Step | Hyp | Ref
| Expression |
1 | | grpoidval.2 |
. 2
⊢ 𝑈 = (GId‘𝐺) |
2 | | grpoidval.1 |
. . . 4
⊢ 𝑋 = ran 𝐺 |
3 | 2 | gidval 28775 |
. . 3
⊢ (𝐺 ∈ GrpOp →
(GId‘𝐺) =
(℩𝑢 ∈
𝑋 ∀𝑥 ∈ 𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥))) |
4 | | simpl 482 |
. . . . . . . . 9
⊢ (((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥) → (𝑢𝐺𝑥) = 𝑥) |
5 | 4 | ralimi 3086 |
. . . . . . . 8
⊢
(∀𝑥 ∈
𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥) → ∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥) |
6 | 5 | rgenw 3075 |
. . . . . . 7
⊢
∀𝑢 ∈
𝑋 (∀𝑥 ∈ 𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥) → ∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥) |
7 | 6 | a1i 11 |
. . . . . 6
⊢ (𝐺 ∈ GrpOp →
∀𝑢 ∈ 𝑋 (∀𝑥 ∈ 𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥) → ∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥)) |
8 | 2 | grpoidinv 28771 |
. . . . . . 7
⊢ (𝐺 ∈ GrpOp →
∃𝑢 ∈ 𝑋 ∀𝑥 ∈ 𝑋 (((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥) ∧ ∃𝑦 ∈ 𝑋 ((𝑦𝐺𝑥) = 𝑢 ∧ (𝑥𝐺𝑦) = 𝑢))) |
9 | | simpl 482 |
. . . . . . . . 9
⊢ ((((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥) ∧ ∃𝑦 ∈ 𝑋 ((𝑦𝐺𝑥) = 𝑢 ∧ (𝑥𝐺𝑦) = 𝑢)) → ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥)) |
10 | 9 | ralimi 3086 |
. . . . . . . 8
⊢
(∀𝑥 ∈
𝑋 (((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥) ∧ ∃𝑦 ∈ 𝑋 ((𝑦𝐺𝑥) = 𝑢 ∧ (𝑥𝐺𝑦) = 𝑢)) → ∀𝑥 ∈ 𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥)) |
11 | 10 | reximi 3174 |
. . . . . . 7
⊢
(∃𝑢 ∈
𝑋 ∀𝑥 ∈ 𝑋 (((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥) ∧ ∃𝑦 ∈ 𝑋 ((𝑦𝐺𝑥) = 𝑢 ∧ (𝑥𝐺𝑦) = 𝑢)) → ∃𝑢 ∈ 𝑋 ∀𝑥 ∈ 𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥)) |
12 | 8, 11 | syl 17 |
. . . . . 6
⊢ (𝐺 ∈ GrpOp →
∃𝑢 ∈ 𝑋 ∀𝑥 ∈ 𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥)) |
13 | 2 | grpoideu 28772 |
. . . . . 6
⊢ (𝐺 ∈ GrpOp →
∃!𝑢 ∈ 𝑋 ∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥) |
14 | 7, 12, 13 | 3jca 1126 |
. . . . 5
⊢ (𝐺 ∈ GrpOp →
(∀𝑢 ∈ 𝑋 (∀𝑥 ∈ 𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥) → ∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥) ∧ ∃𝑢 ∈ 𝑋 ∀𝑥 ∈ 𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥) ∧ ∃!𝑢 ∈ 𝑋 ∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥)) |
15 | | reupick2 4251 |
. . . . 5
⊢
(((∀𝑢 ∈
𝑋 (∀𝑥 ∈ 𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥) → ∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥) ∧ ∃𝑢 ∈ 𝑋 ∀𝑥 ∈ 𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥) ∧ ∃!𝑢 ∈ 𝑋 ∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥) ∧ 𝑢 ∈ 𝑋) → (∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥 ↔ ∀𝑥 ∈ 𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥))) |
16 | 14, 15 | sylan 579 |
. . . 4
⊢ ((𝐺 ∈ GrpOp ∧ 𝑢 ∈ 𝑋) → (∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥 ↔ ∀𝑥 ∈ 𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥))) |
17 | 16 | riotabidva 7232 |
. . 3
⊢ (𝐺 ∈ GrpOp →
(℩𝑢 ∈
𝑋 ∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥) = (℩𝑢 ∈ 𝑋 ∀𝑥 ∈ 𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥))) |
18 | 3, 17 | eqtr4d 2781 |
. 2
⊢ (𝐺 ∈ GrpOp →
(GId‘𝐺) =
(℩𝑢 ∈
𝑋 ∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥)) |
19 | 1, 18 | syl5eq 2791 |
1
⊢ (𝐺 ∈ GrpOp → 𝑈 = (℩𝑢 ∈ 𝑋 ∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥)) |