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