Proof of Theorem islssmd
| Step | Hyp | Ref
 | Expression | 
| 1 |   | islssd.u | 
. . . 4
⊢ (𝜑 → 𝑈 ⊆ 𝑉) | 
| 2 |   | islssd.v | 
. . . 4
⊢ (𝜑 → 𝑉 = (Base‘𝑊)) | 
| 3 | 1, 2 | sseqtrd 3221 | 
. . 3
⊢ (𝜑 → 𝑈 ⊆ (Base‘𝑊)) | 
| 4 |   | islssmd.m | 
. . 3
⊢ (𝜑 → ∃𝑗 𝑗 ∈ 𝑈) | 
| 5 |   | islssd.c | 
. . . . . . . . 9
⊢ ((𝜑 ∧ (𝑥 ∈ 𝐵 ∧ 𝑎 ∈ 𝑈 ∧ 𝑏 ∈ 𝑈)) → ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈) | 
| 6 | 5 | 3exp2 1227 | 
. . . . . . . 8
⊢ (𝜑 → (𝑥 ∈ 𝐵 → (𝑎 ∈ 𝑈 → (𝑏 ∈ 𝑈 → ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈)))) | 
| 7 | 6 | imp43 355 | 
. . . . . . 7
⊢ (((𝜑 ∧ 𝑥 ∈ 𝐵) ∧ (𝑎 ∈ 𝑈 ∧ 𝑏 ∈ 𝑈)) → ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈) | 
| 8 | 7 | ralrimivva 2579 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐵) → ∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈) | 
| 9 | 8 | ex 115 | 
. . . . 5
⊢ (𝜑 → (𝑥 ∈ 𝐵 → ∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈)) | 
| 10 |   | islssd.b | 
. . . . . . 7
⊢ (𝜑 → 𝐵 = (Base‘𝐹)) | 
| 11 |   | islssd.f | 
. . . . . . . 8
⊢ (𝜑 → 𝐹 = (Scalar‘𝑊)) | 
| 12 | 11 | fveq2d 5562 | 
. . . . . . 7
⊢ (𝜑 → (Base‘𝐹) =
(Base‘(Scalar‘𝑊))) | 
| 13 | 10, 12 | eqtrd 2229 | 
. . . . . 6
⊢ (𝜑 → 𝐵 = (Base‘(Scalar‘𝑊))) | 
| 14 | 13 | eleq2d 2266 | 
. . . . 5
⊢ (𝜑 → (𝑥 ∈ 𝐵 ↔ 𝑥 ∈ (Base‘(Scalar‘𝑊)))) | 
| 15 |   | islssd.p | 
. . . . . . . . 9
⊢ (𝜑 → + =
(+g‘𝑊)) | 
| 16 | 15 | oveqd 5939 | 
. . . . . . . 8
⊢ (𝜑 → ((𝑥 · 𝑎) + 𝑏) = ((𝑥 · 𝑎)(+g‘𝑊)𝑏)) | 
| 17 |   | islssd.t | 
. . . . . . . . . 10
⊢ (𝜑 → · = (
·𝑠 ‘𝑊)) | 
| 18 | 17 | oveqd 5939 | 
. . . . . . . . 9
⊢ (𝜑 → (𝑥 · 𝑎) = (𝑥( ·𝑠
‘𝑊)𝑎)) | 
| 19 | 18 | oveq1d 5937 | 
. . . . . . . 8
⊢ (𝜑 → ((𝑥 · 𝑎)(+g‘𝑊)𝑏) = ((𝑥( ·𝑠
‘𝑊)𝑎)(+g‘𝑊)𝑏)) | 
| 20 | 16, 19 | eqtrd 2229 | 
. . . . . . 7
⊢ (𝜑 → ((𝑥 · 𝑎) + 𝑏) = ((𝑥( ·𝑠
‘𝑊)𝑎)(+g‘𝑊)𝑏)) | 
| 21 | 20 | eleq1d 2265 | 
. . . . . 6
⊢ (𝜑 → (((𝑥 · 𝑎) + 𝑏) ∈ 𝑈 ↔ ((𝑥( ·𝑠
‘𝑊)𝑎)(+g‘𝑊)𝑏) ∈ 𝑈)) | 
| 22 | 21 | 2ralbidv 2521 | 
. . . . 5
⊢ (𝜑 → (∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥 · 𝑎) + 𝑏) ∈ 𝑈 ↔ ∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥( ·𝑠
‘𝑊)𝑎)(+g‘𝑊)𝑏) ∈ 𝑈)) | 
| 23 | 9, 14, 22 | 3imtr3d 202 | 
. . . 4
⊢ (𝜑 → (𝑥 ∈ (Base‘(Scalar‘𝑊)) → ∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥( ·𝑠
‘𝑊)𝑎)(+g‘𝑊)𝑏) ∈ 𝑈)) | 
| 24 | 23 | ralrimiv 2569 | 
. . 3
⊢ (𝜑 → ∀𝑥 ∈ (Base‘(Scalar‘𝑊))∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥( ·𝑠
‘𝑊)𝑎)(+g‘𝑊)𝑏) ∈ 𝑈) | 
| 25 |   | islssmd.w | 
. . . 4
⊢ (𝜑 → 𝑊 ∈ 𝑋) | 
| 26 |   | eqid 2196 | 
. . . . 5
⊢
(Scalar‘𝑊) =
(Scalar‘𝑊) | 
| 27 |   | eqid 2196 | 
. . . . 5
⊢
(Base‘(Scalar‘𝑊)) = (Base‘(Scalar‘𝑊)) | 
| 28 |   | eqid 2196 | 
. . . . 5
⊢
(Base‘𝑊) =
(Base‘𝑊) | 
| 29 |   | eqid 2196 | 
. . . . 5
⊢
(+g‘𝑊) = (+g‘𝑊) | 
| 30 |   | eqid 2196 | 
. . . . 5
⊢ (
·𝑠 ‘𝑊) = ( ·𝑠
‘𝑊) | 
| 31 |   | eqid 2196 | 
. . . . 5
⊢
(LSubSp‘𝑊) =
(LSubSp‘𝑊) | 
| 32 | 26, 27, 28, 29, 30, 31 | islssmg 13914 | 
. . . 4
⊢ (𝑊 ∈ 𝑋 → (𝑈 ∈ (LSubSp‘𝑊) ↔ (𝑈 ⊆ (Base‘𝑊) ∧ ∃𝑗 𝑗 ∈ 𝑈 ∧ ∀𝑥 ∈ (Base‘(Scalar‘𝑊))∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥( ·𝑠
‘𝑊)𝑎)(+g‘𝑊)𝑏) ∈ 𝑈))) | 
| 33 | 25, 32 | syl 14 | 
. . 3
⊢ (𝜑 → (𝑈 ∈ (LSubSp‘𝑊) ↔ (𝑈 ⊆ (Base‘𝑊) ∧ ∃𝑗 𝑗 ∈ 𝑈 ∧ ∀𝑥 ∈ (Base‘(Scalar‘𝑊))∀𝑎 ∈ 𝑈 ∀𝑏 ∈ 𝑈 ((𝑥( ·𝑠
‘𝑊)𝑎)(+g‘𝑊)𝑏) ∈ 𝑈))) | 
| 34 | 3, 4, 24, 33 | mpbir3and 1182 | 
. 2
⊢ (𝜑 → 𝑈 ∈ (LSubSp‘𝑊)) | 
| 35 |   | islssd.s | 
. 2
⊢ (𝜑 → 𝑆 = (LSubSp‘𝑊)) | 
| 36 | 34, 35 | eleqtrrd 2276 | 
1
⊢ (𝜑 → 𝑈 ∈ 𝑆) |