Metamath Proof Explorer


Theorem dprdfinv

Description: Take the inverse of a group sum over a family of elements of disjoint subgroups. (Contributed by Mario Carneiro, 25-Apr-2016) (Revised by AV, 14-Jul-2019)

Ref Expression
Hypotheses eldprdi.0 ⊢ 0 ˙ = 0 G
eldprdi.w ⊢ W = h ∈ ⨉ i ∈ I S ⁡ i | finSupp 0 ˙⁡ h
eldprdi.1 ⊢ φ → G dom ⁡ DProd S
eldprdi.2 ⊢ φ → dom ⁡ S = I
eldprdi.3 ⊢ φ → F ∈ W
dprdfinv.b ⊢ N = inv g ⁡ G
Assertion dprdfinv ⊢ φ → N ∘ F ∈ W ∧ ∑ G N ∘ F = N ⁡ ∑ G F

Proof

Step Hyp Ref Expression
1 eldprdi.0 ⊢ 0 ˙ = 0 G
2 eldprdi.w ⊢ W = h ∈ ⨉ i ∈ I S ⁡ i | finSupp 0 ˙⁡ h
3 eldprdi.1 ⊢ φ → G dom ⁡ DProd S
4 eldprdi.2 ⊢ φ → dom ⁡ S = I
5 eldprdi.3 ⊢ φ → F ∈ W
6 dprdfinv.b ⊢ N = inv g ⁡ G
7 dprdgrp ⊢ G dom ⁡ DProd S → G ∈ Grp
8 3 7 syl ⊢ φ → G ∈ Grp
9 eqid ⊢ Base G = Base G
10 9 6 grpinvf ⊢ G ∈ Grp → N : Base G ⟶ Base G
11 8 10 syl ⊢ φ → N : Base G ⟶ Base G
12 2 3 4 5 9 dprdff ⊢ φ → F : I ⟶ Base G
13 fcompt ⊢ N : Base G ⟶ Base G ∧ F : I ⟶ Base G → N ∘ F = x ∈ I ⟼ N ⁡ F ⁡ x
14 11 12 13 syl2anc ⊢ φ → N ∘ F = x ∈ I ⟼ N ⁡ F ⁡ x
15 3 4 dprdf2 ⊢ φ → S : I ⟶ SubGrp ⁡ G
16 15 ffvelcdmda ⊢ φ ∧ x ∈ I → S ⁡ x ∈ SubGrp ⁡ G
17 2 3 4 5 dprdfcl ⊢ φ ∧ x ∈ I → F ⁡ x ∈ S ⁡ x
18 6 subginvcl ⊢ S ⁡ x ∈ SubGrp ⁡ G ∧ F ⁡ x ∈ S ⁡ x → N ⁡ F ⁡ x ∈ S ⁡ x
19 16 17 18 syl2anc ⊢ φ ∧ x ∈ I → N ⁡ F ⁡ x ∈ S ⁡ x
20 3 4 dprddomcld ⊢ φ → I ∈ V
21 20 mptexd ⊢ φ → x ∈ I ⟼ N ⁡ F ⁡ x ∈ V
22 funmpt ⊢ Fun ⁡ x ∈ I ⟼ N ⁡ F ⁡ x
23 22 a1i ⊢ φ → Fun ⁡ x ∈ I ⟼ N ⁡ F ⁡ x
24 2 3 4 5 dprdffsupp ⊢ φ → finSupp 0 ˙⁡ F
25 ssidd ⊢ φ → F supp 0 ˙ ⊆ F supp 0 ˙
26 1 fvexi ⊢ 0 ˙ ∈ V
27 26 a1i ⊢ φ → 0 ˙ ∈ V
28 12 25 20 27 suppssr ⊢ φ ∧ x ∈ I ∖ supp 0 ˙⁡ F → F ⁡ x = 0 ˙
29 28 fveq2d ⊢ φ ∧ x ∈ I ∖ supp 0 ˙⁡ F → N ⁡ F ⁡ x = N ⁡ 0 ˙
30 1 6 grpinvid ⊢ G ∈ Grp → N ⁡ 0 ˙ = 0 ˙
31 8 30 syl ⊢ φ → N ⁡ 0 ˙ = 0 ˙
32 31 adantr ⊢ φ ∧ x ∈ I ∖ supp 0 ˙⁡ F → N ⁡ 0 ˙ = 0 ˙
33 29 32 eqtrd ⊢ φ ∧ x ∈ I ∖ supp 0 ˙⁡ F → N ⁡ F ⁡ x = 0 ˙
34 33 20 suppss2 ⊢ φ → x ∈ I ⟼ N ⁡ F ⁡ x supp 0 ˙ ⊆ F supp 0 ˙
35 fsuppsssupp ⊢ x ∈ I ⟼ N ⁡ F ⁡ x ∈ V ∧ Fun ⁡ x ∈ I ⟼ N ⁡ F ⁡ x ∧ finSupp 0 ˙⁡ F ∧ x ∈ I ⟼ N ⁡ F ⁡ x supp 0 ˙ ⊆ F supp 0 ˙ → finSupp 0 ˙⁡ x ∈ I ⟼ N ⁡ F ⁡ x
36 21 23 24 34 35 syl22anc ⊢ φ → finSupp 0 ˙⁡ x ∈ I ⟼ N ⁡ F ⁡ x
37 2 3 4 19 36 dprdwd ⊢ φ → x ∈ I ⟼ N ⁡ F ⁡ x ∈ W
38 14 37 eqeltrd ⊢ φ → N ∘ F ∈ W
39 eqid ⊢ Cntz ⁡ G = Cntz ⁡ G
40 2 3 4 5 39 dprdfcntz ⊢ φ → ran ⁡ F ⊆ Cntz ⁡ G ⁡ ran ⁡ F
41 9 1 39 6 8 20 12 40 24 gsumzinv ⊢ φ → ∑ G N ∘ F = N ⁡ ∑ G F
42 38 41 jca ⊢ φ → N ∘ F ∈ W ∧ ∑ G N ∘ F = N ⁡ ∑ G F