| Step | Hyp | Ref
 | Expression | 
| 1 |   | lssset.s | 
. 2
⊢ 𝑆 = (LSubSp‘𝑊) | 
| 2 |   | df-lssm 13909 | 
. . 3
⊢ LSubSp =
(𝑤 ∈ V ↦ {𝑠 ∈ 𝒫
(Base‘𝑤) ∣
(∃𝑗 𝑗 ∈ 𝑠 ∧ ∀𝑥 ∈ (Base‘(Scalar‘𝑤))∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥( ·𝑠
‘𝑤)𝑎)(+g‘𝑤)𝑏) ∈ 𝑠)}) | 
| 3 |   | fveq2 5558 | 
. . . . . 6
⊢ (𝑤 = 𝑊 → (Base‘𝑤) = (Base‘𝑊)) | 
| 4 |   | lssset.v | 
. . . . . 6
⊢ 𝑉 = (Base‘𝑊) | 
| 5 | 3, 4 | eqtr4di 2247 | 
. . . . 5
⊢ (𝑤 = 𝑊 → (Base‘𝑤) = 𝑉) | 
| 6 | 5 | pweqd 3610 | 
. . . 4
⊢ (𝑤 = 𝑊 → 𝒫 (Base‘𝑤) = 𝒫 𝑉) | 
| 7 |   | fveq2 5558 | 
. . . . . . . . 9
⊢ (𝑤 = 𝑊 → (Scalar‘𝑤) = (Scalar‘𝑊)) | 
| 8 |   | lssset.f | 
. . . . . . . . 9
⊢ 𝐹 = (Scalar‘𝑊) | 
| 9 | 7, 8 | eqtr4di 2247 | 
. . . . . . . 8
⊢ (𝑤 = 𝑊 → (Scalar‘𝑤) = 𝐹) | 
| 10 | 9 | fveq2d 5562 | 
. . . . . . 7
⊢ (𝑤 = 𝑊 → (Base‘(Scalar‘𝑤)) = (Base‘𝐹)) | 
| 11 |   | lssset.b | 
. . . . . . 7
⊢ 𝐵 = (Base‘𝐹) | 
| 12 | 10, 11 | eqtr4di 2247 | 
. . . . . 6
⊢ (𝑤 = 𝑊 → (Base‘(Scalar‘𝑤)) = 𝐵) | 
| 13 |   | fveq2 5558 | 
. . . . . . . . . . . 12
⊢ (𝑤 = 𝑊 → (
·𝑠 ‘𝑤) = ( ·𝑠
‘𝑊)) | 
| 14 |   | lssset.t | 
. . . . . . . . . . . 12
⊢  · = (
·𝑠 ‘𝑊) | 
| 15 | 13, 14 | eqtr4di 2247 | 
. . . . . . . . . . 11
⊢ (𝑤 = 𝑊 → (
·𝑠 ‘𝑤) = · ) | 
| 16 | 15 | oveqd 5939 | 
. . . . . . . . . 10
⊢ (𝑤 = 𝑊 → (𝑥( ·𝑠
‘𝑤)𝑎) = (𝑥 · 𝑎)) | 
| 17 | 16 | oveq1d 5937 | 
. . . . . . . . 9
⊢ (𝑤 = 𝑊 → ((𝑥( ·𝑠
‘𝑤)𝑎)(+g‘𝑤)𝑏) = ((𝑥 · 𝑎)(+g‘𝑤)𝑏)) | 
| 18 |   | fveq2 5558 | 
. . . . . . . . . . 11
⊢ (𝑤 = 𝑊 → (+g‘𝑤) = (+g‘𝑊)) | 
| 19 |   | lssset.p | 
. . . . . . . . . . 11
⊢  + =
(+g‘𝑊) | 
| 20 | 18, 19 | eqtr4di 2247 | 
. . . . . . . . . 10
⊢ (𝑤 = 𝑊 → (+g‘𝑤) = + ) | 
| 21 | 20 | oveqd 5939 | 
. . . . . . . . 9
⊢ (𝑤 = 𝑊 → ((𝑥 · 𝑎)(+g‘𝑤)𝑏) = ((𝑥 · 𝑎) + 𝑏)) | 
| 22 | 17, 21 | eqtrd 2229 | 
. . . . . . . 8
⊢ (𝑤 = 𝑊 → ((𝑥( ·𝑠
‘𝑤)𝑎)(+g‘𝑤)𝑏) = ((𝑥 · 𝑎) + 𝑏)) | 
| 23 | 22 | eleq1d 2265 | 
. . . . . . 7
⊢ (𝑤 = 𝑊 → (((𝑥( ·𝑠
‘𝑤)𝑎)(+g‘𝑤)𝑏) ∈ 𝑠 ↔ ((𝑥 · 𝑎) + 𝑏) ∈ 𝑠)) | 
| 24 | 23 | 2ralbidv 2521 | 
. . . . . 6
⊢ (𝑤 = 𝑊 → (∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥( ·𝑠
‘𝑤)𝑎)(+g‘𝑤)𝑏) ∈ 𝑠 ↔ ∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑠)) | 
| 25 | 12, 24 | raleqbidv 2709 | 
. . . . 5
⊢ (𝑤 = 𝑊 → (∀𝑥 ∈ (Base‘(Scalar‘𝑤))∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥( ·𝑠
‘𝑤)𝑎)(+g‘𝑤)𝑏) ∈ 𝑠 ↔ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑠)) | 
| 26 | 25 | anbi2d 464 | 
. . . 4
⊢ (𝑤 = 𝑊 → ((∃𝑗 𝑗 ∈ 𝑠 ∧ ∀𝑥 ∈ (Base‘(Scalar‘𝑤))∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥( ·𝑠
‘𝑤)𝑎)(+g‘𝑤)𝑏) ∈ 𝑠) ↔ (∃𝑗 𝑗 ∈ 𝑠 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑠))) | 
| 27 | 6, 26 | rabeqbidv 2758 | 
. . 3
⊢ (𝑤 = 𝑊 → {𝑠 ∈ 𝒫 (Base‘𝑤) ∣ (∃𝑗 𝑗 ∈ 𝑠 ∧ ∀𝑥 ∈ (Base‘(Scalar‘𝑤))∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥( ·𝑠
‘𝑤)𝑎)(+g‘𝑤)𝑏) ∈ 𝑠)} = {𝑠 ∈ 𝒫 𝑉 ∣ (∃𝑗 𝑗 ∈ 𝑠 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑠)}) | 
| 28 |   | elex 2774 | 
. . 3
⊢ (𝑊 ∈ 𝑋 → 𝑊 ∈ V) | 
| 29 |   | basfn 12736 | 
. . . . . . 7
⊢ Base Fn
V | 
| 30 |   | funfvex 5575 | 
. . . . . . . 8
⊢ ((Fun
Base ∧ 𝑊 ∈ dom
Base) → (Base‘𝑊)
∈ V) | 
| 31 | 30 | funfni 5358 | 
. . . . . . 7
⊢ ((Base Fn
V ∧ 𝑊 ∈ V) →
(Base‘𝑊) ∈
V) | 
| 32 | 29, 28, 31 | sylancr 414 | 
. . . . . 6
⊢ (𝑊 ∈ 𝑋 → (Base‘𝑊) ∈ V) | 
| 33 | 4, 32 | eqeltrid 2283 | 
. . . . 5
⊢ (𝑊 ∈ 𝑋 → 𝑉 ∈ V) | 
| 34 | 33 | pwexd 4214 | 
. . . 4
⊢ (𝑊 ∈ 𝑋 → 𝒫 𝑉 ∈ V) | 
| 35 |   | rabexg 4176 | 
. . . 4
⊢
(𝒫 𝑉 ∈
V → {𝑠 ∈
𝒫 𝑉 ∣
(∃𝑗 𝑗 ∈ 𝑠 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑠)} ∈ V) | 
| 36 | 34, 35 | syl 14 | 
. . 3
⊢ (𝑊 ∈ 𝑋 → {𝑠 ∈ 𝒫 𝑉 ∣ (∃𝑗 𝑗 ∈ 𝑠 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑠)} ∈ V) | 
| 37 | 2, 27, 28, 36 | fvmptd3 5655 | 
. 2
⊢ (𝑊 ∈ 𝑋 → (LSubSp‘𝑊) = {𝑠 ∈ 𝒫 𝑉 ∣ (∃𝑗 𝑗 ∈ 𝑠 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑠)}) | 
| 38 | 1, 37 | eqtrid 2241 | 
1
⊢ (𝑊 ∈ 𝑋 → 𝑆 = {𝑠 ∈ 𝒫 𝑉 ∣ (∃𝑗 𝑗 ∈ 𝑠 ∧ ∀𝑥 ∈ 𝐵 ∀𝑎 ∈ 𝑠 ∀𝑏 ∈ 𝑠 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑠)}) |