Metamath Proof Explorer


Theorem lsm4

Description: Commutative/associative law for subgroup sum. (Contributed by NM, 26-Sep-2014) (Revised by Mario Carneiro, 19-Apr-2016)

Ref Expression
Hypothesis lsmcom.s ˙ = LSSum G
Assertion lsm4 G Abel Q SubGrp G R SubGrp G T SubGrp G U SubGrp G Q ˙ R ˙ T ˙ U = Q ˙ T ˙ R ˙ U

Proof

Step Hyp Ref Expression
1 lsmcom.s ˙ = LSSum G
2 simp1 G Abel Q SubGrp G R SubGrp G T SubGrp G U SubGrp G G Abel
3 simp2r G Abel Q SubGrp G R SubGrp G T SubGrp G U SubGrp G R SubGrp G
4 simp3l G Abel Q SubGrp G R SubGrp G T SubGrp G U SubGrp G T SubGrp G
5 1 lsmcom G Abel R SubGrp G T SubGrp G R ˙ T = T ˙ R
6 2 3 4 5 syl3anc G Abel Q SubGrp G R SubGrp G T SubGrp G U SubGrp G R ˙ T = T ˙ R
7 6 oveq2d G Abel Q SubGrp G R SubGrp G T SubGrp G U SubGrp G Q ˙ R ˙ T = Q ˙ T ˙ R
8 simp2l G Abel Q SubGrp G R SubGrp G T SubGrp G U SubGrp G Q SubGrp G
9 1 lsmass Q SubGrp G R SubGrp G T SubGrp G Q ˙ R ˙ T = Q ˙ R ˙ T
10 8 3 4 9 syl3anc G Abel Q SubGrp G R SubGrp G T SubGrp G U SubGrp G Q ˙ R ˙ T = Q ˙ R ˙ T
11 1 lsmass Q SubGrp G T SubGrp G R SubGrp G Q ˙ T ˙ R = Q ˙ T ˙ R
12 8 4 3 11 syl3anc G Abel Q SubGrp G R SubGrp G T SubGrp G U SubGrp G Q ˙ T ˙ R = Q ˙ T ˙ R
13 7 10 12 3eqtr4d G Abel Q SubGrp G R SubGrp G T SubGrp G U SubGrp G Q ˙ R ˙ T = Q ˙ T ˙ R
14 13 oveq1d G Abel Q SubGrp G R SubGrp G T SubGrp G U SubGrp G Q ˙ R ˙ T ˙ U = Q ˙ T ˙ R ˙ U
15 1 lsmsubg2 G Abel Q SubGrp G R SubGrp G Q ˙ R SubGrp G
16 2 8 3 15 syl3anc G Abel Q SubGrp G R SubGrp G T SubGrp G U SubGrp G Q ˙ R SubGrp G
17 simp3r G Abel Q SubGrp G R SubGrp G T SubGrp G U SubGrp G U SubGrp G
18 1 lsmass Q ˙ R SubGrp G T SubGrp G U SubGrp G Q ˙ R ˙ T ˙ U = Q ˙ R ˙ T ˙ U
19 16 4 17 18 syl3anc G Abel Q SubGrp G R SubGrp G T SubGrp G U SubGrp G Q ˙ R ˙ T ˙ U = Q ˙ R ˙ T ˙ U
20 1 lsmsubg2 G Abel Q SubGrp G T SubGrp G Q ˙ T SubGrp G
21 2 8 4 20 syl3anc G Abel Q SubGrp G R SubGrp G T SubGrp G U SubGrp G Q ˙ T SubGrp G
22 1 lsmass Q ˙ T SubGrp G R SubGrp G U SubGrp G Q ˙ T ˙ R ˙ U = Q ˙ T ˙ R ˙ U
23 21 3 17 22 syl3anc G Abel Q SubGrp G R SubGrp G T SubGrp G U SubGrp G Q ˙ T ˙ R ˙ U = Q ˙ T ˙ R ˙ U
24 14 19 23 3eqtr3d G Abel Q SubGrp G R SubGrp G T SubGrp G U SubGrp G Q ˙ R ˙ T ˙ U = Q ˙ T ˙ R ˙ U