Proof of Theorem lcfrlem23
Step | Hyp | Ref
| Expression |
1 | | lcfrlem22.b |
. . . . . . 7
⊢ 𝐵 = ((𝑁‘{𝑋, 𝑌}) ∩ ( ⊥ ‘{(𝑋 + 𝑌)})) |
2 | 1 | fveq2i 6777 |
. . . . . 6
⊢ ( ⊥
‘𝐵) = ( ⊥
‘((𝑁‘{𝑋, 𝑌}) ∩ ( ⊥ ‘{(𝑋 + 𝑌)}))) |
3 | | lcfrlem17.h |
. . . . . . . 8
⊢ 𝐻 = (LHyp‘𝐾) |
4 | | eqid 2738 |
. . . . . . . 8
⊢
((DIsoH‘𝐾)‘𝑊) = ((DIsoH‘𝐾)‘𝑊) |
5 | | lcfrlem17.u |
. . . . . . . 8
⊢ 𝑈 = ((DVecH‘𝐾)‘𝑊) |
6 | | lcfrlem17.v |
. . . . . . . 8
⊢ 𝑉 = (Base‘𝑈) |
7 | | lcfrlem17.o |
. . . . . . . 8
⊢ ⊥ =
((ocH‘𝐾)‘𝑊) |
8 | | eqid 2738 |
. . . . . . . 8
⊢
((joinH‘𝐾)‘𝑊) = ((joinH‘𝐾)‘𝑊) |
9 | | lcfrlem17.k |
. . . . . . . 8
⊢ (𝜑 → (𝐾 ∈ HL ∧ 𝑊 ∈ 𝐻)) |
10 | | lcfrlem17.n |
. . . . . . . . 9
⊢ 𝑁 = (LSpan‘𝑈) |
11 | | lcfrlem17.x |
. . . . . . . . . 10
⊢ (𝜑 → 𝑋 ∈ (𝑉 ∖ { 0 })) |
12 | 11 | eldifad 3899 |
. . . . . . . . 9
⊢ (𝜑 → 𝑋 ∈ 𝑉) |
13 | | lcfrlem17.y |
. . . . . . . . . 10
⊢ (𝜑 → 𝑌 ∈ (𝑉 ∖ { 0 })) |
14 | 13 | eldifad 3899 |
. . . . . . . . 9
⊢ (𝜑 → 𝑌 ∈ 𝑉) |
15 | 3, 5, 6, 10, 4, 9,
12, 14 | dihprrn 39440 |
. . . . . . . 8
⊢ (𝜑 → (𝑁‘{𝑋, 𝑌}) ∈ ran ((DIsoH‘𝐾)‘𝑊)) |
16 | 3, 5, 9 | dvhlmod 39124 |
. . . . . . . . . . 11
⊢ (𝜑 → 𝑈 ∈ LMod) |
17 | | lcfrlem17.p |
. . . . . . . . . . . 12
⊢ + =
(+g‘𝑈) |
18 | 6, 17 | lmodvacl 20137 |
. . . . . . . . . . 11
⊢ ((𝑈 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → (𝑋 + 𝑌) ∈ 𝑉) |
19 | 16, 12, 14, 18 | syl3anc 1370 |
. . . . . . . . . 10
⊢ (𝜑 → (𝑋 + 𝑌) ∈ 𝑉) |
20 | 19 | snssd 4742 |
. . . . . . . . 9
⊢ (𝜑 → {(𝑋 + 𝑌)} ⊆ 𝑉) |
21 | 3, 4, 5, 6, 7 | dochcl 39367 |
. . . . . . . . 9
⊢ (((𝐾 ∈ HL ∧ 𝑊 ∈ 𝐻) ∧ {(𝑋 + 𝑌)} ⊆ 𝑉) → ( ⊥ ‘{(𝑋 + 𝑌)}) ∈ ran ((DIsoH‘𝐾)‘𝑊)) |
22 | 9, 20, 21 | syl2anc 584 |
. . . . . . . 8
⊢ (𝜑 → ( ⊥ ‘{(𝑋 + 𝑌)}) ∈ ran ((DIsoH‘𝐾)‘𝑊)) |
23 | 3, 4, 5, 6, 7, 8, 9, 15, 22 | dochdmm1 39424 |
. . . . . . 7
⊢ (𝜑 → ( ⊥ ‘((𝑁‘{𝑋, 𝑌}) ∩ ( ⊥ ‘{(𝑋 + 𝑌)}))) = (( ⊥ ‘(𝑁‘{𝑋, 𝑌}))((joinH‘𝐾)‘𝑊)( ⊥ ‘( ⊥
‘{(𝑋 + 𝑌)})))) |
24 | 3, 5, 7, 6, 10, 9,
19 | dochocsn 39395 |
. . . . . . . 8
⊢ (𝜑 → ( ⊥ ‘( ⊥
‘{(𝑋 + 𝑌)})) = (𝑁‘{(𝑋 + 𝑌)})) |
25 | 24 | oveq2d 7291 |
. . . . . . 7
⊢ (𝜑 → (( ⊥ ‘(𝑁‘{𝑋, 𝑌}))((joinH‘𝐾)‘𝑊)( ⊥ ‘( ⊥
‘{(𝑋 + 𝑌)}))) = (( ⊥ ‘(𝑁‘{𝑋, 𝑌}))((joinH‘𝐾)‘𝑊)(𝑁‘{(𝑋 + 𝑌)}))) |
26 | | lcfrlem23.s |
. . . . . . . 8
⊢ ⊕ =
(LSSum‘𝑈) |
27 | | prssi 4754 |
. . . . . . . . . . 11
⊢ ((𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → {𝑋, 𝑌} ⊆ 𝑉) |
28 | 12, 14, 27 | syl2anc 584 |
. . . . . . . . . 10
⊢ (𝜑 → {𝑋, 𝑌} ⊆ 𝑉) |
29 | 6, 10 | lspssv 20245 |
. . . . . . . . . 10
⊢ ((𝑈 ∈ LMod ∧ {𝑋, 𝑌} ⊆ 𝑉) → (𝑁‘{𝑋, 𝑌}) ⊆ 𝑉) |
30 | 16, 28, 29 | syl2anc 584 |
. . . . . . . . 9
⊢ (𝜑 → (𝑁‘{𝑋, 𝑌}) ⊆ 𝑉) |
31 | 3, 4, 5, 6, 7 | dochcl 39367 |
. . . . . . . . 9
⊢ (((𝐾 ∈ HL ∧ 𝑊 ∈ 𝐻) ∧ (𝑁‘{𝑋, 𝑌}) ⊆ 𝑉) → ( ⊥ ‘(𝑁‘{𝑋, 𝑌})) ∈ ran ((DIsoH‘𝐾)‘𝑊)) |
32 | 9, 30, 31 | syl2anc 584 |
. . . . . . . 8
⊢ (𝜑 → ( ⊥ ‘(𝑁‘{𝑋, 𝑌})) ∈ ran ((DIsoH‘𝐾)‘𝑊)) |
33 | 3, 5, 6, 26, 10, 4, 8, 9, 32,
19 | dihjat1 39443 |
. . . . . . 7
⊢ (𝜑 → (( ⊥ ‘(𝑁‘{𝑋, 𝑌}))((joinH‘𝐾)‘𝑊)(𝑁‘{(𝑋 + 𝑌)})) = (( ⊥ ‘(𝑁‘{𝑋, 𝑌})) ⊕ (𝑁‘{(𝑋 + 𝑌)}))) |
34 | 23, 25, 33 | 3eqtrd 2782 |
. . . . . 6
⊢ (𝜑 → ( ⊥ ‘((𝑁‘{𝑋, 𝑌}) ∩ ( ⊥ ‘{(𝑋 + 𝑌)}))) = (( ⊥ ‘(𝑁‘{𝑋, 𝑌})) ⊕ (𝑁‘{(𝑋 + 𝑌)}))) |
35 | 2, 34 | eqtrid 2790 |
. . . . 5
⊢ (𝜑 → ( ⊥ ‘𝐵) = (( ⊥ ‘(𝑁‘{𝑋, 𝑌})) ⊕ (𝑁‘{(𝑋 + 𝑌)}))) |
36 | 35 | ineq2d 4146 |
. . . 4
⊢ (𝜑 → (((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∩ ( ⊥ ‘𝐵)) = (((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∩ (( ⊥ ‘(𝑁‘{𝑋, 𝑌})) ⊕ (𝑁‘{(𝑋 + 𝑌)})))) |
37 | | eqid 2738 |
. . . . . . . 8
⊢
(LSubSp‘𝑈) =
(LSubSp‘𝑈) |
38 | 37 | lsssssubg 20220 |
. . . . . . 7
⊢ (𝑈 ∈ LMod →
(LSubSp‘𝑈) ⊆
(SubGrp‘𝑈)) |
39 | 16, 38 | syl 17 |
. . . . . 6
⊢ (𝜑 → (LSubSp‘𝑈) ⊆ (SubGrp‘𝑈)) |
40 | 6, 37, 10 | lspsncl 20239 |
. . . . . . . 8
⊢ ((𝑈 ∈ LMod ∧ 𝑋 ∈ 𝑉) → (𝑁‘{𝑋}) ∈ (LSubSp‘𝑈)) |
41 | 16, 12, 40 | syl2anc 584 |
. . . . . . 7
⊢ (𝜑 → (𝑁‘{𝑋}) ∈ (LSubSp‘𝑈)) |
42 | 6, 37, 10 | lspsncl 20239 |
. . . . . . . 8
⊢ ((𝑈 ∈ LMod ∧ 𝑌 ∈ 𝑉) → (𝑁‘{𝑌}) ∈ (LSubSp‘𝑈)) |
43 | 16, 14, 42 | syl2anc 584 |
. . . . . . 7
⊢ (𝜑 → (𝑁‘{𝑌}) ∈ (LSubSp‘𝑈)) |
44 | 37, 26 | lsmcl 20345 |
. . . . . . 7
⊢ ((𝑈 ∈ LMod ∧ (𝑁‘{𝑋}) ∈ (LSubSp‘𝑈) ∧ (𝑁‘{𝑌}) ∈ (LSubSp‘𝑈)) → ((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∈ (LSubSp‘𝑈)) |
45 | 16, 41, 43, 44 | syl3anc 1370 |
. . . . . 6
⊢ (𝜑 → ((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∈ (LSubSp‘𝑈)) |
46 | 39, 45 | sseldd 3922 |
. . . . 5
⊢ (𝜑 → ((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∈ (SubGrp‘𝑈)) |
47 | 3, 5, 6, 37, 7 | dochlss 39368 |
. . . . . . 7
⊢ (((𝐾 ∈ HL ∧ 𝑊 ∈ 𝐻) ∧ (𝑁‘{𝑋, 𝑌}) ⊆ 𝑉) → ( ⊥ ‘(𝑁‘{𝑋, 𝑌})) ∈ (LSubSp‘𝑈)) |
48 | 9, 30, 47 | syl2anc 584 |
. . . . . 6
⊢ (𝜑 → ( ⊥ ‘(𝑁‘{𝑋, 𝑌})) ∈ (LSubSp‘𝑈)) |
49 | 39, 48 | sseldd 3922 |
. . . . 5
⊢ (𝜑 → ( ⊥ ‘(𝑁‘{𝑋, 𝑌})) ∈ (SubGrp‘𝑈)) |
50 | 6, 37, 10 | lspsncl 20239 |
. . . . . . 7
⊢ ((𝑈 ∈ LMod ∧ (𝑋 + 𝑌) ∈ 𝑉) → (𝑁‘{(𝑋 + 𝑌)}) ∈ (LSubSp‘𝑈)) |
51 | 16, 19, 50 | syl2anc 584 |
. . . . . 6
⊢ (𝜑 → (𝑁‘{(𝑋 + 𝑌)}) ∈ (LSubSp‘𝑈)) |
52 | 39, 51 | sseldd 3922 |
. . . . 5
⊢ (𝜑 → (𝑁‘{(𝑋 + 𝑌)}) ∈ (SubGrp‘𝑈)) |
53 | 6, 17, 10, 26 | lspsntri 20359 |
. . . . . 6
⊢ ((𝑈 ∈ LMod ∧ 𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉) → (𝑁‘{(𝑋 + 𝑌)}) ⊆ ((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌}))) |
54 | 16, 12, 14, 53 | syl3anc 1370 |
. . . . 5
⊢ (𝜑 → (𝑁‘{(𝑋 + 𝑌)}) ⊆ ((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌}))) |
55 | 26 | lsmmod2 19282 |
. . . . 5
⊢
(((((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∈ (SubGrp‘𝑈) ∧ ( ⊥ ‘(𝑁‘{𝑋, 𝑌})) ∈ (SubGrp‘𝑈) ∧ (𝑁‘{(𝑋 + 𝑌)}) ∈ (SubGrp‘𝑈)) ∧ (𝑁‘{(𝑋 + 𝑌)}) ⊆ ((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌}))) → (((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∩ (( ⊥ ‘(𝑁‘{𝑋, 𝑌})) ⊕ (𝑁‘{(𝑋 + 𝑌)}))) = ((((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∩ ( ⊥ ‘(𝑁‘{𝑋, 𝑌}))) ⊕ (𝑁‘{(𝑋 + 𝑌)}))) |
56 | 46, 49, 52, 54, 55 | syl31anc 1372 |
. . . 4
⊢ (𝜑 → (((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∩ (( ⊥ ‘(𝑁‘{𝑋, 𝑌})) ⊕ (𝑁‘{(𝑋 + 𝑌)}))) = ((((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∩ ( ⊥ ‘(𝑁‘{𝑋, 𝑌}))) ⊕ (𝑁‘{(𝑋 + 𝑌)}))) |
57 | 6, 10, 26, 16, 12, 14 | lsmpr 20351 |
. . . . . . . 8
⊢ (𝜑 → (𝑁‘{𝑋, 𝑌}) = ((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌}))) |
58 | 57 | ineq1d 4145 |
. . . . . . 7
⊢ (𝜑 → ((𝑁‘{𝑋, 𝑌}) ∩ ( ⊥ ‘(𝑁‘{𝑋, 𝑌}))) = (((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∩ ( ⊥ ‘(𝑁‘{𝑋, 𝑌})))) |
59 | 6, 37, 10, 16, 12, 14 | lspprcl 20240 |
. . . . . . . 8
⊢ (𝜑 → (𝑁‘{𝑋, 𝑌}) ∈ (LSubSp‘𝑈)) |
60 | | lcfrlem17.z |
. . . . . . . . 9
⊢ 0 =
(0g‘𝑈) |
61 | 3, 5, 37, 60, 7 | dochnoncon 39405 |
. . . . . . . 8
⊢ (((𝐾 ∈ HL ∧ 𝑊 ∈ 𝐻) ∧ (𝑁‘{𝑋, 𝑌}) ∈ (LSubSp‘𝑈)) → ((𝑁‘{𝑋, 𝑌}) ∩ ( ⊥ ‘(𝑁‘{𝑋, 𝑌}))) = { 0 }) |
62 | 9, 59, 61 | syl2anc 584 |
. . . . . . 7
⊢ (𝜑 → ((𝑁‘{𝑋, 𝑌}) ∩ ( ⊥ ‘(𝑁‘{𝑋, 𝑌}))) = { 0 }) |
63 | 58, 62 | eqtr3d 2780 |
. . . . . 6
⊢ (𝜑 → (((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∩ ( ⊥ ‘(𝑁‘{𝑋, 𝑌}))) = { 0 }) |
64 | 63 | oveq1d 7290 |
. . . . 5
⊢ (𝜑 → ((((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∩ ( ⊥ ‘(𝑁‘{𝑋, 𝑌}))) ⊕ (𝑁‘{(𝑋 + 𝑌)})) = ({ 0 } ⊕ (𝑁‘{(𝑋 + 𝑌)}))) |
65 | 60, 26 | lsm02 19278 |
. . . . . 6
⊢ ((𝑁‘{(𝑋 + 𝑌)}) ∈ (SubGrp‘𝑈) → ({ 0 } ⊕ (𝑁‘{(𝑋 + 𝑌)})) = (𝑁‘{(𝑋 + 𝑌)})) |
66 | 52, 65 | syl 17 |
. . . . 5
⊢ (𝜑 → ({ 0 } ⊕ (𝑁‘{(𝑋 + 𝑌)})) = (𝑁‘{(𝑋 + 𝑌)})) |
67 | 64, 66 | eqtrd 2778 |
. . . 4
⊢ (𝜑 → ((((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∩ ( ⊥ ‘(𝑁‘{𝑋, 𝑌}))) ⊕ (𝑁‘{(𝑋 + 𝑌)})) = (𝑁‘{(𝑋 + 𝑌)})) |
68 | 36, 56, 67 | 3eqtrd 2782 |
. . 3
⊢ (𝜑 → (((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∩ ( ⊥ ‘𝐵)) = (𝑁‘{(𝑋 + 𝑌)})) |
69 | 68 | fveq2d 6778 |
. 2
⊢ (𝜑 → ( ⊥ ‘(((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∩ ( ⊥ ‘𝐵))) = ( ⊥ ‘(𝑁‘{(𝑋 + 𝑌)}))) |
70 | 3, 5, 6, 26, 10, 4, 9, 12, 14 | dihsmsnrn 39449 |
. . . 4
⊢ (𝜑 → ((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∈ ran ((DIsoH‘𝐾)‘𝑊)) |
71 | | lcfrlem17.a |
. . . . . 6
⊢ 𝐴 = (LSAtoms‘𝑈) |
72 | | lcfrlem17.ne |
. . . . . . 7
⊢ (𝜑 → (𝑁‘{𝑋}) ≠ (𝑁‘{𝑌})) |
73 | 3, 7, 5, 6, 17, 60, 10, 71, 9, 11, 13, 72, 1 | lcfrlem22 39578 |
. . . . . 6
⊢ (𝜑 → 𝐵 ∈ 𝐴) |
74 | 6, 71, 16, 73 | lsatssv 37012 |
. . . . 5
⊢ (𝜑 → 𝐵 ⊆ 𝑉) |
75 | 3, 4, 5, 6, 7 | dochcl 39367 |
. . . . 5
⊢ (((𝐾 ∈ HL ∧ 𝑊 ∈ 𝐻) ∧ 𝐵 ⊆ 𝑉) → ( ⊥ ‘𝐵) ∈ ran ((DIsoH‘𝐾)‘𝑊)) |
76 | 9, 74, 75 | syl2anc 584 |
. . . 4
⊢ (𝜑 → ( ⊥ ‘𝐵) ∈ ran ((DIsoH‘𝐾)‘𝑊)) |
77 | 3, 4, 5, 6, 7, 8, 9, 70, 76 | dochdmm1 39424 |
. . 3
⊢ (𝜑 → ( ⊥ ‘(((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∩ ( ⊥ ‘𝐵))) = (( ⊥ ‘((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})))((joinH‘𝐾)‘𝑊)( ⊥ ‘( ⊥
‘𝐵)))) |
78 | 57 | fveq2d 6778 |
. . . . 5
⊢ (𝜑 → ( ⊥ ‘(𝑁‘{𝑋, 𝑌})) = ( ⊥ ‘((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})))) |
79 | 3, 5, 7, 6, 10, 9,
28 | dochocsp 39393 |
. . . . 5
⊢ (𝜑 → ( ⊥ ‘(𝑁‘{𝑋, 𝑌})) = ( ⊥ ‘{𝑋, 𝑌})) |
80 | 78, 79 | eqtr3d 2780 |
. . . 4
⊢ (𝜑 → ( ⊥ ‘((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌}))) = ( ⊥ ‘{𝑋, 𝑌})) |
81 | 3, 5, 4, 71 | dih1dimat 39344 |
. . . . . 6
⊢ (((𝐾 ∈ HL ∧ 𝑊 ∈ 𝐻) ∧ 𝐵 ∈ 𝐴) → 𝐵 ∈ ran ((DIsoH‘𝐾)‘𝑊)) |
82 | 9, 73, 81 | syl2anc 584 |
. . . . 5
⊢ (𝜑 → 𝐵 ∈ ran ((DIsoH‘𝐾)‘𝑊)) |
83 | 3, 4, 7 | dochoc 39381 |
. . . . 5
⊢ (((𝐾 ∈ HL ∧ 𝑊 ∈ 𝐻) ∧ 𝐵 ∈ ran ((DIsoH‘𝐾)‘𝑊)) → ( ⊥ ‘( ⊥
‘𝐵)) = 𝐵) |
84 | 9, 82, 83 | syl2anc 584 |
. . . 4
⊢ (𝜑 → ( ⊥ ‘( ⊥
‘𝐵)) = 𝐵) |
85 | 80, 84 | oveq12d 7293 |
. . 3
⊢ (𝜑 → (( ⊥ ‘((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})))((joinH‘𝐾)‘𝑊)( ⊥ ‘( ⊥
‘𝐵))) = (( ⊥
‘{𝑋, 𝑌})((joinH‘𝐾)‘𝑊)𝐵)) |
86 | 3, 4, 5, 6, 7 | dochcl 39367 |
. . . . 5
⊢ (((𝐾 ∈ HL ∧ 𝑊 ∈ 𝐻) ∧ {𝑋, 𝑌} ⊆ 𝑉) → ( ⊥ ‘{𝑋, 𝑌}) ∈ ran ((DIsoH‘𝐾)‘𝑊)) |
87 | 9, 28, 86 | syl2anc 584 |
. . . 4
⊢ (𝜑 → ( ⊥ ‘{𝑋, 𝑌}) ∈ ran ((DIsoH‘𝐾)‘𝑊)) |
88 | 3, 4, 8, 5, 26, 71, 9, 87, 73 | dihjat2 39445 |
. . 3
⊢ (𝜑 → (( ⊥ ‘{𝑋, 𝑌})((joinH‘𝐾)‘𝑊)𝐵) = (( ⊥ ‘{𝑋, 𝑌}) ⊕ 𝐵)) |
89 | 77, 85, 88 | 3eqtrd 2782 |
. 2
⊢ (𝜑 → ( ⊥ ‘(((𝑁‘{𝑋}) ⊕ (𝑁‘{𝑌})) ∩ ( ⊥ ‘𝐵))) = (( ⊥ ‘{𝑋, 𝑌}) ⊕ 𝐵)) |
90 | 3, 5, 7, 6, 10, 9,
20 | dochocsp 39393 |
. 2
⊢ (𝜑 → ( ⊥ ‘(𝑁‘{(𝑋 + 𝑌)})) = ( ⊥ ‘{(𝑋 + 𝑌)})) |
91 | 69, 89, 90 | 3eqtr3d 2786 |
1
⊢ (𝜑 → (( ⊥ ‘{𝑋, 𝑌}) ⊕ 𝐵) = ( ⊥ ‘{(𝑋 + 𝑌)})) |