Metamath Proof Explorer


Theorem matgsum

Description: Finite commutative sums in a matrix algebra are taken componentwise. (Contributed by AV, 26-Sep-2019)

Ref Expression
Hypotheses matgsum.a A = N Mat R
matgsum.b B = Base A
matgsum.z 0 ˙ = 0 A
matgsum.i φ N Fin
matgsum.j φ J W
matgsum.r φ R Ring
matgsum.f φ y J i N , j N U B
matgsum.w φ finSupp 0 ˙ y J i N , j N U
Assertion matgsum φ A y J i N , j N U = i N , j N R y J U

Proof

Step Hyp Ref Expression
1 matgsum.a A = N Mat R
2 matgsum.b B = Base A
3 matgsum.z 0 ˙ = 0 A
4 matgsum.i φ N Fin
5 matgsum.j φ J W
6 matgsum.r φ R Ring
7 matgsum.f φ y J i N , j N U B
8 matgsum.w φ finSupp 0 ˙ y J i N , j N U
9 5 mptexd φ y J i N , j N U V
10 1 ovexi A V
11 10 a1i φ A V
12 ovexd φ R freeLMod N × N V
13 eqid R freeLMod N × N = R freeLMod N × N
14 1 13 matbas N Fin R Ring Base R freeLMod N × N = Base A
15 4 6 14 syl2anc φ Base R freeLMod N × N = Base A
16 15 eqcomd φ Base A = Base R freeLMod N × N
17 1 13 matplusg N Fin R Ring + R freeLMod N × N = + A
18 4 6 17 syl2anc φ + R freeLMod N × N = + A
19 18 eqcomd φ + A = + R freeLMod N × N
20 9 11 12 16 19 gsumpropd φ A y J i N , j N U = R freeLMod N × N y J i N , j N U
21 mpompts i N , j N U = z N × N 1 st z / i 2 nd z / j U
22 21 a1i φ i N , j N U = z N × N 1 st z / i 2 nd z / j U
23 22 mpteq2dv φ y J i N , j N U = y J z N × N 1 st z / i 2 nd z / j U
24 23 oveq2d φ R freeLMod N × N y J i N , j N U = R freeLMod N × N y J z N × N 1 st z / i 2 nd z / j U
25 eqid Base R freeLMod N × N = Base R freeLMod N × N
26 eqid 0 R freeLMod N × N = 0 R freeLMod N × N
27 xpfi N Fin N Fin N × N Fin
28 4 4 27 syl2anc φ N × N Fin
29 7 2 eleqtrdi φ y J i N , j N U Base A
30 21 eqcomi z N × N 1 st z / i 2 nd z / j U = i N , j N U
31 30 a1i φ y J z N × N 1 st z / i 2 nd z / j U = i N , j N U
32 4 6 jca φ N Fin R Ring
33 32 adantr φ y J N Fin R Ring
34 33 14 syl φ y J Base R freeLMod N × N = Base A
35 29 31 34 3eltr4d φ y J z N × N 1 st z / i 2 nd z / j U Base R freeLMod N × N
36 30 mpteq2i y J z N × N 1 st z / i 2 nd z / j U = y J i N , j N U
37 3 eqcomi 0 A = 0 ˙
38 8 36 37 3brtr4g φ finSupp 0 A y J z N × N 1 st z / i 2 nd z / j U
39 1 13 mat0 N Fin R Ring 0 R freeLMod N × N = 0 A
40 4 6 39 syl2anc φ 0 R freeLMod N × N = 0 A
41 38 40 breqtrrd φ finSupp 0 R freeLMod N × N y J z N × N 1 st z / i 2 nd z / j U
42 13 25 26 28 5 6 35 41 frlmgsum φ R freeLMod N × N y J z N × N 1 st z / i 2 nd z / j U = z N × N R y J 1 st z / i 2 nd z / j U
43 24 42 eqtrd φ R freeLMod N × N y J i N , j N U = z N × N R y J 1 st z / i 2 nd z / j U
44 fvex 2 nd z V
45 csbov2g 2 nd z V 2 nd z / j R y J U = R 2 nd z / j y J U
46 44 45 ax-mp 2 nd z / j R y J U = R 2 nd z / j y J U
47 46 csbeq2i 1 st z / i 2 nd z / j R y J U = 1 st z / i R 2 nd z / j y J U
48 fvex 1 st z V
49 csbov2g 1 st z V 1 st z / i R 2 nd z / j y J U = R 1 st z / i 2 nd z / j y J U
50 48 49 ax-mp 1 st z / i R 2 nd z / j y J U = R 1 st z / i 2 nd z / j y J U
51 csbmpt2 2 nd z V 2 nd z / j y J U = y J 2 nd z / j U
52 44 51 ax-mp 2 nd z / j y J U = y J 2 nd z / j U
53 52 csbeq2i 1 st z / i 2 nd z / j y J U = 1 st z / i y J 2 nd z / j U
54 csbmpt2 1 st z V 1 st z / i y J 2 nd z / j U = y J 1 st z / i 2 nd z / j U
55 48 54 ax-mp 1 st z / i y J 2 nd z / j U = y J 1 st z / i 2 nd z / j U
56 53 55 eqtri 1 st z / i 2 nd z / j y J U = y J 1 st z / i 2 nd z / j U
57 56 oveq2i R 1 st z / i 2 nd z / j y J U = R y J 1 st z / i 2 nd z / j U
58 47 50 57 3eqtrri R y J 1 st z / i 2 nd z / j U = 1 st z / i 2 nd z / j R y J U
59 58 mpteq2i z N × N R y J 1 st z / i 2 nd z / j U = z N × N 1 st z / i 2 nd z / j R y J U
60 mpompts i N , j N R y J U = z N × N 1 st z / i 2 nd z / j R y J U
61 59 60 eqtr4i z N × N R y J 1 st z / i 2 nd z / j U = i N , j N R y J U
62 61 a1i φ z N × N R y J 1 st z / i 2 nd z / j U = i N , j N R y J U
63 20 43 62 3eqtrd φ A y J i N , j N U = i N , j N R y J U