| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | domnring 20708 | . . . . 5
⊢ (𝑅 ∈ Domn → 𝑅 ∈ Ring) | 
| 2 | 1 | adantl 481 | . . . 4
⊢ ((𝐵 ∈ Fin ∧ 𝑅 ∈ Domn) → 𝑅 ∈ Ring) | 
| 3 |  | domnnzr 20707 | . . . . . . . . . . 11
⊢ (𝑅 ∈ Domn → 𝑅 ∈ NzRing) | 
| 4 | 3 | adantl 481 | . . . . . . . . . 10
⊢ ((𝐵 ∈ Fin ∧ 𝑅 ∈ Domn) → 𝑅 ∈ NzRing) | 
| 5 |  | eqid 2736 | . . . . . . . . . . 11
⊢
(1r‘𝑅) = (1r‘𝑅) | 
| 6 |  | eqid 2736 | . . . . . . . . . . 11
⊢
(0g‘𝑅) = (0g‘𝑅) | 
| 7 | 5, 6 | nzrnz 20516 | . . . . . . . . . 10
⊢ (𝑅 ∈ NzRing →
(1r‘𝑅)
≠ (0g‘𝑅)) | 
| 8 | 4, 7 | syl 17 | . . . . . . . . 9
⊢ ((𝐵 ∈ Fin ∧ 𝑅 ∈ Domn) →
(1r‘𝑅)
≠ (0g‘𝑅)) | 
| 9 | 8 | neneqd 2944 | . . . . . . . 8
⊢ ((𝐵 ∈ Fin ∧ 𝑅 ∈ Domn) → ¬
(1r‘𝑅) =
(0g‘𝑅)) | 
| 10 |  | eqid 2736 | . . . . . . . . . 10
⊢
(Unit‘𝑅) =
(Unit‘𝑅) | 
| 11 | 10, 6, 5 | 0unit 20397 | . . . . . . . . 9
⊢ (𝑅 ∈ Ring →
((0g‘𝑅)
∈ (Unit‘𝑅)
↔ (1r‘𝑅) = (0g‘𝑅))) | 
| 12 | 2, 11 | syl 17 | . . . . . . . 8
⊢ ((𝐵 ∈ Fin ∧ 𝑅 ∈ Domn) →
((0g‘𝑅)
∈ (Unit‘𝑅)
↔ (1r‘𝑅) = (0g‘𝑅))) | 
| 13 | 9, 12 | mtbird 325 | . . . . . . 7
⊢ ((𝐵 ∈ Fin ∧ 𝑅 ∈ Domn) → ¬
(0g‘𝑅)
∈ (Unit‘𝑅)) | 
| 14 |  | disjsn 4710 | . . . . . . 7
⊢
(((Unit‘𝑅)
∩ {(0g‘𝑅)}) = ∅ ↔ ¬
(0g‘𝑅)
∈ (Unit‘𝑅)) | 
| 15 | 13, 14 | sylibr 234 | . . . . . 6
⊢ ((𝐵 ∈ Fin ∧ 𝑅 ∈ Domn) →
((Unit‘𝑅) ∩
{(0g‘𝑅)})
= ∅) | 
| 16 |  | fidomndrng.b | . . . . . . . 8
⊢ 𝐵 = (Base‘𝑅) | 
| 17 | 16, 10 | unitss 20377 | . . . . . . 7
⊢
(Unit‘𝑅)
⊆ 𝐵 | 
| 18 |  | reldisj 4452 | . . . . . . 7
⊢
((Unit‘𝑅)
⊆ 𝐵 →
(((Unit‘𝑅) ∩
{(0g‘𝑅)})
= ∅ ↔ (Unit‘𝑅) ⊆ (𝐵 ∖ {(0g‘𝑅)}))) | 
| 19 | 17, 18 | ax-mp 5 | . . . . . 6
⊢
(((Unit‘𝑅)
∩ {(0g‘𝑅)}) = ∅ ↔ (Unit‘𝑅) ⊆ (𝐵 ∖ {(0g‘𝑅)})) | 
| 20 | 15, 19 | sylib 218 | . . . . 5
⊢ ((𝐵 ∈ Fin ∧ 𝑅 ∈ Domn) →
(Unit‘𝑅) ⊆
(𝐵 ∖
{(0g‘𝑅)})) | 
| 21 |  | eqid 2736 | . . . . . . 7
⊢
(∥r‘𝑅) = (∥r‘𝑅) | 
| 22 |  | eqid 2736 | . . . . . . 7
⊢
(.r‘𝑅) = (.r‘𝑅) | 
| 23 |  | simplr 768 | . . . . . . 7
⊢ (((𝐵 ∈ Fin ∧ 𝑅 ∈ Domn) ∧ 𝑥 ∈ (𝐵 ∖ {(0g‘𝑅)})) → 𝑅 ∈ Domn) | 
| 24 |  | simpll 766 | . . . . . . 7
⊢ (((𝐵 ∈ Fin ∧ 𝑅 ∈ Domn) ∧ 𝑥 ∈ (𝐵 ∖ {(0g‘𝑅)})) → 𝐵 ∈ Fin) | 
| 25 |  | simpr 484 | . . . . . . 7
⊢ (((𝐵 ∈ Fin ∧ 𝑅 ∈ Domn) ∧ 𝑥 ∈ (𝐵 ∖ {(0g‘𝑅)})) → 𝑥 ∈ (𝐵 ∖ {(0g‘𝑅)})) | 
| 26 |  | eqid 2736 | . . . . . . 7
⊢ (𝑦 ∈ 𝐵 ↦ (𝑦(.r‘𝑅)𝑥)) = (𝑦 ∈ 𝐵 ↦ (𝑦(.r‘𝑅)𝑥)) | 
| 27 | 16, 6, 5, 21, 22, 23, 24, 25, 26 | fidomndrnglem 20774 | . . . . . 6
⊢ (((𝐵 ∈ Fin ∧ 𝑅 ∈ Domn) ∧ 𝑥 ∈ (𝐵 ∖ {(0g‘𝑅)})) → 𝑥(∥r‘𝑅)(1r‘𝑅)) | 
| 28 |  | eqid 2736 | . . . . . . . 8
⊢
(oppr‘𝑅) = (oppr‘𝑅) | 
| 29 | 28, 16 | opprbas 20342 | . . . . . . 7
⊢ 𝐵 =
(Base‘(oppr‘𝑅)) | 
| 30 | 28, 6 | oppr0 20350 | . . . . . . 7
⊢
(0g‘𝑅) =
(0g‘(oppr‘𝑅)) | 
| 31 | 28, 5 | oppr1 20351 | . . . . . . 7
⊢
(1r‘𝑅) =
(1r‘(oppr‘𝑅)) | 
| 32 |  | eqid 2736 | . . . . . . 7
⊢
(∥r‘(oppr‘𝑅)) =
(∥r‘(oppr‘𝑅)) | 
| 33 |  | eqid 2736 | . . . . . . 7
⊢
(.r‘(oppr‘𝑅)) =
(.r‘(oppr‘𝑅)) | 
| 34 | 28 | opprdomn 20719 | . . . . . . . 8
⊢ (𝑅 ∈ Domn →
(oppr‘𝑅) ∈ Domn) | 
| 35 | 23, 34 | syl 17 | . . . . . . 7
⊢ (((𝐵 ∈ Fin ∧ 𝑅 ∈ Domn) ∧ 𝑥 ∈ (𝐵 ∖ {(0g‘𝑅)})) →
(oppr‘𝑅) ∈ Domn) | 
| 36 |  | eqid 2736 | . . . . . . 7
⊢ (𝑦 ∈ 𝐵 ↦ (𝑦(.r‘(oppr‘𝑅))𝑥)) = (𝑦 ∈ 𝐵 ↦ (𝑦(.r‘(oppr‘𝑅))𝑥)) | 
| 37 | 29, 30, 31, 32, 33, 35, 24, 25, 36 | fidomndrnglem 20774 | . . . . . 6
⊢ (((𝐵 ∈ Fin ∧ 𝑅 ∈ Domn) ∧ 𝑥 ∈ (𝐵 ∖ {(0g‘𝑅)})) → 𝑥(∥r‘(oppr‘𝑅))(1r‘𝑅)) | 
| 38 | 10, 5, 21, 28, 32 | isunit 20374 | . . . . . 6
⊢ (𝑥 ∈ (Unit‘𝑅) ↔ (𝑥(∥r‘𝑅)(1r‘𝑅) ∧ 𝑥(∥r‘(oppr‘𝑅))(1r‘𝑅))) | 
| 39 | 27, 37, 38 | sylanbrc 583 | . . . . 5
⊢ (((𝐵 ∈ Fin ∧ 𝑅 ∈ Domn) ∧ 𝑥 ∈ (𝐵 ∖ {(0g‘𝑅)})) → 𝑥 ∈ (Unit‘𝑅)) | 
| 40 | 20, 39 | eqelssd 4004 | . . . 4
⊢ ((𝐵 ∈ Fin ∧ 𝑅 ∈ Domn) →
(Unit‘𝑅) = (𝐵 ∖
{(0g‘𝑅)})) | 
| 41 | 16, 10, 6 | isdrng 20734 | . . . 4
⊢ (𝑅 ∈ DivRing ↔ (𝑅 ∈ Ring ∧
(Unit‘𝑅) = (𝐵 ∖
{(0g‘𝑅)}))) | 
| 42 | 2, 40, 41 | sylanbrc 583 | . . 3
⊢ ((𝐵 ∈ Fin ∧ 𝑅 ∈ Domn) → 𝑅 ∈
DivRing) | 
| 43 | 42 | ex 412 | . 2
⊢ (𝐵 ∈ Fin → (𝑅 ∈ Domn → 𝑅 ∈
DivRing)) | 
| 44 |  | drngdomn 20750 | . 2
⊢ (𝑅 ∈ DivRing → 𝑅 ∈ Domn) | 
| 45 | 43, 44 | impbid1 225 | 1
⊢ (𝐵 ∈ Fin → (𝑅 ∈ Domn ↔ 𝑅 ∈
DivRing)) |