Metamath Proof Explorer


Theorem gsumzinv

Description: Inverse of a group sum. (Contributed by Mario Carneiro, 25-Apr-2016) (Revised by AV, 6-Jun-2019)

Ref Expression
Hypotheses gsumzinv.b ⊢ B = Base G
gsumzinv.0 ⊢ 0 ˙ = 0 G
gsumzinv.z ⊢ Z = Cntz ⁡ G
gsumzinv.i ⊢ I = inv g ⁡ G
gsumzinv.g ⊢ φ → G ∈ Grp
gsumzinv.a ⊢ φ → A ∈ V
gsumzinv.f ⊢ φ → F : A ⟶ B
gsumzinv.c ⊢ φ → ran ⁡ F ⊆ Z ⁡ ran ⁡ F
gsumzinv.n ⊢ φ → finSupp 0 ˙⁡ F
Assertion gsumzinv ⊢ φ → ∑ G I ∘ F = I ⁡ ∑ G F

Proof

Step Hyp Ref Expression
1 gsumzinv.b ⊢ B = Base G
2 gsumzinv.0 ⊢ 0 ˙ = 0 G
3 gsumzinv.z ⊢ Z = Cntz ⁡ G
4 gsumzinv.i ⊢ I = inv g ⁡ G
5 gsumzinv.g ⊢ φ → G ∈ Grp
6 gsumzinv.a ⊢ φ → A ∈ V
7 gsumzinv.f ⊢ φ → F : A ⟶ B
8 gsumzinv.c ⊢ φ → ran ⁡ F ⊆ Z ⁡ ran ⁡ F
9 gsumzinv.n ⊢ φ → finSupp 0 ˙⁡ F
10 eqid ⊢ opp 𝑔 ⁡ G = opp 𝑔 ⁡ G
11 5 grpmndd ⊢ φ → G ∈ Mnd
12 1 4 grpinvf ⊢ G ∈ Grp → I : B ⟶ B
13 5 12 syl ⊢ φ → I : B ⟶ B
14 fco ⊢ I : B ⟶ B ∧ F : A ⟶ B → I ∘ F : A ⟶ B
15 13 7 14 syl2anc ⊢ φ → I ∘ F : A ⟶ B
16 10 4 invoppggim ⊢ G ∈ Grp → I ∈ G GrpIso opp 𝑔 ⁡ G
17 gimghm ⊢ I ∈ G GrpIso opp 𝑔 ⁡ G → I ∈ G GrpHom opp 𝑔 ⁡ G
18 ghmmhm ⊢ I ∈ G GrpHom opp 𝑔 ⁡ G → I ∈ G MndHom opp 𝑔 ⁡ G
19 5 16 17 18 4syl ⊢ φ → I ∈ G MndHom opp 𝑔 ⁡ G
20 eqid ⊢ Cntz ⁡ opp 𝑔 ⁡ G = Cntz ⁡ opp 𝑔 ⁡ G
21 3 20 cntzmhm2 ⊢ I ∈ G MndHom opp 𝑔 ⁡ G ∧ ran ⁡ F ⊆ Z ⁡ ran ⁡ F → I ran ⁡ F ⊆ Cntz ⁡ opp 𝑔 ⁡ G ⁡ I ran ⁡ F
22 19 8 21 syl2anc ⊢ φ → I ran ⁡ F ⊆ Cntz ⁡ opp 𝑔 ⁡ G ⁡ I ran ⁡ F
23 rnco2 ⊢ ran ⁡ I ∘ F = I ran ⁡ F
24 23 fveq2i ⊢ Z ⁡ ran ⁡ I ∘ F = Z ⁡ I ran ⁡ F
25 10 3 oppgcntz ⊢ Z ⁡ I ran ⁡ F = Cntz ⁡ opp 𝑔 ⁡ G ⁡ I ran ⁡ F
26 24 25 eqtri ⊢ Z ⁡ ran ⁡ I ∘ F = Cntz ⁡ opp 𝑔 ⁡ G ⁡ I ran ⁡ F
27 22 23 26 3sstr4g ⊢ φ → ran ⁡ I ∘ F ⊆ Z ⁡ ran ⁡ I ∘ F
28 2 fvexi ⊢ 0 ˙ ∈ V
29 28 a1i ⊢ φ → 0 ˙ ∈ V
30 1 fvexi ⊢ B ∈ V
31 30 a1i ⊢ φ → B ∈ V
32 2 4 grpinvid ⊢ G ∈ Grp → I ⁡ 0 ˙ = 0 ˙
33 5 32 syl ⊢ φ → I ⁡ 0 ˙ = 0 ˙
34 29 7 13 6 31 9 33 fsuppco2 ⊢ φ → finSupp 0 ˙⁡ I ∘ F
35 1 2 3 10 11 6 15 27 34 gsumzoppg ⊢ φ → ∑ opp 𝑔 ⁡ G I ∘ F = ∑ G I ∘ F
36 10 oppgmnd ⊢ G ∈ Mnd → opp 𝑔 ⁡ G ∈ Mnd
37 11 36 syl ⊢ φ → opp 𝑔 ⁡ G ∈ Mnd
38 1 3 11 37 6 19 7 8 2 9 gsumzmhm ⊢ φ → ∑ opp 𝑔 ⁡ G I ∘ F = I ⁡ ∑ G F
39 35 38 eqtr3d ⊢ φ → ∑ G I ∘ F = I ⁡ ∑ G F