| Step | Hyp | Ref
 | Expression | 
| 1 |   | qusring2.u | 
. . . 4
⊢ (𝜑 → 𝑈 = (𝑅 /s ∼ )) | 
| 2 |   | qusring2.v | 
. . . 4
⊢ (𝜑 → 𝑉 = (Base‘𝑅)) | 
| 3 |   | eqid 2196 | 
. . . 4
⊢ (𝑢 ∈ 𝑉 ↦ [𝑢] ∼ ) = (𝑢 ∈ 𝑉 ↦ [𝑢] ∼ ) | 
| 4 |   | qusring2.r | 
. . . . 5
⊢ (𝜑 → ∼ Er 𝑉) | 
| 5 |   | basfn 12736 | 
. . . . . . 7
⊢ Base Fn
V | 
| 6 |   | qusring2.x | 
. . . . . . . 8
⊢ (𝜑 → 𝑅 ∈ Ring) | 
| 7 | 6 | elexd 2776 | 
. . . . . . 7
⊢ (𝜑 → 𝑅 ∈ V) | 
| 8 |   | funfvex 5575 | 
. . . . . . . 8
⊢ ((Fun
Base ∧ 𝑅 ∈ dom
Base) → (Base‘𝑅)
∈ V) | 
| 9 | 8 | funfni 5358 | 
. . . . . . 7
⊢ ((Base Fn
V ∧ 𝑅 ∈ V) →
(Base‘𝑅) ∈
V) | 
| 10 | 5, 7, 9 | sylancr 414 | 
. . . . . 6
⊢ (𝜑 → (Base‘𝑅) ∈ V) | 
| 11 | 2, 10 | eqeltrd 2273 | 
. . . . 5
⊢ (𝜑 → 𝑉 ∈ V) | 
| 12 |   | erex 6616 | 
. . . . 5
⊢ ( ∼ Er
𝑉 → (𝑉 ∈ V → ∼ ∈
V)) | 
| 13 | 4, 11, 12 | sylc 62 | 
. . . 4
⊢ (𝜑 → ∼ ∈
V) | 
| 14 | 1, 2, 3, 13, 6 | qusval 12966 | 
. . 3
⊢ (𝜑 → 𝑈 = ((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )
“s 𝑅)) | 
| 15 |   | qusring2.p | 
. . 3
⊢  + =
(+g‘𝑅) | 
| 16 |   | qusring2.t | 
. . 3
⊢  · =
(.r‘𝑅) | 
| 17 |   | qusring2.o | 
. . 3
⊢  1 =
(1r‘𝑅) | 
| 18 | 1, 2, 3, 13, 6 | quslem 12967 | 
. . 3
⊢ (𝜑 → (𝑢 ∈ 𝑉 ↦ [𝑢] ∼ ):𝑉–onto→(𝑉 / ∼ )) | 
| 19 | 6 | adantr 276 | 
. . . . . 6
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉)) → 𝑅 ∈ Ring) | 
| 20 |   | simprl 529 | 
. . . . . . 7
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉)) → 𝑥 ∈ 𝑉) | 
| 21 | 2 | adantr 276 | 
. . . . . . 7
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉)) → 𝑉 = (Base‘𝑅)) | 
| 22 | 20, 21 | eleqtrd 2275 | 
. . . . . 6
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉)) → 𝑥 ∈ (Base‘𝑅)) | 
| 23 |   | simprr 531 | 
. . . . . . 7
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉)) → 𝑦 ∈ 𝑉) | 
| 24 | 23, 21 | eleqtrd 2275 | 
. . . . . 6
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉)) → 𝑦 ∈ (Base‘𝑅)) | 
| 25 |   | eqid 2196 | 
. . . . . . 7
⊢
(Base‘𝑅) =
(Base‘𝑅) | 
| 26 | 25, 15 | ringacl 13586 | 
. . . . . 6
⊢ ((𝑅 ∈ Ring ∧ 𝑥 ∈ (Base‘𝑅) ∧ 𝑦 ∈ (Base‘𝑅)) → (𝑥 + 𝑦) ∈ (Base‘𝑅)) | 
| 27 | 19, 22, 24, 26 | syl3anc 1249 | 
. . . . 5
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉)) → (𝑥 + 𝑦) ∈ (Base‘𝑅)) | 
| 28 | 27, 21 | eleqtrrd 2276 | 
. . . 4
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉)) → (𝑥 + 𝑦) ∈ 𝑉) | 
| 29 |   | qusring2.e1 | 
. . . 4
⊢ (𝜑 → ((𝑎 ∼ 𝑝 ∧ 𝑏 ∼ 𝑞) → (𝑎 + 𝑏) ∼ (𝑝 + 𝑞))) | 
| 30 | 4, 11, 3, 28, 29 | ercpbl 12974 | 
. . 3
⊢ ((𝜑 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉) ∧ (𝑝 ∈ 𝑉 ∧ 𝑞 ∈ 𝑉)) → ((((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )‘𝑎) = ((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )‘𝑝) ∧ ((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )‘𝑏) = ((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )‘𝑞)) → ((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )‘(𝑎 + 𝑏)) = ((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )‘(𝑝 + 𝑞)))) | 
| 31 | 25, 16 | ringcl 13569 | 
. . . . . 6
⊢ ((𝑅 ∈ Ring ∧ 𝑥 ∈ (Base‘𝑅) ∧ 𝑦 ∈ (Base‘𝑅)) → (𝑥 · 𝑦) ∈ (Base‘𝑅)) | 
| 32 | 19, 22, 24, 31 | syl3anc 1249 | 
. . . . 5
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉)) → (𝑥 · 𝑦) ∈ (Base‘𝑅)) | 
| 33 | 32, 21 | eleqtrrd 2276 | 
. . . 4
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉)) → (𝑥 · 𝑦) ∈ 𝑉) | 
| 34 |   | qusring2.e2 | 
. . . 4
⊢ (𝜑 → ((𝑎 ∼ 𝑝 ∧ 𝑏 ∼ 𝑞) → (𝑎 · 𝑏) ∼ (𝑝 · 𝑞))) | 
| 35 | 4, 11, 3, 33, 34 | ercpbl 12974 | 
. . 3
⊢ ((𝜑 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉) ∧ (𝑝 ∈ 𝑉 ∧ 𝑞 ∈ 𝑉)) → ((((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )‘𝑎) = ((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )‘𝑝) ∧ ((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )‘𝑏) = ((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )‘𝑞)) → ((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )‘(𝑎 · 𝑏)) = ((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )‘(𝑝 · 𝑞)))) | 
| 36 | 14, 2, 15, 16, 17, 18, 30, 35, 6 | imasring 13620 | 
. 2
⊢ (𝜑 → (𝑈 ∈ Ring ∧ ((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )‘ 1 ) =
(1r‘𝑈))) | 
| 37 |   | ringsrg 13603 | 
. . . . . . . 8
⊢ (𝑅 ∈ Ring → 𝑅 ∈ SRing) | 
| 38 | 25, 17 | srgidcl 13532 | 
. . . . . . . 8
⊢ (𝑅 ∈ SRing → 1 ∈
(Base‘𝑅)) | 
| 39 | 6, 37, 38 | 3syl 17 | 
. . . . . . 7
⊢ (𝜑 → 1 ∈ (Base‘𝑅)) | 
| 40 | 39, 2 | eleqtrrd 2276 | 
. . . . . 6
⊢ (𝜑 → 1 ∈ 𝑉) | 
| 41 | 4, 11, 3, 40 | divsfvalg 12972 | 
. . . . 5
⊢ (𝜑 → ((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )‘ 1 ) = [ 1 ] ∼
) | 
| 42 | 41 | eqcomd 2202 | 
. . . 4
⊢ (𝜑 → [ 1 ] ∼ = ((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )‘ 1
)) | 
| 43 | 42 | eqeq1d 2205 | 
. . 3
⊢ (𝜑 → ([ 1 ] ∼ =
(1r‘𝑈)
↔ ((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )‘ 1 ) =
(1r‘𝑈))) | 
| 44 | 43 | anbi2d 464 | 
. 2
⊢ (𝜑 → ((𝑈 ∈ Ring ∧ [ 1 ] ∼ =
(1r‘𝑈))
↔ (𝑈 ∈ Ring ∧
((𝑢 ∈ 𝑉 ↦ [𝑢] ∼ )‘ 1 ) =
(1r‘𝑈)))) | 
| 45 | 36, 44 | mpbird 167 | 
1
⊢ (𝜑 → (𝑈 ∈ Ring ∧ [ 1 ] ∼ =
(1r‘𝑈))) |