Step | Hyp | Ref
| Expression |
1 | | brgic 18800 |
. 2
⊢ (𝐺 ≃𝑔
𝐻 ↔ (𝐺 GrpIso 𝐻) ≠ ∅) |
2 | | n0 4277 |
. . 3
⊢ ((𝐺 GrpIso 𝐻) ≠ ∅ ↔ ∃𝑥 𝑥 ∈ (𝐺 GrpIso 𝐻)) |
3 | | gimghm 18795 |
. . . . . . . 8
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → 𝑥 ∈ (𝐺 GrpHom 𝐻)) |
4 | | ghmgrp1 18751 |
. . . . . . . 8
⊢ (𝑥 ∈ (𝐺 GrpHom 𝐻) → 𝐺 ∈ Grp) |
5 | 3, 4 | syl 17 |
. . . . . . 7
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → 𝐺 ∈ Grp) |
6 | | ghmgrp2 18752 |
. . . . . . . 8
⊢ (𝑥 ∈ (𝐺 GrpHom 𝐻) → 𝐻 ∈ Grp) |
7 | 3, 6 | syl 17 |
. . . . . . 7
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → 𝐻 ∈ Grp) |
8 | 5, 7 | 2thd 264 |
. . . . . 6
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → (𝐺 ∈ Grp ↔ 𝐻 ∈ Grp)) |
9 | 5 | grpmndd 18504 |
. . . . . . . . 9
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → 𝐺 ∈ Mnd) |
10 | 7 | grpmndd 18504 |
. . . . . . . . 9
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → 𝐻 ∈ Mnd) |
11 | 9, 10 | 2thd 264 |
. . . . . . . 8
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → (𝐺 ∈ Mnd ↔ 𝐻 ∈ Mnd)) |
12 | | eqid 2738 |
. . . . . . . . . . . . . . . 16
⊢
(Base‘𝐺) =
(Base‘𝐺) |
13 | | eqid 2738 |
. . . . . . . . . . . . . . . 16
⊢
(Base‘𝐻) =
(Base‘𝐻) |
14 | 12, 13 | gimf1o 18794 |
. . . . . . . . . . . . . . 15
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → 𝑥:(Base‘𝐺)–1-1-onto→(Base‘𝐻)) |
15 | | f1of1 6699 |
. . . . . . . . . . . . . . 15
⊢ (𝑥:(Base‘𝐺)–1-1-onto→(Base‘𝐻) → 𝑥:(Base‘𝐺)–1-1→(Base‘𝐻)) |
16 | 14, 15 | syl 17 |
. . . . . . . . . . . . . 14
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → 𝑥:(Base‘𝐺)–1-1→(Base‘𝐻)) |
17 | 16 | adantr 480 |
. . . . . . . . . . . . 13
⊢ ((𝑥 ∈ (𝐺 GrpIso 𝐻) ∧ (𝑦 ∈ (Base‘𝐺) ∧ 𝑧 ∈ (Base‘𝐺))) → 𝑥:(Base‘𝐺)–1-1→(Base‘𝐻)) |
18 | 5 | adantr 480 |
. . . . . . . . . . . . . 14
⊢ ((𝑥 ∈ (𝐺 GrpIso 𝐻) ∧ (𝑦 ∈ (Base‘𝐺) ∧ 𝑧 ∈ (Base‘𝐺))) → 𝐺 ∈ Grp) |
19 | | simprl 767 |
. . . . . . . . . . . . . 14
⊢ ((𝑥 ∈ (𝐺 GrpIso 𝐻) ∧ (𝑦 ∈ (Base‘𝐺) ∧ 𝑧 ∈ (Base‘𝐺))) → 𝑦 ∈ (Base‘𝐺)) |
20 | | simprr 769 |
. . . . . . . . . . . . . 14
⊢ ((𝑥 ∈ (𝐺 GrpIso 𝐻) ∧ (𝑦 ∈ (Base‘𝐺) ∧ 𝑧 ∈ (Base‘𝐺))) → 𝑧 ∈ (Base‘𝐺)) |
21 | | eqid 2738 |
. . . . . . . . . . . . . . 15
⊢
(+g‘𝐺) = (+g‘𝐺) |
22 | 12, 21 | grpcl 18500 |
. . . . . . . . . . . . . 14
⊢ ((𝐺 ∈ Grp ∧ 𝑦 ∈ (Base‘𝐺) ∧ 𝑧 ∈ (Base‘𝐺)) → (𝑦(+g‘𝐺)𝑧) ∈ (Base‘𝐺)) |
23 | 18, 19, 20, 22 | syl3anc 1369 |
. . . . . . . . . . . . 13
⊢ ((𝑥 ∈ (𝐺 GrpIso 𝐻) ∧ (𝑦 ∈ (Base‘𝐺) ∧ 𝑧 ∈ (Base‘𝐺))) → (𝑦(+g‘𝐺)𝑧) ∈ (Base‘𝐺)) |
24 | 12, 21 | grpcl 18500 |
. . . . . . . . . . . . . 14
⊢ ((𝐺 ∈ Grp ∧ 𝑧 ∈ (Base‘𝐺) ∧ 𝑦 ∈ (Base‘𝐺)) → (𝑧(+g‘𝐺)𝑦) ∈ (Base‘𝐺)) |
25 | 18, 20, 19, 24 | syl3anc 1369 |
. . . . . . . . . . . . 13
⊢ ((𝑥 ∈ (𝐺 GrpIso 𝐻) ∧ (𝑦 ∈ (Base‘𝐺) ∧ 𝑧 ∈ (Base‘𝐺))) → (𝑧(+g‘𝐺)𝑦) ∈ (Base‘𝐺)) |
26 | | f1fveq 7116 |
. . . . . . . . . . . . 13
⊢ ((𝑥:(Base‘𝐺)–1-1→(Base‘𝐻) ∧ ((𝑦(+g‘𝐺)𝑧) ∈ (Base‘𝐺) ∧ (𝑧(+g‘𝐺)𝑦) ∈ (Base‘𝐺))) → ((𝑥‘(𝑦(+g‘𝐺)𝑧)) = (𝑥‘(𝑧(+g‘𝐺)𝑦)) ↔ (𝑦(+g‘𝐺)𝑧) = (𝑧(+g‘𝐺)𝑦))) |
27 | 17, 23, 25, 26 | syl12anc 833 |
. . . . . . . . . . . 12
⊢ ((𝑥 ∈ (𝐺 GrpIso 𝐻) ∧ (𝑦 ∈ (Base‘𝐺) ∧ 𝑧 ∈ (Base‘𝐺))) → ((𝑥‘(𝑦(+g‘𝐺)𝑧)) = (𝑥‘(𝑧(+g‘𝐺)𝑦)) ↔ (𝑦(+g‘𝐺)𝑧) = (𝑧(+g‘𝐺)𝑦))) |
28 | 3 | adantr 480 |
. . . . . . . . . . . . . 14
⊢ ((𝑥 ∈ (𝐺 GrpIso 𝐻) ∧ (𝑦 ∈ (Base‘𝐺) ∧ 𝑧 ∈ (Base‘𝐺))) → 𝑥 ∈ (𝐺 GrpHom 𝐻)) |
29 | | eqid 2738 |
. . . . . . . . . . . . . . 15
⊢
(+g‘𝐻) = (+g‘𝐻) |
30 | 12, 21, 29 | ghmlin 18754 |
. . . . . . . . . . . . . 14
⊢ ((𝑥 ∈ (𝐺 GrpHom 𝐻) ∧ 𝑦 ∈ (Base‘𝐺) ∧ 𝑧 ∈ (Base‘𝐺)) → (𝑥‘(𝑦(+g‘𝐺)𝑧)) = ((𝑥‘𝑦)(+g‘𝐻)(𝑥‘𝑧))) |
31 | 28, 19, 20, 30 | syl3anc 1369 |
. . . . . . . . . . . . 13
⊢ ((𝑥 ∈ (𝐺 GrpIso 𝐻) ∧ (𝑦 ∈ (Base‘𝐺) ∧ 𝑧 ∈ (Base‘𝐺))) → (𝑥‘(𝑦(+g‘𝐺)𝑧)) = ((𝑥‘𝑦)(+g‘𝐻)(𝑥‘𝑧))) |
32 | 12, 21, 29 | ghmlin 18754 |
. . . . . . . . . . . . . 14
⊢ ((𝑥 ∈ (𝐺 GrpHom 𝐻) ∧ 𝑧 ∈ (Base‘𝐺) ∧ 𝑦 ∈ (Base‘𝐺)) → (𝑥‘(𝑧(+g‘𝐺)𝑦)) = ((𝑥‘𝑧)(+g‘𝐻)(𝑥‘𝑦))) |
33 | 28, 20, 19, 32 | syl3anc 1369 |
. . . . . . . . . . . . 13
⊢ ((𝑥 ∈ (𝐺 GrpIso 𝐻) ∧ (𝑦 ∈ (Base‘𝐺) ∧ 𝑧 ∈ (Base‘𝐺))) → (𝑥‘(𝑧(+g‘𝐺)𝑦)) = ((𝑥‘𝑧)(+g‘𝐻)(𝑥‘𝑦))) |
34 | 31, 33 | eqeq12d 2754 |
. . . . . . . . . . . 12
⊢ ((𝑥 ∈ (𝐺 GrpIso 𝐻) ∧ (𝑦 ∈ (Base‘𝐺) ∧ 𝑧 ∈ (Base‘𝐺))) → ((𝑥‘(𝑦(+g‘𝐺)𝑧)) = (𝑥‘(𝑧(+g‘𝐺)𝑦)) ↔ ((𝑥‘𝑦)(+g‘𝐻)(𝑥‘𝑧)) = ((𝑥‘𝑧)(+g‘𝐻)(𝑥‘𝑦)))) |
35 | 27, 34 | bitr3d 280 |
. . . . . . . . . . 11
⊢ ((𝑥 ∈ (𝐺 GrpIso 𝐻) ∧ (𝑦 ∈ (Base‘𝐺) ∧ 𝑧 ∈ (Base‘𝐺))) → ((𝑦(+g‘𝐺)𝑧) = (𝑧(+g‘𝐺)𝑦) ↔ ((𝑥‘𝑦)(+g‘𝐻)(𝑥‘𝑧)) = ((𝑥‘𝑧)(+g‘𝐻)(𝑥‘𝑦)))) |
36 | 35 | 2ralbidva 3121 |
. . . . . . . . . 10
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → (∀𝑦 ∈ (Base‘𝐺)∀𝑧 ∈ (Base‘𝐺)(𝑦(+g‘𝐺)𝑧) = (𝑧(+g‘𝐺)𝑦) ↔ ∀𝑦 ∈ (Base‘𝐺)∀𝑧 ∈ (Base‘𝐺)((𝑥‘𝑦)(+g‘𝐻)(𝑥‘𝑧)) = ((𝑥‘𝑧)(+g‘𝐻)(𝑥‘𝑦)))) |
37 | | f1ofo 6707 |
. . . . . . . . . . . . . . 15
⊢ (𝑥:(Base‘𝐺)–1-1-onto→(Base‘𝐻) → 𝑥:(Base‘𝐺)–onto→(Base‘𝐻)) |
38 | | foima 6677 |
. . . . . . . . . . . . . . 15
⊢ (𝑥:(Base‘𝐺)–onto→(Base‘𝐻) → (𝑥 “ (Base‘𝐺)) = (Base‘𝐻)) |
39 | 37, 38 | syl 17 |
. . . . . . . . . . . . . 14
⊢ (𝑥:(Base‘𝐺)–1-1-onto→(Base‘𝐻) → (𝑥 “ (Base‘𝐺)) = (Base‘𝐻)) |
40 | 14, 39 | syl 17 |
. . . . . . . . . . . . 13
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → (𝑥 “ (Base‘𝐺)) = (Base‘𝐻)) |
41 | 40 | raleqdv 3339 |
. . . . . . . . . . . 12
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → (∀𝑣 ∈ (𝑥 “ (Base‘𝐺))((𝑥‘𝑦)(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)(𝑥‘𝑦)) ↔ ∀𝑣 ∈ (Base‘𝐻)((𝑥‘𝑦)(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)(𝑥‘𝑦)))) |
42 | | f1ofn 6701 |
. . . . . . . . . . . . . 14
⊢ (𝑥:(Base‘𝐺)–1-1-onto→(Base‘𝐻) → 𝑥 Fn (Base‘𝐺)) |
43 | 14, 42 | syl 17 |
. . . . . . . . . . . . 13
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → 𝑥 Fn (Base‘𝐺)) |
44 | | ssid 3939 |
. . . . . . . . . . . . 13
⊢
(Base‘𝐺)
⊆ (Base‘𝐺) |
45 | | oveq2 7263 |
. . . . . . . . . . . . . . 15
⊢ (𝑣 = (𝑥‘𝑧) → ((𝑥‘𝑦)(+g‘𝐻)𝑣) = ((𝑥‘𝑦)(+g‘𝐻)(𝑥‘𝑧))) |
46 | | oveq1 7262 |
. . . . . . . . . . . . . . 15
⊢ (𝑣 = (𝑥‘𝑧) → (𝑣(+g‘𝐻)(𝑥‘𝑦)) = ((𝑥‘𝑧)(+g‘𝐻)(𝑥‘𝑦))) |
47 | 45, 46 | eqeq12d 2754 |
. . . . . . . . . . . . . 14
⊢ (𝑣 = (𝑥‘𝑧) → (((𝑥‘𝑦)(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)(𝑥‘𝑦)) ↔ ((𝑥‘𝑦)(+g‘𝐻)(𝑥‘𝑧)) = ((𝑥‘𝑧)(+g‘𝐻)(𝑥‘𝑦)))) |
48 | 47 | ralima 7096 |
. . . . . . . . . . . . 13
⊢ ((𝑥 Fn (Base‘𝐺) ∧ (Base‘𝐺) ⊆ (Base‘𝐺)) → (∀𝑣 ∈ (𝑥 “ (Base‘𝐺))((𝑥‘𝑦)(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)(𝑥‘𝑦)) ↔ ∀𝑧 ∈ (Base‘𝐺)((𝑥‘𝑦)(+g‘𝐻)(𝑥‘𝑧)) = ((𝑥‘𝑧)(+g‘𝐻)(𝑥‘𝑦)))) |
49 | 43, 44, 48 | sylancl 585 |
. . . . . . . . . . . 12
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → (∀𝑣 ∈ (𝑥 “ (Base‘𝐺))((𝑥‘𝑦)(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)(𝑥‘𝑦)) ↔ ∀𝑧 ∈ (Base‘𝐺)((𝑥‘𝑦)(+g‘𝐻)(𝑥‘𝑧)) = ((𝑥‘𝑧)(+g‘𝐻)(𝑥‘𝑦)))) |
50 | 41, 49 | bitr3d 280 |
. . . . . . . . . . 11
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → (∀𝑣 ∈ (Base‘𝐻)((𝑥‘𝑦)(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)(𝑥‘𝑦)) ↔ ∀𝑧 ∈ (Base‘𝐺)((𝑥‘𝑦)(+g‘𝐻)(𝑥‘𝑧)) = ((𝑥‘𝑧)(+g‘𝐻)(𝑥‘𝑦)))) |
51 | 50 | ralbidv 3120 |
. . . . . . . . . 10
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → (∀𝑦 ∈ (Base‘𝐺)∀𝑣 ∈ (Base‘𝐻)((𝑥‘𝑦)(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)(𝑥‘𝑦)) ↔ ∀𝑦 ∈ (Base‘𝐺)∀𝑧 ∈ (Base‘𝐺)((𝑥‘𝑦)(+g‘𝐻)(𝑥‘𝑧)) = ((𝑥‘𝑧)(+g‘𝐻)(𝑥‘𝑦)))) |
52 | 36, 51 | bitr4d 281 |
. . . . . . . . 9
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → (∀𝑦 ∈ (Base‘𝐺)∀𝑧 ∈ (Base‘𝐺)(𝑦(+g‘𝐺)𝑧) = (𝑧(+g‘𝐺)𝑦) ↔ ∀𝑦 ∈ (Base‘𝐺)∀𝑣 ∈ (Base‘𝐻)((𝑥‘𝑦)(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)(𝑥‘𝑦)))) |
53 | 40 | raleqdv 3339 |
. . . . . . . . . 10
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → (∀𝑤 ∈ (𝑥 “ (Base‘𝐺))∀𝑣 ∈ (Base‘𝐻)(𝑤(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)𝑤) ↔ ∀𝑤 ∈ (Base‘𝐻)∀𝑣 ∈ (Base‘𝐻)(𝑤(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)𝑤))) |
54 | | oveq1 7262 |
. . . . . . . . . . . . . 14
⊢ (𝑤 = (𝑥‘𝑦) → (𝑤(+g‘𝐻)𝑣) = ((𝑥‘𝑦)(+g‘𝐻)𝑣)) |
55 | | oveq2 7263 |
. . . . . . . . . . . . . 14
⊢ (𝑤 = (𝑥‘𝑦) → (𝑣(+g‘𝐻)𝑤) = (𝑣(+g‘𝐻)(𝑥‘𝑦))) |
56 | 54, 55 | eqeq12d 2754 |
. . . . . . . . . . . . 13
⊢ (𝑤 = (𝑥‘𝑦) → ((𝑤(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)𝑤) ↔ ((𝑥‘𝑦)(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)(𝑥‘𝑦)))) |
57 | 56 | ralbidv 3120 |
. . . . . . . . . . . 12
⊢ (𝑤 = (𝑥‘𝑦) → (∀𝑣 ∈ (Base‘𝐻)(𝑤(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)𝑤) ↔ ∀𝑣 ∈ (Base‘𝐻)((𝑥‘𝑦)(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)(𝑥‘𝑦)))) |
58 | 57 | ralima 7096 |
. . . . . . . . . . 11
⊢ ((𝑥 Fn (Base‘𝐺) ∧ (Base‘𝐺) ⊆ (Base‘𝐺)) → (∀𝑤 ∈ (𝑥 “ (Base‘𝐺))∀𝑣 ∈ (Base‘𝐻)(𝑤(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)𝑤) ↔ ∀𝑦 ∈ (Base‘𝐺)∀𝑣 ∈ (Base‘𝐻)((𝑥‘𝑦)(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)(𝑥‘𝑦)))) |
59 | 43, 44, 58 | sylancl 585 |
. . . . . . . . . 10
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → (∀𝑤 ∈ (𝑥 “ (Base‘𝐺))∀𝑣 ∈ (Base‘𝐻)(𝑤(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)𝑤) ↔ ∀𝑦 ∈ (Base‘𝐺)∀𝑣 ∈ (Base‘𝐻)((𝑥‘𝑦)(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)(𝑥‘𝑦)))) |
60 | 53, 59 | bitr3d 280 |
. . . . . . . . 9
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → (∀𝑤 ∈ (Base‘𝐻)∀𝑣 ∈ (Base‘𝐻)(𝑤(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)𝑤) ↔ ∀𝑦 ∈ (Base‘𝐺)∀𝑣 ∈ (Base‘𝐻)((𝑥‘𝑦)(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)(𝑥‘𝑦)))) |
61 | 52, 60 | bitr4d 281 |
. . . . . . . 8
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → (∀𝑦 ∈ (Base‘𝐺)∀𝑧 ∈ (Base‘𝐺)(𝑦(+g‘𝐺)𝑧) = (𝑧(+g‘𝐺)𝑦) ↔ ∀𝑤 ∈ (Base‘𝐻)∀𝑣 ∈ (Base‘𝐻)(𝑤(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)𝑤))) |
62 | 11, 61 | anbi12d 630 |
. . . . . . 7
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → ((𝐺 ∈ Mnd ∧ ∀𝑦 ∈ (Base‘𝐺)∀𝑧 ∈ (Base‘𝐺)(𝑦(+g‘𝐺)𝑧) = (𝑧(+g‘𝐺)𝑦)) ↔ (𝐻 ∈ Mnd ∧ ∀𝑤 ∈ (Base‘𝐻)∀𝑣 ∈ (Base‘𝐻)(𝑤(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)𝑤)))) |
63 | 12, 21 | iscmn 19309 |
. . . . . . 7
⊢ (𝐺 ∈ CMnd ↔ (𝐺 ∈ Mnd ∧ ∀𝑦 ∈ (Base‘𝐺)∀𝑧 ∈ (Base‘𝐺)(𝑦(+g‘𝐺)𝑧) = (𝑧(+g‘𝐺)𝑦))) |
64 | 13, 29 | iscmn 19309 |
. . . . . . 7
⊢ (𝐻 ∈ CMnd ↔ (𝐻 ∈ Mnd ∧ ∀𝑤 ∈ (Base‘𝐻)∀𝑣 ∈ (Base‘𝐻)(𝑤(+g‘𝐻)𝑣) = (𝑣(+g‘𝐻)𝑤))) |
65 | 62, 63, 64 | 3bitr4g 313 |
. . . . . 6
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → (𝐺 ∈ CMnd ↔ 𝐻 ∈ CMnd)) |
66 | 8, 65 | anbi12d 630 |
. . . . 5
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → ((𝐺 ∈ Grp ∧ 𝐺 ∈ CMnd) ↔ (𝐻 ∈ Grp ∧ 𝐻 ∈ CMnd))) |
67 | | isabl 19305 |
. . . . 5
⊢ (𝐺 ∈ Abel ↔ (𝐺 ∈ Grp ∧ 𝐺 ∈ CMnd)) |
68 | | isabl 19305 |
. . . . 5
⊢ (𝐻 ∈ Abel ↔ (𝐻 ∈ Grp ∧ 𝐻 ∈ CMnd)) |
69 | 66, 67, 68 | 3bitr4g 313 |
. . . 4
⊢ (𝑥 ∈ (𝐺 GrpIso 𝐻) → (𝐺 ∈ Abel ↔ 𝐻 ∈ Abel)) |
70 | 69 | exlimiv 1934 |
. . 3
⊢
(∃𝑥 𝑥 ∈ (𝐺 GrpIso 𝐻) → (𝐺 ∈ Abel ↔ 𝐻 ∈ Abel)) |
71 | 2, 70 | sylbi 216 |
. 2
⊢ ((𝐺 GrpIso 𝐻) ≠ ∅ → (𝐺 ∈ Abel ↔ 𝐻 ∈ Abel)) |
72 | 1, 71 | sylbi 216 |
1
⊢ (𝐺 ≃𝑔
𝐻 → (𝐺 ∈ Abel ↔ 𝐻 ∈ Abel)) |