| Step | Hyp | Ref
| Expression |
| 1 | | grpoidval.2 |
. 2
⊢ 𝑈 = (GId‘𝐺) |
| 2 | | grpoidval.1 |
. . . 4
⊢ 𝑋 = ran 𝐺 |
| 3 | 2 | gidval 30493 |
. . 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 3073 |
. . . . . . . 8
⊢
(∀𝑥 ∈
𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥) → ∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥) |
| 6 | 5 | rgenw 3055 |
. . . . . . 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 30489 |
. . . . . . 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 3073 |
. . . . . . . 8
⊢
(∀𝑥 ∈
𝑋 (((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥) ∧ ∃𝑦 ∈ 𝑋 ((𝑦𝐺𝑥) = 𝑢 ∧ (𝑥𝐺𝑦) = 𝑢)) → ∀𝑥 ∈ 𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥)) |
| 11 | 10 | reximi 3074 |
. . . . . . 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 30490 |
. . . . . 6
⊢ (𝐺 ∈ GrpOp →
∃!𝑢 ∈ 𝑋 ∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥) |
| 14 | 7, 12, 13 | 3jca 1128 |
. . . . 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 4306 |
. . . . 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 580 |
. . . 4
⊢ ((𝐺 ∈ GrpOp ∧ 𝑢 ∈ 𝑋) → (∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥 ↔ ∀𝑥 ∈ 𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥))) |
| 17 | 16 | riotabidva 7381 |
. . 3
⊢ (𝐺 ∈ GrpOp →
(℩𝑢 ∈
𝑋 ∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥) = (℩𝑢 ∈ 𝑋 ∀𝑥 ∈ 𝑋 ((𝑢𝐺𝑥) = 𝑥 ∧ (𝑥𝐺𝑢) = 𝑥))) |
| 18 | 3, 17 | eqtr4d 2773 |
. 2
⊢ (𝐺 ∈ GrpOp →
(GId‘𝐺) =
(℩𝑢 ∈
𝑋 ∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥)) |
| 19 | 1, 18 | eqtrid 2782 |
1
⊢ (𝐺 ∈ GrpOp → 𝑈 = (℩𝑢 ∈ 𝑋 ∀𝑥 ∈ 𝑋 (𝑢𝐺𝑥) = 𝑥)) |