Proof of Theorem lmodcom
Step | Hyp | Ref
| Expression |
1 | | simp1 1135 |
. . . . . . . 8
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → 𝑊 ∈ LMod) |
2 | | eqid 2738 |
. . . . . . . . . . 11
⊢
(Scalar‘𝑊) =
(Scalar‘𝑊) |
3 | | eqid 2738 |
. . . . . . . . . . 11
⊢
(Base‘(Scalar‘𝑊)) = (Base‘(Scalar‘𝑊)) |
4 | | eqid 2738 |
. . . . . . . . . . 11
⊢
(1r‘(Scalar‘𝑊)) =
(1r‘(Scalar‘𝑊)) |
5 | 2, 3, 4 | lmod1cl 20150 |
. . . . . . . . . 10
⊢ (𝑊 ∈ LMod →
(1r‘(Scalar‘𝑊)) ∈ (Base‘(Scalar‘𝑊))) |
6 | 1, 5 | syl 17 |
. . . . . . . . 9
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) →
(1r‘(Scalar‘𝑊)) ∈ (Base‘(Scalar‘𝑊))) |
7 | | eqid 2738 |
. . . . . . . . . 10
⊢
(+g‘(Scalar‘𝑊)) =
(+g‘(Scalar‘𝑊)) |
8 | 2, 3, 7 | lmodacl 20134 |
. . . . . . . . 9
⊢ ((𝑊 ∈ LMod ∧
(1r‘(Scalar‘𝑊)) ∈ (Base‘(Scalar‘𝑊)) ∧
(1r‘(Scalar‘𝑊)) ∈ (Base‘(Scalar‘𝑊))) →
((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊))) ∈
(Base‘(Scalar‘𝑊))) |
9 | 1, 6, 6, 8 | syl3anc 1370 |
. . . . . . . 8
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) →
((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊))) ∈
(Base‘(Scalar‘𝑊))) |
10 | | simp2 1136 |
. . . . . . . 8
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → 𝑋 ∈ 𝑉) |
11 | | simp3 1137 |
. . . . . . . 8
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → 𝑌 ∈ 𝑉) |
12 | | lmodcom.v |
. . . . . . . . 9
⊢ 𝑉 = (Base‘𝑊) |
13 | | lmodcom.a |
. . . . . . . . 9
⊢ + =
(+g‘𝑊) |
14 | | eqid 2738 |
. . . . . . . . 9
⊢ (
·𝑠 ‘𝑊) = ( ·𝑠
‘𝑊) |
15 | 12, 13, 2, 14, 3 | lmodvsdi 20146 |
. . . . . . . 8
⊢ ((𝑊 ∈ LMod ∧
(((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊))) ∈
(Base‘(Scalar‘𝑊)) ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)) →
(((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)(𝑋 + 𝑌)) =
((((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)𝑋) +
(((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)𝑌))) |
16 | 1, 9, 10, 11, 15 | syl13anc 1371 |
. . . . . . 7
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) →
(((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)(𝑋 + 𝑌)) =
((((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)𝑋) +
(((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)𝑌))) |
17 | 12, 13 | lmodvacl 20137 |
. . . . . . . 8
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → (𝑋 + 𝑌) ∈ 𝑉) |
18 | 12, 13, 2, 14, 3, 7 | lmodvsdir 20147 |
. . . . . . . 8
⊢ ((𝑊 ∈ LMod ∧
((1r‘(Scalar‘𝑊)) ∈ (Base‘(Scalar‘𝑊)) ∧
(1r‘(Scalar‘𝑊)) ∈ (Base‘(Scalar‘𝑊)) ∧ (𝑋 + 𝑌) ∈ 𝑉)) →
(((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)(𝑋 + 𝑌)) =
(((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)(𝑋 + 𝑌)) +
((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)(𝑋 + 𝑌)))) |
19 | 1, 6, 6, 17, 18 | syl13anc 1371 |
. . . . . . 7
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) →
(((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)(𝑋 + 𝑌)) =
(((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)(𝑋 + 𝑌)) +
((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)(𝑋 + 𝑌)))) |
20 | 16, 19 | eqtr3d 2780 |
. . . . . 6
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) →
((((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)𝑋) +
(((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)𝑌)) =
(((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)(𝑋 + 𝑌)) +
((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)(𝑋 + 𝑌)))) |
21 | 12, 13, 2, 14, 3, 7 | lmodvsdir 20147 |
. . . . . . . . 9
⊢ ((𝑊 ∈ LMod ∧
((1r‘(Scalar‘𝑊)) ∈ (Base‘(Scalar‘𝑊)) ∧
(1r‘(Scalar‘𝑊)) ∈ (Base‘(Scalar‘𝑊)) ∧ 𝑋 ∈ 𝑉)) →
(((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)𝑋) =
(((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)𝑋) +
((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)𝑋))) |
22 | 1, 6, 6, 10, 21 | syl13anc 1371 |
. . . . . . . 8
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) →
(((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)𝑋) =
(((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)𝑋) +
((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)𝑋))) |
23 | 12, 2, 14, 4 | lmodvs1 20151 |
. . . . . . . . . 10
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉) →
((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)𝑋) = 𝑋) |
24 | 1, 10, 23 | syl2anc 584 |
. . . . . . . . 9
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) →
((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)𝑋) = 𝑋) |
25 | 24, 24 | oveq12d 7293 |
. . . . . . . 8
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) →
(((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)𝑋) +
((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)𝑋)) = (𝑋 + 𝑋)) |
26 | 22, 25 | eqtrd 2778 |
. . . . . . 7
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) →
(((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)𝑋) = (𝑋 + 𝑋)) |
27 | 12, 13, 2, 14, 3, 7 | lmodvsdir 20147 |
. . . . . . . . 9
⊢ ((𝑊 ∈ LMod ∧
((1r‘(Scalar‘𝑊)) ∈ (Base‘(Scalar‘𝑊)) ∧
(1r‘(Scalar‘𝑊)) ∈ (Base‘(Scalar‘𝑊)) ∧ 𝑌 ∈ 𝑉)) →
(((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)𝑌) =
(((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)𝑌) +
((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)𝑌))) |
28 | 1, 6, 6, 11, 27 | syl13anc 1371 |
. . . . . . . 8
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) →
(((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)𝑌) =
(((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)𝑌) +
((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)𝑌))) |
29 | 12, 2, 14, 4 | lmodvs1 20151 |
. . . . . . . . . 10
⊢ ((𝑊 ∈ LMod ∧ 𝑌 ∈ 𝑉) →
((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)𝑌) = 𝑌) |
30 | 1, 11, 29 | syl2anc 584 |
. . . . . . . . 9
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) →
((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)𝑌) = 𝑌) |
31 | 30, 30 | oveq12d 7293 |
. . . . . . . 8
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) →
(((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)𝑌) +
((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)𝑌)) = (𝑌 + 𝑌)) |
32 | 28, 31 | eqtrd 2778 |
. . . . . . 7
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) →
(((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)𝑌) = (𝑌 + 𝑌)) |
33 | 26, 32 | oveq12d 7293 |
. . . . . 6
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) →
((((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)𝑋) +
(((1r‘(Scalar‘𝑊))(+g‘(Scalar‘𝑊))(1r‘(Scalar‘𝑊)))(
·𝑠 ‘𝑊)𝑌)) = ((𝑋 + 𝑋) + (𝑌 + 𝑌))) |
34 | 12, 2, 14, 4 | lmodvs1 20151 |
. . . . . . . 8
⊢ ((𝑊 ∈ LMod ∧ (𝑋 + 𝑌) ∈ 𝑉) →
((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)(𝑋 + 𝑌)) = (𝑋 + 𝑌)) |
35 | 1, 17, 34 | syl2anc 584 |
. . . . . . 7
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) →
((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)(𝑋 + 𝑌)) = (𝑋 + 𝑌)) |
36 | 35, 35 | oveq12d 7293 |
. . . . . 6
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) →
(((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)(𝑋 + 𝑌)) +
((1r‘(Scalar‘𝑊))( ·𝑠
‘𝑊)(𝑋 + 𝑌))) = ((𝑋 + 𝑌) + (𝑋 + 𝑌))) |
37 | 20, 33, 36 | 3eqtr3d 2786 |
. . . . 5
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → ((𝑋 + 𝑋) + (𝑌 + 𝑌)) = ((𝑋 + 𝑌) + (𝑋 + 𝑌))) |
38 | 12, 13 | lmodvacl 20137 |
. . . . . . 7
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑋 ∈ 𝑉) → (𝑋 + 𝑋) ∈ 𝑉) |
39 | 1, 10, 10, 38 | syl3anc 1370 |
. . . . . 6
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → (𝑋 + 𝑋) ∈ 𝑉) |
40 | 12, 13 | lmodass 20138 |
. . . . . 6
⊢ ((𝑊 ∈ LMod ∧ ((𝑋 + 𝑋) ∈ 𝑉 ∧ 𝑌 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)) → (((𝑋 + 𝑋) + 𝑌) + 𝑌) = ((𝑋 + 𝑋) + (𝑌 + 𝑌))) |
41 | 1, 39, 11, 11, 40 | syl13anc 1371 |
. . . . 5
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → (((𝑋 + 𝑋) + 𝑌) + 𝑌) = ((𝑋 + 𝑋) + (𝑌 + 𝑌))) |
42 | 12, 13 | lmodass 20138 |
. . . . . 6
⊢ ((𝑊 ∈ LMod ∧ ((𝑋 + 𝑌) ∈ 𝑉 ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)) → (((𝑋 + 𝑌) + 𝑋) + 𝑌) = ((𝑋 + 𝑌) + (𝑋 + 𝑌))) |
43 | 1, 17, 10, 11, 42 | syl13anc 1371 |
. . . . 5
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → (((𝑋 + 𝑌) + 𝑋) + 𝑌) = ((𝑋 + 𝑌) + (𝑋 + 𝑌))) |
44 | 37, 41, 43 | 3eqtr4d 2788 |
. . . 4
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → (((𝑋 + 𝑋) + 𝑌) + 𝑌) = (((𝑋 + 𝑌) + 𝑋) + 𝑌)) |
45 | | lmodgrp 20130 |
. . . . . 6
⊢ (𝑊 ∈ LMod → 𝑊 ∈ Grp) |
46 | 1, 45 | syl 17 |
. . . . 5
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → 𝑊 ∈ Grp) |
47 | 12, 13 | lmodvacl 20137 |
. . . . . 6
⊢ ((𝑊 ∈ LMod ∧ (𝑋 + 𝑋) ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → ((𝑋 + 𝑋) + 𝑌) ∈ 𝑉) |
48 | 1, 39, 11, 47 | syl3anc 1370 |
. . . . 5
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → ((𝑋 + 𝑋) + 𝑌) ∈ 𝑉) |
49 | 12, 13 | lmodvacl 20137 |
. . . . . 6
⊢ ((𝑊 ∈ LMod ∧ (𝑋 + 𝑌) ∈ 𝑉 ∧ 𝑋 ∈ 𝑉) → ((𝑋 + 𝑌) + 𝑋) ∈ 𝑉) |
50 | 1, 17, 10, 49 | syl3anc 1370 |
. . . . 5
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → ((𝑋 + 𝑌) + 𝑋) ∈ 𝑉) |
51 | 12, 13 | grprcan 18613 |
. . . . 5
⊢ ((𝑊 ∈ Grp ∧ (((𝑋 + 𝑋) + 𝑌) ∈ 𝑉 ∧ ((𝑋 + 𝑌) + 𝑋) ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)) → ((((𝑋 + 𝑋) + 𝑌) + 𝑌) = (((𝑋 + 𝑌) + 𝑋) + 𝑌) ↔ ((𝑋 + 𝑋) + 𝑌) = ((𝑋 + 𝑌) + 𝑋))) |
52 | 46, 48, 50, 11, 51 | syl13anc 1371 |
. . . 4
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → ((((𝑋 + 𝑋) + 𝑌) + 𝑌) = (((𝑋 + 𝑌) + 𝑋) + 𝑌) ↔ ((𝑋 + 𝑋) + 𝑌) = ((𝑋 + 𝑌) + 𝑋))) |
53 | 44, 52 | mpbid 231 |
. . 3
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → ((𝑋 + 𝑋) + 𝑌) = ((𝑋 + 𝑌) + 𝑋)) |
54 | 12, 13 | lmodass 20138 |
. . . 4
⊢ ((𝑊 ∈ LMod ∧ (𝑋 ∈ 𝑉 ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)) → ((𝑋 + 𝑋) + 𝑌) = (𝑋 + (𝑋 + 𝑌))) |
55 | 1, 10, 10, 11, 54 | syl13anc 1371 |
. . 3
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → ((𝑋 + 𝑋) + 𝑌) = (𝑋 + (𝑋 + 𝑌))) |
56 | 12, 13 | lmodass 20138 |
. . . 4
⊢ ((𝑊 ∈ LMod ∧ (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉 ∧ 𝑋 ∈ 𝑉)) → ((𝑋 + 𝑌) + 𝑋) = (𝑋 + (𝑌 + 𝑋))) |
57 | 1, 10, 11, 10, 56 | syl13anc 1371 |
. . 3
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → ((𝑋 + 𝑌) + 𝑋) = (𝑋 + (𝑌 + 𝑋))) |
58 | 53, 55, 57 | 3eqtr3d 2786 |
. 2
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → (𝑋 + (𝑋 + 𝑌)) = (𝑋 + (𝑌 + 𝑋))) |
59 | 12, 13 | lmodvacl 20137 |
. . . 4
⊢ ((𝑊 ∈ LMod ∧ 𝑌 ∈ 𝑉 ∧ 𝑋 ∈ 𝑉) → (𝑌 + 𝑋) ∈ 𝑉) |
60 | 59 | 3com23 1125 |
. . 3
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → (𝑌 + 𝑋) ∈ 𝑉) |
61 | 12, 13 | lmodlcan 20139 |
. . 3
⊢ ((𝑊 ∈ LMod ∧ ((𝑋 + 𝑌) ∈ 𝑉 ∧ (𝑌 + 𝑋) ∈ 𝑉 ∧ 𝑋 ∈ 𝑉)) → ((𝑋 + (𝑋 + 𝑌)) = (𝑋 + (𝑌 + 𝑋)) ↔ (𝑋 + 𝑌) = (𝑌 + 𝑋))) |
62 | 1, 17, 60, 10, 61 | syl13anc 1371 |
. 2
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → ((𝑋 + (𝑋 + 𝑌)) = (𝑋 + (𝑌 + 𝑋)) ↔ (𝑋 + 𝑌) = (𝑌 + 𝑋))) |
63 | 58, 62 | mpbid 231 |
1
⊢ ((𝑊 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → (𝑋 + 𝑌) = (𝑌 + 𝑋)) |