| Step | Hyp | Ref
 | Expression | 
| 1 |   | lssset.s | 
. . 3
⊢ 𝑆 = (LSubSp‘𝑊) | 
| 2 | 1 | lssmex 13911 | 
. 2
⊢ (𝑈 ∈ 𝑆 → 𝑊 ∈ V) | 
| 3 |   | eleq1w 2257 | 
. . . . . 6
⊢ (𝑘 = 𝑗 → (𝑘 ∈ 𝑈 ↔ 𝑗 ∈ 𝑈)) | 
| 4 | 3 | cbvexv 1933 | 
. . . . 5
⊢
(∃𝑘 𝑘 ∈ 𝑈 ↔ ∃𝑗 𝑗 ∈ 𝑈) | 
| 5 |   | ssel 3177 | 
. . . . . . 7
⊢ (𝑈 ⊆ 𝑉 → (𝑘 ∈ 𝑈 → 𝑘 ∈ 𝑉)) | 
| 6 |   | lssset.v | 
. . . . . . . 8
⊢ 𝑉 = (Base‘𝑊) | 
| 7 | 6 | basmex 12737 | 
. . . . . . 7
⊢ (𝑘 ∈ 𝑉 → 𝑊 ∈ V) | 
| 8 | 5, 7 | syl6 33 | 
. . . . . 6
⊢ (𝑈 ⊆ 𝑉 → (𝑘 ∈ 𝑈 → 𝑊 ∈ V)) | 
| 9 | 8 | exlimdv 1833 | 
. . . . 5
⊢ (𝑈 ⊆ 𝑉 → (∃𝑘 𝑘 ∈ 𝑈 → 𝑊 ∈ V)) | 
| 10 | 4, 9 | biimtrrid 153 | 
. . . 4
⊢ (𝑈 ⊆ 𝑉 → (∃𝑗 𝑗 ∈ 𝑈 → 𝑊 ∈ V)) | 
| 11 | 10 | imp 124 | 
. . 3
⊢ ((𝑈 ⊆ 𝑉 ∧ ∃𝑗 𝑗 ∈ 𝑈) → 𝑊 ∈ V) | 
| 12 | 11 | 3adant3 1019 | 
. 2
⊢ ((𝑈 ⊆ 𝑉 ∧ ∃𝑗 𝑗 ∈ 𝑈 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈) → 𝑊 ∈ V) | 
| 13 |   | lssset.f | 
. . . . 5
⊢ 𝐹 = (Scalar‘𝑊) | 
| 14 |   | lssset.b | 
. . . . 5
⊢ 𝐵 = (Base‘𝐹) | 
| 15 |   | lssset.p | 
. . . . 5
⊢  + =
(+g‘𝑊) | 
| 16 |   | lssset.t | 
. . . . 5
⊢  · = (
·𝑠 ‘𝑊) | 
| 17 | 13, 14, 6, 15, 16, 1 | lsssetm 13912 | 
. . . 4
⊢ (𝑊 ∈ V → 𝑆 = {𝑠 ∈ 𝒫 𝑉 ∣ (∃𝑗 𝑗 ∈ 𝑠 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑠)}) | 
| 18 | 17 | eleq2d 2266 | 
. . 3
⊢ (𝑊 ∈ V → (𝑈 ∈ 𝑆 ↔ 𝑈 ∈ {𝑠 ∈ 𝒫 𝑉 ∣ (∃𝑗 𝑗 ∈ 𝑠 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑠)})) | 
| 19 |   | basfn 12736 | 
. . . . . . . 8
⊢ Base Fn
V | 
| 20 |   | funfvex 5575 | 
. . . . . . . . 9
⊢ ((Fun
Base ∧ 𝑊 ∈ dom
Base) → (Base‘𝑊)
∈ V) | 
| 21 | 20 | funfni 5358 | 
. . . . . . . 8
⊢ ((Base Fn
V ∧ 𝑊 ∈ V) →
(Base‘𝑊) ∈
V) | 
| 22 | 19, 21 | mpan 424 | 
. . . . . . 7
⊢ (𝑊 ∈ V →
(Base‘𝑊) ∈
V) | 
| 23 | 6, 22 | eqeltrid 2283 | 
. . . . . 6
⊢ (𝑊 ∈ V → 𝑉 ∈ V) | 
| 24 |   | elpw2g 4189 | 
. . . . . 6
⊢ (𝑉 ∈ V → (𝑈 ∈ 𝒫 𝑉 ↔ 𝑈 ⊆ 𝑉)) | 
| 25 | 23, 24 | syl 14 | 
. . . . 5
⊢ (𝑊 ∈ V → (𝑈 ∈ 𝒫 𝑉 ↔ 𝑈 ⊆ 𝑉)) | 
| 26 | 25 | anbi1d 465 | 
. . . 4
⊢ (𝑊 ∈ V → ((𝑈 ∈ 𝒫 𝑉 ∧ (∃𝑗 𝑗 ∈ 𝑈 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈)) ↔ (𝑈 ⊆ 𝑉 ∧ (∃𝑗 𝑗 ∈ 𝑈 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈)))) | 
| 27 |   | eleq2 2260 | 
. . . . . . 7
⊢ (𝑠 = 𝑈 → (𝑗 ∈ 𝑠 ↔ 𝑗 ∈ 𝑈)) | 
| 28 | 27 | exbidv 1839 | 
. . . . . 6
⊢ (𝑠 = 𝑈 → (∃𝑗 𝑗 ∈ 𝑠 ↔ ∃𝑗 𝑗 ∈ 𝑈)) | 
| 29 |   | eleq2 2260 | 
. . . . . . . . 9
⊢ (𝑠 = 𝑈 → (((𝑥 · 𝑎) + 𝑏) ∈ 𝑠 ↔ ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈)) | 
| 30 | 29 | raleqbi1dv 2705 | 
. . . . . . . 8
⊢ (𝑠 = 𝑈 → (∀𝑏 ∈ 𝑠 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑠 ↔ ∀𝑏 ∈ 𝑈 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈)) | 
| 31 | 30 | raleqbi1dv 2705 | 
. . . . . . 7
⊢ (𝑠 = 𝑈 → (∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑠 ↔ ∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈)) | 
| 32 | 31 | ralbidv 2497 | 
. . . . . 6
⊢ (𝑠 = 𝑈 → (∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑠 ↔ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈)) | 
| 33 | 28, 32 | anbi12d 473 | 
. . . . 5
⊢ (𝑠 = 𝑈 → ((∃𝑗 𝑗 ∈ 𝑠 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑠) ↔ (∃𝑗 𝑗 ∈ 𝑈 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈))) | 
| 34 | 33 | elrab 2920 | 
. . . 4
⊢ (𝑈 ∈ {𝑠 ∈ 𝒫 𝑉 ∣ (∃𝑗 𝑗 ∈ 𝑠 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑠)} ↔ (𝑈 ∈ 𝒫 𝑉 ∧ (∃𝑗 𝑗 ∈ 𝑈 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈))) | 
| 35 |   | 3anass 984 | 
. . . 4
⊢ ((𝑈 ⊆ 𝑉 ∧ ∃𝑗 𝑗 ∈ 𝑈 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈) ↔ (𝑈 ⊆ 𝑉 ∧ (∃𝑗 𝑗 ∈ 𝑈 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈))) | 
| 36 | 26, 34, 35 | 3bitr4g 223 | 
. . 3
⊢ (𝑊 ∈ V → (𝑈 ∈ {𝑠 ∈ 𝒫 𝑉 ∣ (∃𝑗 𝑗 ∈ 𝑠 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑠)} ↔ (𝑈 ⊆ 𝑉 ∧ ∃𝑗 𝑗 ∈ 𝑈 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈))) | 
| 37 | 18, 36 | bitrd 188 | 
. 2
⊢ (𝑊 ∈ V → (𝑈 ∈ 𝑆 ↔ (𝑈 ⊆ 𝑉 ∧ ∃𝑗 𝑗 ∈ 𝑈 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈))) | 
| 38 | 2, 12, 37 | pm5.21nii 705 | 
1
⊢ (𝑈 ∈ 𝑆 ↔ (𝑈 ⊆ 𝑉 ∧ ∃𝑗 𝑗 ∈ 𝑈 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈)) |