| Step | Hyp | Ref
| Expression |
| 1 | | isdrng3.b |
. . . . 5
⊢ 𝐵 = (Base‘𝑅) |
| 2 | 1 | isdrng3lem0 20850 |
. . . 4
⊢
(Base‘((mulGrp‘𝑅) ↾s (𝐵 ∖ { 0 }))) = (𝐵 ∖ { 0 }) |
| 3 | 2 | eqcomi 2772 |
. . 3
⊢ (𝐵 ∖ { 0 }) =
(Base‘((mulGrp‘𝑅) ↾s (𝐵 ∖ { 0 }))) |
| 4 | 3 | a1i 11 |
. 2
⊢ ((𝑅 ∈ Ring ∧ 1 ≠ 0 ∧
∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ) → (𝐵 ∖ { 0 }) =
(Base‘((mulGrp‘𝑅) ↾s (𝐵 ∖ { 0 })))) |
| 5 | 1 | fvexi 6895 |
. . . . 5
⊢ 𝐵 ∈ V |
| 6 | 5 | a1i 11 |
. . . 4
⊢ ((𝑅 ∈ Ring ∧ 1 ≠ 0 ∧
∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ) → 𝐵 ∈ V) |
| 7 | 6 | difexd 5302 |
. . 3
⊢ ((𝑅 ∈ Ring ∧ 1 ≠ 0 ∧
∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ) → (𝐵 ∖ { 0 }) ∈
V) |
| 8 | | eqid 2763 |
. . . 4
⊢
((mulGrp‘𝑅)
↾s (𝐵
∖ { 0 })) = ((mulGrp‘𝑅) ↾s (𝐵 ∖ { 0 })) |
| 9 | | eqid 2763 |
. . . . 5
⊢
(mulGrp‘𝑅) =
(mulGrp‘𝑅) |
| 10 | | isdrng3.t |
. . . . 5
⊢ · =
(.r‘𝑅) |
| 11 | 9, 10 | mgpplusg 20215 |
. . . 4
⊢ · =
(+g‘(mulGrp‘𝑅)) |
| 12 | 8, 11 | ressplusg 17339 |
. . 3
⊢ ((𝐵 ∖ { 0 }) ∈ V → · =
(+g‘((mulGrp‘𝑅) ↾s (𝐵 ∖ { 0 })))) |
| 13 | 7, 12 | syl 18 |
. 2
⊢ ((𝑅 ∈ Ring ∧ 1 ≠ 0 ∧
∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ) → · =
(+g‘((mulGrp‘𝑅) ↾s (𝐵 ∖ { 0 })))) |
| 14 | | simp1 1154 |
. . . 4
⊢ ((𝑅 ∈ Ring ∧ 1 ≠ 0 ∧
∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ) → 𝑅 ∈ Ring) |
| 15 | | eldifi 4085 |
. . . 4
⊢ (𝑎 ∈ (𝐵 ∖ { 0 }) → 𝑎 ∈ 𝐵) |
| 16 | | eldifi 4085 |
. . . 4
⊢ (𝑏 ∈ (𝐵 ∖ { 0 }) → 𝑏 ∈ 𝐵) |
| 17 | 1, 10 | ringcl 20327 |
. . . 4
⊢ ((𝑅 ∈ Ring ∧ 𝑎 ∈ 𝐵 ∧ 𝑏 ∈ 𝐵) → (𝑎 · 𝑏) ∈ 𝐵) |
| 18 | 14, 15, 16, 17 | syl3an 1178 |
. . 3
⊢ (((𝑅 ∈ Ring ∧ 1 ≠ 0 ∧
∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ) ∧ 𝑎 ∈ (𝐵 ∖ { 0 }) ∧ 𝑏 ∈ (𝐵 ∖ { 0 })) → (𝑎 · 𝑏) ∈ 𝐵) |
| 19 | | oveq2 7418 |
. . . . . . . . . . . 12
⊢ (𝑥 = 𝑎 → (𝑦 · 𝑥) = (𝑦 · 𝑎)) |
| 20 | 19 | eqeq1d 2765 |
. . . . . . . . . . 11
⊢ (𝑥 = 𝑎 → ((𝑦 · 𝑥) = 1 ↔ (𝑦 · 𝑎) = 1 )) |
| 21 | 20 | rexbidv 3189 |
. . . . . . . . . 10
⊢ (𝑥 = 𝑎 → (∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ↔ ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 )) |
| 22 | 21 | rspcv 3577 |
. . . . . . . . 9
⊢ (𝑎 ∈ (𝐵 ∖ { 0 }) → (∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 → ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 )) |
| 23 | 22 | imdistanri 579 |
. . . . . . . 8
⊢
((∀𝑥 ∈
(𝐵 ∖ { 0
})∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ∧ 𝑎 ∈ (𝐵 ∖ { 0 })) → (∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 ∧ 𝑎 ∈ (𝐵 ∖ { 0 }))) |
| 24 | | eldifsn 4753 |
. . . . . . . . . . 11
⊢ (𝑏 ∈ (𝐵 ∖ { 0 }) ↔ (𝑏 ∈ 𝐵 ∧ 𝑏 ≠ 0 )) |
| 25 | | isdrng3.1 |
. . . . . . . . . . . . . . . . . . 19
⊢ 1 =
(1r‘𝑅) |
| 26 | | isdrng3.0 |
. . . . . . . . . . . . . . . . . . 19
⊢ 0 =
(0g‘𝑅) |
| 27 | | simp1 1154 |
. . . . . . . . . . . . . . . . . . . 20
⊢ ((𝑅 ∈ Ring ∧ 𝑎 ∈ 𝐵 ∧ ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 ) → 𝑅 ∈ Ring) |
| 28 | 27 | adantr 485 |
. . . . . . . . . . . . . . . . . . 19
⊢ (((𝑅 ∈ Ring ∧ 𝑎 ∈ 𝐵 ∧ ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 ) ∧ 𝑏 ∈ 𝐵) → 𝑅 ∈ Ring) |
| 29 | | simpl2 1211 |
. . . . . . . . . . . . . . . . . . 19
⊢ (((𝑅 ∈ Ring ∧ 𝑎 ∈ 𝐵 ∧ ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 ) ∧ 𝑏 ∈ 𝐵) → 𝑎 ∈ 𝐵) |
| 30 | | difss 4090 |
. . . . . . . . . . . . . . . . . . . . . . 23
⊢ (𝐵 ∖ { 0 }) ⊆ 𝐵 |
| 31 | | ssrexv 4007 |
. . . . . . . . . . . . . . . . . . . . . . 23
⊢ ((𝐵 ∖ { 0 }) ⊆ 𝐵 → (∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 → ∃𝑦 ∈ 𝐵 (𝑦 · 𝑎) = 1 )) |
| 32 | 30, 31 | ax-mp 5 |
. . . . . . . . . . . . . . . . . . . . . 22
⊢
(∃𝑦 ∈
(𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 → ∃𝑦 ∈ 𝐵 (𝑦 · 𝑎) = 1 ) |
| 33 | | oveq1 7417 |
. . . . . . . . . . . . . . . . . . . . . . . 24
⊢ (𝑦 = 𝑐 → (𝑦 · 𝑎) = (𝑐 · 𝑎)) |
| 34 | 33 | eqeq1d 2765 |
. . . . . . . . . . . . . . . . . . . . . . 23
⊢ (𝑦 = 𝑐 → ((𝑦 · 𝑎) = 1 ↔ (𝑐 · 𝑎) = 1 )) |
| 35 | 34 | cbvrexvw 3244 |
. . . . . . . . . . . . . . . . . . . . . 22
⊢
(∃𝑦 ∈
𝐵 (𝑦 · 𝑎) = 1 ↔ ∃𝑐 ∈ 𝐵 (𝑐 · 𝑎) = 1 ) |
| 36 | 32, 35 | sylib 221 |
. . . . . . . . . . . . . . . . . . . . 21
⊢
(∃𝑦 ∈
(𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 → ∃𝑐 ∈ 𝐵 (𝑐 · 𝑎) = 1 ) |
| 37 | 36 | 3ad2ant3 1153 |
. . . . . . . . . . . . . . . . . . . 20
⊢ ((𝑅 ∈ Ring ∧ 𝑎 ∈ 𝐵 ∧ ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 ) → ∃𝑐 ∈ 𝐵 (𝑐 · 𝑎) = 1 ) |
| 38 | 37 | adantr 485 |
. . . . . . . . . . . . . . . . . . 19
⊢ (((𝑅 ∈ Ring ∧ 𝑎 ∈ 𝐵 ∧ ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 ) ∧ 𝑏 ∈ 𝐵) → ∃𝑐 ∈ 𝐵 (𝑐 · 𝑎) = 1 ) |
| 39 | | simpr 489 |
. . . . . . . . . . . . . . . . . . 19
⊢ (((𝑅 ∈ Ring ∧ 𝑎 ∈ 𝐵 ∧ ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 ) ∧ 𝑏 ∈ 𝐵) → 𝑏 ∈ 𝐵) |
| 40 | 1, 10, 25, 26, 28, 29, 38, 39 | ringinvnzdiv 20380 |
. . . . . . . . . . . . . . . . . 18
⊢ (((𝑅 ∈ Ring ∧ 𝑎 ∈ 𝐵 ∧ ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 ) ∧ 𝑏 ∈ 𝐵) → ((𝑎 · 𝑏) = 0 ↔ 𝑏 = 0 )) |
| 41 | 40 | biimpd 232 |
. . . . . . . . . . . . . . . . 17
⊢ (((𝑅 ∈ Ring ∧ 𝑎 ∈ 𝐵 ∧ ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 ) ∧ 𝑏 ∈ 𝐵) → ((𝑎 · 𝑏) = 0 → 𝑏 = 0 )) |
| 42 | 41 | ex 417 |
. . . . . . . . . . . . . . . 16
⊢ ((𝑅 ∈ Ring ∧ 𝑎 ∈ 𝐵 ∧ ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 ) → (𝑏 ∈ 𝐵 → ((𝑎 · 𝑏) = 0 → 𝑏 = 0 ))) |
| 43 | 15, 42 | syl3an2 1182 |
. . . . . . . . . . . . . . 15
⊢ ((𝑅 ∈ Ring ∧ 𝑎 ∈ (𝐵 ∖ { 0 }) ∧ ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 ) → (𝑏 ∈ 𝐵 → ((𝑎 · 𝑏) = 0 → 𝑏 = 0 ))) |
| 44 | 43 | 3expb 1138 |
. . . . . . . . . . . . . 14
⊢ ((𝑅 ∈ Ring ∧ (𝑎 ∈ (𝐵 ∖ { 0 }) ∧ ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 )) → (𝑏 ∈ 𝐵 → ((𝑎 · 𝑏) = 0 → 𝑏 = 0 ))) |
| 45 | 44 | imp 411 |
. . . . . . . . . . . . 13
⊢ (((𝑅 ∈ Ring ∧ (𝑎 ∈ (𝐵 ∖ { 0 }) ∧ ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 )) ∧ 𝑏 ∈ 𝐵) → ((𝑎 · 𝑏) = 0 → 𝑏 = 0 )) |
| 46 | 45 | necon3d 2979 |
. . . . . . . . . . . 12
⊢ (((𝑅 ∈ Ring ∧ (𝑎 ∈ (𝐵 ∖ { 0 }) ∧ ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 )) ∧ 𝑏 ∈ 𝐵) → (𝑏 ≠ 0 → (𝑎 · 𝑏) ≠ 0 )) |
| 47 | 46 | impr 459 |
. . . . . . . . . . 11
⊢ (((𝑅 ∈ Ring ∧ (𝑎 ∈ (𝐵 ∖ { 0 }) ∧ ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 )) ∧ (𝑏 ∈ 𝐵 ∧ 𝑏 ≠ 0 )) → (𝑎 · 𝑏) ≠ 0 ) |
| 48 | 24, 47 | sylan2b 605 |
. . . . . . . . . 10
⊢ (((𝑅 ∈ Ring ∧ (𝑎 ∈ (𝐵 ∖ { 0 }) ∧ ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 )) ∧ 𝑏 ∈ (𝐵 ∖ { 0 })) → (𝑎 · 𝑏) ≠ 0 ) |
| 49 | 48 | an32s 664 |
. . . . . . . . 9
⊢ (((𝑅 ∈ Ring ∧ 𝑏 ∈ (𝐵 ∖ { 0 })) ∧ (𝑎 ∈ (𝐵 ∖ { 0 }) ∧ ∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 )) → (𝑎 · 𝑏) ≠ 0 ) |
| 50 | 49 | ancom2s 662 |
. . . . . . . 8
⊢ (((𝑅 ∈ Ring ∧ 𝑏 ∈ (𝐵 ∖ { 0 })) ∧ (∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 ∧ 𝑎 ∈ (𝐵 ∖ { 0 }))) → (𝑎 · 𝑏) ≠ 0 ) |
| 51 | 23, 50 | sylan2 604 |
. . . . . . 7
⊢ (((𝑅 ∈ Ring ∧ 𝑏 ∈ (𝐵 ∖ { 0 })) ∧ (∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ∧ 𝑎 ∈ (𝐵 ∖ { 0 }))) → (𝑎 · 𝑏) ≠ 0 ) |
| 52 | 51 | an42s 673 |
. . . . . 6
⊢ (((𝑅 ∈ Ring ∧ ∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ) ∧ (𝑎 ∈ (𝐵 ∖ { 0 }) ∧ 𝑏 ∈ (𝐵 ∖ { 0 }))) → (𝑎 · 𝑏) ≠ 0 ) |
| 53 | 52 | exp32 425 |
. . . . 5
⊢ ((𝑅 ∈ Ring ∧ ∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ) → (𝑎 ∈ (𝐵 ∖ { 0 }) → (𝑏 ∈ (𝐵 ∖ { 0 }) → (𝑎 · 𝑏) ≠ 0 ))) |
| 54 | 53 | 3adant2 1149 |
. . . 4
⊢ ((𝑅 ∈ Ring ∧ 1 ≠ 0 ∧
∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ) → (𝑎 ∈ (𝐵 ∖ { 0 }) → (𝑏 ∈ (𝐵 ∖ { 0 }) → (𝑎 · 𝑏) ≠ 0 ))) |
| 55 | 54 | 3imp 1128 |
. . 3
⊢ (((𝑅 ∈ Ring ∧ 1 ≠ 0 ∧
∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ) ∧ 𝑎 ∈ (𝐵 ∖ { 0 }) ∧ 𝑏 ∈ (𝐵 ∖ { 0 })) → (𝑎 · 𝑏) ≠ 0 ) |
| 56 | 18, 55 | eldifsnd 4755 |
. 2
⊢ (((𝑅 ∈ Ring ∧ 1 ≠ 0 ∧
∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ) ∧ 𝑎 ∈ (𝐵 ∖ { 0 }) ∧ 𝑏 ∈ (𝐵 ∖ { 0 })) → (𝑎 · 𝑏) ∈ (𝐵 ∖ { 0 })) |
| 57 | | eldifi 4085 |
. . . 4
⊢ (𝑐 ∈ (𝐵 ∖ { 0 }) → 𝑐 ∈ 𝐵) |
| 58 | 15, 16, 57 | 3anim123i 1169 |
. . 3
⊢ ((𝑎 ∈ (𝐵 ∖ { 0 }) ∧ 𝑏 ∈ (𝐵 ∖ { 0 }) ∧ 𝑐 ∈ (𝐵 ∖ { 0 })) → (𝑎 ∈ 𝐵 ∧ 𝑏 ∈ 𝐵 ∧ 𝑐 ∈ 𝐵)) |
| 59 | 1, 10 | ringass 20330 |
. . 3
⊢ ((𝑅 ∈ Ring ∧ (𝑎 ∈ 𝐵 ∧ 𝑏 ∈ 𝐵 ∧ 𝑐 ∈ 𝐵)) → ((𝑎 · 𝑏) · 𝑐) = (𝑎 · (𝑏 · 𝑐))) |
| 60 | 14, 58, 59 | syl2an 607 |
. 2
⊢ (((𝑅 ∈ Ring ∧ 1 ≠ 0 ∧
∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ) ∧ (𝑎 ∈ (𝐵 ∖ { 0 }) ∧ 𝑏 ∈ (𝐵 ∖ { 0 }) ∧ 𝑐 ∈ (𝐵 ∖ { 0 }))) → ((𝑎 · 𝑏) · 𝑐) = (𝑎 · (𝑏 · 𝑐))) |
| 61 | 1, 25 | ringidcl 20344 |
. . . . 5
⊢ (𝑅 ∈ Ring → 1 ∈ 𝐵) |
| 62 | | nelsn 4632 |
. . . . 5
⊢ ( 1 ≠ 0 → ¬
1 ∈
{ 0
}) |
| 63 | 61, 62 | anim12i 624 |
. . . 4
⊢ ((𝑅 ∈ Ring ∧ 1 ≠ 0 ) → (
1 ∈
𝐵 ∧ ¬ 1 ∈ {
0
})) |
| 64 | | eldif 3915 |
. . . 4
⊢ ( 1 ∈ (𝐵 ∖ { 0 }) ↔ ( 1 ∈ 𝐵 ∧ ¬ 1 ∈ { 0
})) |
| 65 | 63, 64 | sylibr 237 |
. . 3
⊢ ((𝑅 ∈ Ring ∧ 1 ≠ 0 ) →
1 ∈
(𝐵 ∖ { 0
})) |
| 66 | 65 | 3adant3 1150 |
. 2
⊢ ((𝑅 ∈ Ring ∧ 1 ≠ 0 ∧
∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ) → 1 ∈ (𝐵 ∖ { 0 })) |
| 67 | 1, 10, 25 | ringlidm 20348 |
. . 3
⊢ ((𝑅 ∈ Ring ∧ 𝑎 ∈ 𝐵) → ( 1 · 𝑎) = 𝑎) |
| 68 | 14, 15, 67 | syl2an 607 |
. 2
⊢ (((𝑅 ∈ Ring ∧ 1 ≠ 0 ∧
∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ) ∧ 𝑎 ∈ (𝐵 ∖ { 0 })) → ( 1 · 𝑎) = 𝑎) |
| 69 | | oveq1 7417 |
. . . . . . . 8
⊢ (𝑦 = 𝑏 → (𝑦 · 𝑎) = (𝑏 · 𝑎)) |
| 70 | 69 | eqeq1d 2765 |
. . . . . . 7
⊢ (𝑦 = 𝑏 → ((𝑦 · 𝑎) = 1 ↔ (𝑏 · 𝑎) = 1 )) |
| 71 | 70 | cbvrexvw 3244 |
. . . . . 6
⊢
(∃𝑦 ∈
(𝐵 ∖ { 0 })(𝑦 · 𝑎) = 1 ↔ ∃𝑏 ∈ (𝐵 ∖ { 0 })(𝑏 · 𝑎) = 1 ) |
| 72 | 21, 71 | bitrdi 290 |
. . . . 5
⊢ (𝑥 = 𝑎 → (∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ↔ ∃𝑏 ∈ (𝐵 ∖ { 0 })(𝑏 · 𝑎) = 1 )) |
| 73 | 72 | rspccv 3578 |
. . . 4
⊢
(∀𝑥 ∈
(𝐵 ∖ { 0
})∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 → (𝑎 ∈ (𝐵 ∖ { 0 }) → ∃𝑏 ∈ (𝐵 ∖ { 0 })(𝑏 · 𝑎) = 1 )) |
| 74 | 73 | 3ad2ant3 1153 |
. . 3
⊢ ((𝑅 ∈ Ring ∧ 1 ≠ 0 ∧
∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ) → (𝑎 ∈ (𝐵 ∖ { 0 }) → ∃𝑏 ∈ (𝐵 ∖ { 0 })(𝑏 · 𝑎) = 1 )) |
| 75 | 74 | imp 411 |
. 2
⊢ (((𝑅 ∈ Ring ∧ 1 ≠ 0 ∧
∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ) ∧ 𝑎 ∈ (𝐵 ∖ { 0 })) → ∃𝑏 ∈ (𝐵 ∖ { 0 })(𝑏 · 𝑎) = 1 ) |
| 76 | 4, 13, 56, 60, 66, 68, 75 | isgrpde 19019 |
1
⊢ ((𝑅 ∈ Ring ∧ 1 ≠ 0 ∧
∀𝑥 ∈ (𝐵 ∖ { 0 })∃𝑦 ∈ (𝐵 ∖ { 0 })(𝑦 · 𝑥) = 1 ) →
((mulGrp‘𝑅)
↾s (𝐵
∖ { 0 })) ∈
Grp) |