Proof of Theorem lmodsubdir
| Step | Hyp | Ref
 | Expression | 
| 1 |   | lmodsubdir.w | 
. . . 4
⊢ (𝜑 → 𝑊 ∈ LMod) | 
| 2 |   | lmodsubdir.a | 
. . . 4
⊢ (𝜑 → 𝐴 ∈ 𝐾) | 
| 3 |   | lmodsubdir.f | 
. . . . . . . 8
⊢ 𝐹 = (Scalar‘𝑊) | 
| 4 | 3 | lmodring 13851 | 
. . . . . . 7
⊢ (𝑊 ∈ LMod → 𝐹 ∈ Ring) | 
| 5 | 1, 4 | syl 14 | 
. . . . . 6
⊢ (𝜑 → 𝐹 ∈ Ring) | 
| 6 |   | ringgrp 13557 | 
. . . . . 6
⊢ (𝐹 ∈ Ring → 𝐹 ∈ Grp) | 
| 7 | 5, 6 | syl 14 | 
. . . . 5
⊢ (𝜑 → 𝐹 ∈ Grp) | 
| 8 |   | lmodsubdir.b | 
. . . . 5
⊢ (𝜑 → 𝐵 ∈ 𝐾) | 
| 9 |   | lmodsubdir.k | 
. . . . . 6
⊢ 𝐾 = (Base‘𝐹) | 
| 10 |   | eqid 2196 | 
. . . . . 6
⊢
(invg‘𝐹) = (invg‘𝐹) | 
| 11 | 9, 10 | grpinvcl 13180 | 
. . . . 5
⊢ ((𝐹 ∈ Grp ∧ 𝐵 ∈ 𝐾) → ((invg‘𝐹)‘𝐵) ∈ 𝐾) | 
| 12 | 7, 8, 11 | syl2anc 411 | 
. . . 4
⊢ (𝜑 →
((invg‘𝐹)‘𝐵) ∈ 𝐾) | 
| 13 |   | lmodsubdir.x | 
. . . 4
⊢ (𝜑 → 𝑋 ∈ 𝑉) | 
| 14 |   | lmodsubdir.v | 
. . . . 5
⊢ 𝑉 = (Base‘𝑊) | 
| 15 |   | eqid 2196 | 
. . . . 5
⊢
(+g‘𝑊) = (+g‘𝑊) | 
| 16 |   | lmodsubdir.t | 
. . . . 5
⊢  · = (
·𝑠 ‘𝑊) | 
| 17 |   | eqid 2196 | 
. . . . 5
⊢
(+g‘𝐹) = (+g‘𝐹) | 
| 18 | 14, 15, 3, 16, 9, 17 | lmodvsdir 13868 | 
. . . 4
⊢ ((𝑊 ∈ LMod ∧ (𝐴 ∈ 𝐾 ∧ ((invg‘𝐹)‘𝐵) ∈ 𝐾 ∧ 𝑋 ∈ 𝑉)) → ((𝐴(+g‘𝐹)((invg‘𝐹)‘𝐵)) · 𝑋) = ((𝐴 · 𝑋)(+g‘𝑊)(((invg‘𝐹)‘𝐵) · 𝑋))) | 
| 19 | 1, 2, 12, 13, 18 | syl13anc 1251 | 
. . 3
⊢ (𝜑 → ((𝐴(+g‘𝐹)((invg‘𝐹)‘𝐵)) · 𝑋) = ((𝐴 · 𝑋)(+g‘𝑊)(((invg‘𝐹)‘𝐵) · 𝑋))) | 
| 20 |   | eqid 2196 | 
. . . . . . 7
⊢
(.r‘𝐹) = (.r‘𝐹) | 
| 21 |   | eqid 2196 | 
. . . . . . 7
⊢
(1r‘𝐹) = (1r‘𝐹) | 
| 22 | 9, 20, 21, 10, 5, 8 | ringnegl 13607 | 
. . . . . 6
⊢ (𝜑 →
(((invg‘𝐹)‘(1r‘𝐹))(.r‘𝐹)𝐵) = ((invg‘𝐹)‘𝐵)) | 
| 23 | 22 | oveq1d 5937 | 
. . . . 5
⊢ (𝜑 →
((((invg‘𝐹)‘(1r‘𝐹))(.r‘𝐹)𝐵) · 𝑋) = (((invg‘𝐹)‘𝐵) · 𝑋)) | 
| 24 | 9, 21 | ringidcl 13576 | 
. . . . . . . 8
⊢ (𝐹 ∈ Ring →
(1r‘𝐹)
∈ 𝐾) | 
| 25 | 5, 24 | syl 14 | 
. . . . . . 7
⊢ (𝜑 → (1r‘𝐹) ∈ 𝐾) | 
| 26 | 9, 10 | grpinvcl 13180 | 
. . . . . . 7
⊢ ((𝐹 ∈ Grp ∧
(1r‘𝐹)
∈ 𝐾) →
((invg‘𝐹)‘(1r‘𝐹)) ∈ 𝐾) | 
| 27 | 7, 25, 26 | syl2anc 411 | 
. . . . . 6
⊢ (𝜑 →
((invg‘𝐹)‘(1r‘𝐹)) ∈ 𝐾) | 
| 28 | 14, 3, 16, 9, 20 | lmodvsass 13869 | 
. . . . . 6
⊢ ((𝑊 ∈ LMod ∧
(((invg‘𝐹)‘(1r‘𝐹)) ∈ 𝐾 ∧ 𝐵 ∈ 𝐾 ∧ 𝑋 ∈ 𝑉)) → ((((invg‘𝐹)‘(1r‘𝐹))(.r‘𝐹)𝐵) · 𝑋) = (((invg‘𝐹)‘(1r‘𝐹)) · (𝐵 · 𝑋))) | 
| 29 | 1, 27, 8, 13, 28 | syl13anc 1251 | 
. . . . 5
⊢ (𝜑 →
((((invg‘𝐹)‘(1r‘𝐹))(.r‘𝐹)𝐵) · 𝑋) = (((invg‘𝐹)‘(1r‘𝐹)) · (𝐵 · 𝑋))) | 
| 30 | 23, 29 | eqtr3d 2231 | 
. . . 4
⊢ (𝜑 →
(((invg‘𝐹)‘𝐵) · 𝑋) = (((invg‘𝐹)‘(1r‘𝐹)) · (𝐵 · 𝑋))) | 
| 31 | 30 | oveq2d 5938 | 
. . 3
⊢ (𝜑 → ((𝐴 · 𝑋)(+g‘𝑊)(((invg‘𝐹)‘𝐵) · 𝑋)) = ((𝐴 · 𝑋)(+g‘𝑊)(((invg‘𝐹)‘(1r‘𝐹)) · (𝐵 · 𝑋)))) | 
| 32 | 19, 31 | eqtrd 2229 | 
. 2
⊢ (𝜑 → ((𝐴(+g‘𝐹)((invg‘𝐹)‘𝐵)) · 𝑋) = ((𝐴 · 𝑋)(+g‘𝑊)(((invg‘𝐹)‘(1r‘𝐹)) · (𝐵 · 𝑋)))) | 
| 33 |   | lmodsubdir.s | 
. . . . 5
⊢ 𝑆 = (-g‘𝐹) | 
| 34 | 9, 17, 10, 33 | grpsubval 13178 | 
. . . 4
⊢ ((𝐴 ∈ 𝐾 ∧ 𝐵 ∈ 𝐾) → (𝐴𝑆𝐵) = (𝐴(+g‘𝐹)((invg‘𝐹)‘𝐵))) | 
| 35 | 2, 8, 34 | syl2anc 411 | 
. . 3
⊢ (𝜑 → (𝐴𝑆𝐵) = (𝐴(+g‘𝐹)((invg‘𝐹)‘𝐵))) | 
| 36 | 35 | oveq1d 5937 | 
. 2
⊢ (𝜑 → ((𝐴𝑆𝐵) · 𝑋) = ((𝐴(+g‘𝐹)((invg‘𝐹)‘𝐵)) · 𝑋)) | 
| 37 | 14, 3, 16, 9 | lmodvscl 13861 | 
. . . 4
⊢ ((𝑊 ∈ LMod ∧ 𝐴 ∈ 𝐾 ∧ 𝑋 ∈ 𝑉) → (𝐴 · 𝑋) ∈ 𝑉) | 
| 38 | 1, 2, 13, 37 | syl3anc 1249 | 
. . 3
⊢ (𝜑 → (𝐴 · 𝑋) ∈ 𝑉) | 
| 39 | 14, 3, 16, 9 | lmodvscl 13861 | 
. . . 4
⊢ ((𝑊 ∈ LMod ∧ 𝐵 ∈ 𝐾 ∧ 𝑋 ∈ 𝑉) → (𝐵 · 𝑋) ∈ 𝑉) | 
| 40 | 1, 8, 13, 39 | syl3anc 1249 | 
. . 3
⊢ (𝜑 → (𝐵 · 𝑋) ∈ 𝑉) | 
| 41 |   | lmodsubdir.m | 
. . . 4
⊢  − =
(-g‘𝑊) | 
| 42 | 14, 15, 41, 3, 16, 10, 21 | lmodvsubval2 13898 | 
. . 3
⊢ ((𝑊 ∈ LMod ∧ (𝐴 · 𝑋) ∈ 𝑉 ∧ (𝐵 · 𝑋) ∈ 𝑉) → ((𝐴 · 𝑋) − (𝐵 · 𝑋)) = ((𝐴 · 𝑋)(+g‘𝑊)(((invg‘𝐹)‘(1r‘𝐹)) · (𝐵 · 𝑋)))) | 
| 43 | 1, 38, 40, 42 | syl3anc 1249 | 
. 2
⊢ (𝜑 → ((𝐴 · 𝑋) − (𝐵 · 𝑋)) = ((𝐴 · 𝑋)(+g‘𝑊)(((invg‘𝐹)‘(1r‘𝐹)) · (𝐵 · 𝑋)))) | 
| 44 | 32, 36, 43 | 3eqtr4d 2239 | 
1
⊢ (𝜑 → ((𝐴𝑆𝐵) · 𝑋) = ((𝐴 · 𝑋) − (𝐵 · 𝑋))) |