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=BaseG
gsumzinv.0 0˙=0G
gsumzinv.z Z=CntzG
gsumzinv.i I=invgG
gsumzinv.g φGGrp
gsumzinv.a φAV
gsumzinv.f φF:AB
gsumzinv.c φranFZranF
gsumzinv.n φfinSupp0˙F
Assertion gsumzinv φGIF=IGF

Proof

Step Hyp Ref Expression
1 gsumzinv.b B=BaseG
2 gsumzinv.0 0˙=0G
3 gsumzinv.z Z=CntzG
4 gsumzinv.i I=invgG
5 gsumzinv.g φGGrp
6 gsumzinv.a φAV
7 gsumzinv.f φF:AB
8 gsumzinv.c φranFZranF
9 gsumzinv.n φfinSupp0˙F
10 eqid opp𝑔G=opp𝑔G
11 5 grpmndd φGMnd
12 1 4 grpinvf GGrpI:BB
13 5 12 syl φI:BB
14 fco I:BBF:ABIF:AB
15 13 7 14 syl2anc φIF:AB
16 10 4 invoppggim GGrpIGGrpIsoopp𝑔G
17 gimghm IGGrpIsoopp𝑔GIGGrpHomopp𝑔G
18 ghmmhm IGGrpHomopp𝑔GIGMndHomopp𝑔G
19 5 16 17 18 4syl φIGMndHomopp𝑔G
20 eqid Cntzopp𝑔G=Cntzopp𝑔G
21 3 20 cntzmhm2 IGMndHomopp𝑔GranFZranFIranFCntzopp𝑔GIranF
22 19 8 21 syl2anc φIranFCntzopp𝑔GIranF
23 rnco2 ranIF=IranF
24 23 fveq2i ZranIF=ZIranF
25 10 3 oppgcntz ZIranF=Cntzopp𝑔GIranF
26 24 25 eqtri ZranIF=Cntzopp𝑔GIranF
27 22 23 26 3sstr4g φranIFZranIF
28 2 fvexi 0˙V
29 28 a1i φ0˙V
30 1 fvexi BV
31 30 a1i φBV
32 2 4 grpinvid GGrpI0˙=0˙
33 5 32 syl φI0˙=0˙
34 29 7 13 6 31 9 33 fsuppco2 φfinSupp0˙IF
35 1 2 3 10 11 6 15 27 34 gsumzoppg φopp𝑔GIF=GIF
36 10 oppgmnd GMndopp𝑔GMnd
37 11 36 syl φopp𝑔GMnd
38 1 3 11 37 6 19 7 8 2 9 gsumzmhm φopp𝑔GIF=IGF
39 35 38 eqtr3d φGIF=IGF