| Step | Hyp | Ref
 | Expression | 
| 1 |   | df-subrng 13754 | 
. . 3
⊢ SubRng =
(𝑤 ∈ Rng ↦
{𝑠 ∈ 𝒫
(Base‘𝑤) ∣
(𝑤 ↾s
𝑠) ∈
Rng}) | 
| 2 | 1 | mptrcl 5644 | 
. 2
⊢ (𝐴 ∈ (SubRng‘𝑅) → 𝑅 ∈ Rng) | 
| 3 |   | simp1 999 | 
. 2
⊢ ((𝑅 ∈ Rng ∧ (𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ⊆ 𝐵) → 𝑅 ∈ Rng) | 
| 4 |   | df-subrng 13754 | 
. . . . 5
⊢ SubRng =
(𝑟 ∈ Rng ↦
{𝑠 ∈ 𝒫
(Base‘𝑟) ∣
(𝑟 ↾s
𝑠) ∈
Rng}) | 
| 5 |   | fveq2 5558 | 
. . . . . . 7
⊢ (𝑟 = 𝑅 → (Base‘𝑟) = (Base‘𝑅)) | 
| 6 | 5 | pweqd 3610 | 
. . . . . 6
⊢ (𝑟 = 𝑅 → 𝒫 (Base‘𝑟) = 𝒫 (Base‘𝑅)) | 
| 7 |   | oveq1 5929 | 
. . . . . . 7
⊢ (𝑟 = 𝑅 → (𝑟 ↾s 𝑠) = (𝑅 ↾s 𝑠)) | 
| 8 | 7 | eleq1d 2265 | 
. . . . . 6
⊢ (𝑟 = 𝑅 → ((𝑟 ↾s 𝑠) ∈ Rng ↔ (𝑅 ↾s 𝑠) ∈ Rng)) | 
| 9 | 6, 8 | rabeqbidv 2758 | 
. . . . 5
⊢ (𝑟 = 𝑅 → {𝑠 ∈ 𝒫 (Base‘𝑟) ∣ (𝑟 ↾s 𝑠) ∈ Rng} = {𝑠 ∈ 𝒫 (Base‘𝑅) ∣ (𝑅 ↾s 𝑠) ∈ Rng}) | 
| 10 |   | id 19 | 
. . . . 5
⊢ (𝑅 ∈ Rng → 𝑅 ∈ Rng) | 
| 11 |   | basfn 12736 | 
. . . . . . . 8
⊢ Base Fn
V | 
| 12 |   | elex 2774 | 
. . . . . . . 8
⊢ (𝑅 ∈ Rng → 𝑅 ∈ V) | 
| 13 |   | funfvex 5575 | 
. . . . . . . . 9
⊢ ((Fun
Base ∧ 𝑅 ∈ dom
Base) → (Base‘𝑅)
∈ V) | 
| 14 | 13 | funfni 5358 | 
. . . . . . . 8
⊢ ((Base Fn
V ∧ 𝑅 ∈ V) →
(Base‘𝑅) ∈
V) | 
| 15 | 11, 12, 14 | sylancr 414 | 
. . . . . . 7
⊢ (𝑅 ∈ Rng →
(Base‘𝑅) ∈
V) | 
| 16 | 15 | pwexd 4214 | 
. . . . . 6
⊢ (𝑅 ∈ Rng → 𝒫
(Base‘𝑅) ∈
V) | 
| 17 |   | rabexg 4176 | 
. . . . . 6
⊢
(𝒫 (Base‘𝑅) ∈ V → {𝑠 ∈ 𝒫 (Base‘𝑅) ∣ (𝑅 ↾s 𝑠) ∈ Rng} ∈ V) | 
| 18 | 16, 17 | syl 14 | 
. . . . 5
⊢ (𝑅 ∈ Rng → {𝑠 ∈ 𝒫
(Base‘𝑅) ∣
(𝑅 ↾s
𝑠) ∈ Rng} ∈
V) | 
| 19 | 4, 9, 10, 18 | fvmptd3 5655 | 
. . . 4
⊢ (𝑅 ∈ Rng →
(SubRng‘𝑅) = {𝑠 ∈ 𝒫
(Base‘𝑅) ∣
(𝑅 ↾s
𝑠) ∈
Rng}) | 
| 20 | 19 | eleq2d 2266 | 
. . 3
⊢ (𝑅 ∈ Rng → (𝐴 ∈ (SubRng‘𝑅) ↔ 𝐴 ∈ {𝑠 ∈ 𝒫 (Base‘𝑅) ∣ (𝑅 ↾s 𝑠) ∈ Rng})) | 
| 21 |   | oveq2 5930 | 
. . . . . 6
⊢ (𝑠 = 𝐴 → (𝑅 ↾s 𝑠) = (𝑅 ↾s 𝐴)) | 
| 22 | 21 | eleq1d 2265 | 
. . . . 5
⊢ (𝑠 = 𝐴 → ((𝑅 ↾s 𝑠) ∈ Rng ↔ (𝑅 ↾s 𝐴) ∈ Rng)) | 
| 23 | 22 | elrab 2920 | 
. . . 4
⊢ (𝐴 ∈ {𝑠 ∈ 𝒫 (Base‘𝑅) ∣ (𝑅 ↾s 𝑠) ∈ Rng} ↔ (𝐴 ∈ 𝒫 (Base‘𝑅) ∧ (𝑅 ↾s 𝐴) ∈ Rng)) | 
| 24 |   | issubrng.b | 
. . . . . . . . 9
⊢ 𝐵 = (Base‘𝑅) | 
| 25 | 24 | eqcomi 2200 | 
. . . . . . . 8
⊢
(Base‘𝑅) =
𝐵 | 
| 26 | 25 | sseq2i 3210 | 
. . . . . . 7
⊢ (𝐴 ⊆ (Base‘𝑅) ↔ 𝐴 ⊆ 𝐵) | 
| 27 | 26 | anbi2i 457 | 
. . . . . 6
⊢ (((𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ⊆ (Base‘𝑅)) ↔ ((𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ⊆ 𝐵)) | 
| 28 |   | ibar 301 | 
. . . . . 6
⊢ (𝑅 ∈ Rng → (((𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ⊆ 𝐵) ↔ (𝑅 ∈ Rng ∧ ((𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ⊆ 𝐵)))) | 
| 29 | 27, 28 | bitrid 192 | 
. . . . 5
⊢ (𝑅 ∈ Rng → (((𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ⊆ (Base‘𝑅)) ↔ (𝑅 ∈ Rng ∧ ((𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ⊆ 𝐵)))) | 
| 30 |   | ancom 266 | 
. . . . . 6
⊢ ((𝐴 ∈ 𝒫
(Base‘𝑅) ∧ (𝑅 ↾s 𝐴) ∈ Rng) ↔ ((𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ∈ 𝒫
(Base‘𝑅))) | 
| 31 |   | elpw2g 4189 | 
. . . . . . . 8
⊢
((Base‘𝑅)
∈ V → (𝐴 ∈
𝒫 (Base‘𝑅)
↔ 𝐴 ⊆
(Base‘𝑅))) | 
| 32 | 15, 31 | syl 14 | 
. . . . . . 7
⊢ (𝑅 ∈ Rng → (𝐴 ∈ 𝒫
(Base‘𝑅) ↔ 𝐴 ⊆ (Base‘𝑅))) | 
| 33 | 32 | anbi2d 464 | 
. . . . . 6
⊢ (𝑅 ∈ Rng → (((𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ∈ 𝒫
(Base‘𝑅)) ↔
((𝑅 ↾s
𝐴) ∈ Rng ∧ 𝐴 ⊆ (Base‘𝑅)))) | 
| 34 | 30, 33 | bitrid 192 | 
. . . . 5
⊢ (𝑅 ∈ Rng → ((𝐴 ∈ 𝒫
(Base‘𝑅) ∧ (𝑅 ↾s 𝐴) ∈ Rng) ↔ ((𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ⊆ (Base‘𝑅)))) | 
| 35 |   | 3anass 984 | 
. . . . . 6
⊢ ((𝑅 ∈ Rng ∧ (𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ⊆ 𝐵) ↔ (𝑅 ∈ Rng ∧ ((𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ⊆ 𝐵))) | 
| 36 | 35 | a1i 9 | 
. . . . 5
⊢ (𝑅 ∈ Rng → ((𝑅 ∈ Rng ∧ (𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ⊆ 𝐵) ↔ (𝑅 ∈ Rng ∧ ((𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ⊆ 𝐵)))) | 
| 37 | 29, 34, 36 | 3bitr4d 220 | 
. . . 4
⊢ (𝑅 ∈ Rng → ((𝐴 ∈ 𝒫
(Base‘𝑅) ∧ (𝑅 ↾s 𝐴) ∈ Rng) ↔ (𝑅 ∈ Rng ∧ (𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ⊆ 𝐵))) | 
| 38 | 23, 37 | bitrid 192 | 
. . 3
⊢ (𝑅 ∈ Rng → (𝐴 ∈ {𝑠 ∈ 𝒫 (Base‘𝑅) ∣ (𝑅 ↾s 𝑠) ∈ Rng} ↔ (𝑅 ∈ Rng ∧ (𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ⊆ 𝐵))) | 
| 39 | 20, 38 | bitrd 188 | 
. 2
⊢ (𝑅 ∈ Rng → (𝐴 ∈ (SubRng‘𝑅) ↔ (𝑅 ∈ Rng ∧ (𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ⊆ 𝐵))) | 
| 40 | 2, 3, 39 | pm5.21nii 705 | 
1
⊢ (𝐴 ∈ (SubRng‘𝑅) ↔ (𝑅 ∈ Rng ∧ (𝑅 ↾s 𝐴) ∈ Rng ∧ 𝐴 ⊆ 𝐵)) |