 𝑥 ) ) = ( 2 · ( 𝑦 + 𝑥 ) ) ) ) |
22 |
21
|
adantl |
⊢ ( ( ( ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) ∧ ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) ) ∧ ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) ) ∧ 𝑧 = ( 𝑦 + 𝑥 ) ) → ( ( 2 · ( 𝑦 + 𝑥 ) ) = ( 2 · 𝑧 ) ↔ ( 2 · ( 𝑦 + 𝑥 ) ) = ( 2 · ( 𝑦 + 𝑥 ) ) ) ) |
23 |
|
eqidd |
⊢ ( ( ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) ∧ ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) ) ∧ ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) ) → ( 2 · ( 𝑦 + 𝑥 ) ) = ( 2 · ( 𝑦 + 𝑥 ) ) ) |
24 |
19 22 23
|
rspcedvd |
⊢ ( ( ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) ∧ ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) ) ∧ ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) ) → ∃ 𝑧 ∈ ℤ ( 2 · ( 𝑦 + 𝑥 ) ) = ( 2 · 𝑧 ) ) |
25 |
|
simpr |
⊢ ( ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) → 𝑎 = ( 2 · 𝑦 ) ) |
26 |
|
simpr |
⊢ ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) → 𝑏 = ( 2 · 𝑥 ) ) |
27 |
25 26
|
oveqan12rd |
⊢ ( ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) ∧ ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) ) → ( 𝑎 + 𝑏 ) = ( ( 2 · 𝑦 ) + ( 2 · 𝑥 ) ) ) |
28 |
27
|
adantr |
⊢ ( ( ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) ∧ ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) ) ∧ ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) ) → ( 𝑎 + 𝑏 ) = ( ( 2 · 𝑦 ) + ( 2 · 𝑥 ) ) ) |
29 |
|
2cnd |
⊢ ( ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) ∧ ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) ) → 2 ∈ ℂ ) |
30 |
|
zcn |
⊢ ( 𝑦 ∈ ℤ → 𝑦 ∈ ℂ ) |
31 |
30
|
adantr |
⊢ ( ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) → 𝑦 ∈ ℂ ) |
32 |
31
|
adantl |
⊢ ( ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) ∧ ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) ) → 𝑦 ∈ ℂ ) |
33 |
|
zcn |
⊢ ( 𝑥 ∈ ℤ → 𝑥 ∈ ℂ ) |
34 |
33
|
adantr |
⊢ ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) → 𝑥 ∈ ℂ ) |
35 |
34
|
adantr |
⊢ ( ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) ∧ ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) ) → 𝑥 ∈ ℂ ) |
36 |
29 32 35
|
adddid |
⊢ ( ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) ∧ ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) ) → ( 2 · ( 𝑦 + 𝑥 ) ) = ( ( 2 · 𝑦 ) + ( 2 · 𝑥 ) ) ) |
37 |
36
|
adantr |
⊢ ( ( ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) ∧ ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) ) ∧ ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) ) → ( 2 · ( 𝑦 + 𝑥 ) ) = ( ( 2 · 𝑦 ) + ( 2 · 𝑥 ) ) ) |
38 |
28 37
|
eqtr4d |
⊢ ( ( ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) ∧ ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) ) ∧ ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) ) → ( 𝑎 + 𝑏 ) = ( 2 · ( 𝑦 + 𝑥 ) ) ) |
39 |
38
|
eqeq1d |
⊢ ( ( ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) ∧ ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) ) ∧ ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) ) → ( ( 𝑎 + 𝑏 ) = ( 2 · 𝑧 ) ↔ ( 2 · ( 𝑦 + 𝑥 ) ) = ( 2 · 𝑧 ) ) ) |
40 |
39
|
rexbidv |
⊢ ( ( ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) ∧ ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) ) ∧ ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) ) → ( ∃ 𝑧 ∈ ℤ ( 𝑎 + 𝑏 ) = ( 2 · 𝑧 ) ↔ ∃ 𝑧 ∈ ℤ ( 2 · ( 𝑦 + 𝑥 ) ) = ( 2 · 𝑧 ) ) ) |
41 |
24 40
|
mpbird |
⊢ ( ( ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) ∧ ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) ) ∧ ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) ) → ∃ 𝑧 ∈ ℤ ( 𝑎 + 𝑏 ) = ( 2 · 𝑧 ) ) |
42 |
41
|
ex |
⊢ ( ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) ∧ ( 𝑦 ∈ ℤ ∧ 𝑎 = ( 2 · 𝑦 ) ) ) → ( ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) → ∃ 𝑧 ∈ ℤ ( 𝑎 + 𝑏 ) = ( 2 · 𝑧 ) ) ) |
43 |
42
|
rexlimdvaa |
⊢ ( ( 𝑥 ∈ ℤ ∧ 𝑏 = ( 2 · 𝑥 ) ) → ( ∃ 𝑦 ∈ ℤ 𝑎 = ( 2 · 𝑦 ) → ( ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) → ∃ 𝑧 ∈ ℤ ( 𝑎 + 𝑏 ) = ( 2 · 𝑧 ) ) ) ) |
44 |
43
|
rexlimiva |
⊢ ( ∃ 𝑥 ∈ ℤ 𝑏 = ( 2 · 𝑥 ) → ( ∃ 𝑦 ∈ ℤ 𝑎 = ( 2 · 𝑦 ) → ( ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) → ∃ 𝑧 ∈ ℤ ( 𝑎 + 𝑏 ) = ( 2 · 𝑧 ) ) ) ) |
45 |
44
|
imp |
⊢ ( ( ∃ 𝑥 ∈ ℤ 𝑏 = ( 2 · 𝑥 ) ∧ ∃ 𝑦 ∈ ℤ 𝑎 = ( 2 · 𝑦 ) ) → ( ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) → ∃ 𝑧 ∈ ℤ ( 𝑎 + 𝑏 ) = ( 2 · 𝑧 ) ) ) |
46 |
|
oveq2 |
⊢ ( 𝑥 = 𝑧 → ( 2 · 𝑥 ) = ( 2 · 𝑧 ) ) |
47 |
46
|
eqeq2d |
⊢ ( 𝑥 = 𝑧 → ( ( 𝑎 + 𝑏 ) = ( 2 · 𝑥 ) ↔ ( 𝑎 + 𝑏 ) = ( 2 · 𝑧 ) ) ) |
48 |
47
|
cbvrexvw |
⊢ ( ∃ 𝑥 ∈ ℤ ( 𝑎 + 𝑏 ) = ( 2 · 𝑥 ) ↔ ∃ 𝑧 ∈ ℤ ( 𝑎 + 𝑏 ) = ( 2 · 𝑧 ) ) |
49 |
45 48
|
syl6ibr |
⊢ ( ( ∃ 𝑥 ∈ ℤ 𝑏 = ( 2 · 𝑥 ) ∧ ∃ 𝑦 ∈ ℤ 𝑎 = ( 2 · 𝑦 ) ) → ( ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) → ∃ 𝑥 ∈ ℤ ( 𝑎 + 𝑏 ) = ( 2 · 𝑥 ) ) ) |
50 |
49
|
impcom |
⊢ ( ( ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) ∧ ( ∃ 𝑥 ∈ ℤ 𝑏 = ( 2 · 𝑥 ) ∧ ∃ 𝑦 ∈ ℤ 𝑎 = ( 2 · 𝑦 ) ) ) → ∃ 𝑥 ∈ ℤ ( 𝑎 + 𝑏 ) = ( 2 · 𝑥 ) ) |
51 |
|
eqeq1 |
⊢ ( 𝑧 = ( 𝑎 + 𝑏 ) → ( 𝑧 = ( 2 · 𝑥 ) ↔ ( 𝑎 + 𝑏 ) = ( 2 · 𝑥 ) ) ) |
52 |
51
|
rexbidv |
⊢ ( 𝑧 = ( 𝑎 + 𝑏 ) → ( ∃ 𝑥 ∈ ℤ 𝑧 = ( 2 · 𝑥 ) ↔ ∃ 𝑥 ∈ ℤ ( 𝑎 + 𝑏 ) = ( 2 · 𝑥 ) ) ) |
53 |
52 1
|
elrab2 |
⊢ ( ( 𝑎 + 𝑏 ) ∈ 𝐸 ↔ ( ( 𝑎 + 𝑏 ) ∈ ℤ ∧ ∃ 𝑥 ∈ ℤ ( 𝑎 + 𝑏 ) = ( 2 · 𝑥 ) ) ) |
54 |
14 50 53
|
sylanbrc |
⊢ ( ( ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) ∧ ( ∃ 𝑥 ∈ ℤ 𝑏 = ( 2 · 𝑥 ) ∧ ∃ 𝑦 ∈ ℤ 𝑎 = ( 2 · 𝑦 ) ) ) → ( 𝑎 + 𝑏 ) ∈ 𝐸 ) |
55 |
54
|
exp32 |
⊢ ( ( 𝑏 ∈ ℤ ∧ 𝑎 ∈ ℤ ) → ( ∃ 𝑥 ∈ ℤ 𝑏 = ( 2 · 𝑥 ) → ( ∃ 𝑦 ∈ ℤ 𝑎 = ( 2 · 𝑦 ) → ( 𝑎 + 𝑏 ) ∈ 𝐸 ) ) ) |
56 |
55
|
impancom |
⊢ ( ( 𝑏 ∈ ℤ ∧ ∃ 𝑥 ∈ ℤ 𝑏 = ( 2 · 𝑥 ) ) → ( 𝑎 ∈ ℤ → ( ∃ 𝑦 ∈ ℤ 𝑎 = ( 2 · 𝑦 ) → ( 𝑎 + 𝑏 ) ∈ 𝐸 ) ) ) |
57 |
56
|
com13 |
⊢ ( ∃ 𝑦 ∈ ℤ 𝑎 = ( 2 · 𝑦 ) → ( 𝑎 ∈ ℤ → ( ( 𝑏 ∈ ℤ ∧ ∃ 𝑥 ∈ ℤ 𝑏 = ( 2 · 𝑥 ) ) → ( 𝑎 + 𝑏 ) ∈ 𝐸 ) ) ) |
58 |
11 57
|
sylbi |
⊢ ( ∃ 𝑥 ∈ ℤ 𝑎 = ( 2 · 𝑥 ) → ( 𝑎 ∈ ℤ → ( ( 𝑏 ∈ ℤ ∧ ∃ 𝑥 ∈ ℤ 𝑏 = ( 2 · 𝑥 ) ) → ( 𝑎 + 𝑏 ) ∈ 𝐸 ) ) ) |
59 |
58
|
impcom |
⊢ ( ( 𝑎 ∈ ℤ ∧ ∃ 𝑥 ∈ ℤ 𝑎 = ( 2 · 𝑥 ) ) → ( ( 𝑏 ∈ ℤ ∧ ∃ 𝑥 ∈ ℤ 𝑏 = ( 2 · 𝑥 ) ) → ( 𝑎 + 𝑏 ) ∈ 𝐸 ) ) |
60 |
59
|
imp |
⊢ ( ( ( 𝑎 ∈ ℤ ∧ ∃ 𝑥 ∈ ℤ 𝑎 = ( 2 · 𝑥 ) ) ∧ ( 𝑏 ∈ ℤ ∧ ∃ 𝑥 ∈ ℤ 𝑏 = ( 2 · 𝑥 ) ) ) → ( 𝑎 + 𝑏 ) ∈ 𝐸 ) |
61 |
5 8 60
|
syl2anb |
⊢ ( ( 𝑎 ∈ 𝐸 ∧ 𝑏 ∈ 𝐸 ) → ( 𝑎 + 𝑏 ) ∈ 𝐸 ) |
62 |
61
|
rgen2 |
⊢ ∀ 𝑎 ∈ 𝐸 ∀ 𝑏 ∈ 𝐸 ( 𝑎 + 𝑏 ) ∈ 𝐸 |
63 |
|
0z |
⊢ 0 ∈ ℤ |
64 |
|
2cn |
⊢ 2 ∈ ℂ |
65 |
|
0zd |
⊢ ( 2 ∈ ℂ → 0 ∈ ℤ ) |
66 |
|
oveq2 |
⊢ ( 𝑥 = 0 → ( 2 · 𝑥 ) = ( 2 · 0 ) ) |
67 |
66
|
eqeq2d |
⊢ ( 𝑥 = 0 → ( 0 = ( 2 · 𝑥 ) ↔ 0 = ( 2 · 0 ) ) ) |
68 |
67
|
adantl |
⊢ ( ( 2 ∈ ℂ ∧ 𝑥 = 0 ) → ( 0 = ( 2 · 𝑥 ) ↔ 0 = ( 2 · 0 ) ) ) |
69 |
|
mul01 |
⊢ ( 2 ∈ ℂ → ( 2 · 0 ) = 0 ) |
70 |
69
|
eqcomd |
⊢ ( 2 ∈ ℂ → 0 = ( 2 · 0 ) ) |
71 |
65 68 70
|
rspcedvd |
⊢ ( 2 ∈ ℂ → ∃ 𝑥 ∈ ℤ 0 = ( 2 · 𝑥 ) ) |
72 |
64 71
|
ax-mp |
⊢ ∃ 𝑥 ∈ ℤ 0 = ( 2 · 𝑥 ) |
73 |
|
eqeq1 |
⊢ ( 𝑧 = 0 → ( 𝑧 = ( 2 · 𝑥 ) ↔ 0 = ( 2 · 𝑥 ) ) ) |
74 |
73
|
rexbidv |
⊢ ( 𝑧 = 0 → ( ∃ 𝑥 ∈ ℤ 𝑧 = ( 2 · 𝑥 ) ↔ ∃ 𝑥 ∈ ℤ 0 = ( 2 · 𝑥 ) ) ) |
75 |
74
|
elrab |
⊢ ( 0 ∈ { 𝑧 ∈ ℤ ∣ ∃ 𝑥 ∈ ℤ 𝑧 = ( 2 · 𝑥 ) } ↔ ( 0 ∈ ℤ ∧ ∃ 𝑥 ∈ ℤ 0 = ( 2 · 𝑥 ) ) ) |
76 |
63 72 75
|
mpbir2an |
⊢ 0 ∈ { 𝑧 ∈ ℤ ∣ ∃ 𝑥 ∈ ℤ 𝑧 = ( 2 · 𝑥 ) } |
77 |
76 1
|
eleqtrri |
⊢ 0 ∈ 𝐸 |
78 |
1 2
|
2zrngbas |
⊢ 𝐸 = ( Base ‘ 𝑅 ) |
79 |
1 2
|
2zrngadd |
⊢ + = ( +g ‘ 𝑅 ) |
80 |
78 79
|
ismgmn0 |
⊢ ( 0 ∈ 𝐸 → ( 𝑅 ∈ Mgm ↔ ∀ 𝑎 ∈ 𝐸 ∀ 𝑏 ∈ 𝐸 ( 𝑎 + 𝑏 ) ∈ 𝐸 ) ) |
81 |
77 80
|
ax-mp |
⊢ ( 𝑅 ∈ Mgm ↔ ∀ 𝑎 ∈ 𝐸 ∀ 𝑏 ∈ 𝐸 ( 𝑎 + 𝑏 ) ∈ 𝐸 ) |
82 |
62 81
|
mpbir |
⊢ 𝑅 ∈ Mgm |