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 | |
|
Assertion | lsm4 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | lsmcom.s | |
|
2 | simp1 | |
|
3 | simp2r | |
|
4 | simp3l | |
|
5 | 1 | lsmcom | |
6 | 2 3 4 5 | syl3anc | |
7 | 6 | oveq2d | |
8 | simp2l | |
|
9 | 1 | lsmass | |
10 | 8 3 4 9 | syl3anc | |
11 | 1 | lsmass | |
12 | 8 4 3 11 | syl3anc | |
13 | 7 10 12 | 3eqtr4d | |
14 | 13 | oveq1d | |
15 | 1 | lsmsubg2 | |
16 | 2 8 3 15 | syl3anc | |
17 | simp3r | |
|
18 | 1 | lsmass | |
19 | 16 4 17 18 | syl3anc | |
20 | 1 | lsmsubg2 | |
21 | 2 8 4 20 | syl3anc | |
22 | 1 | lsmass | |
23 | 21 3 17 22 | syl3anc | |
24 | 14 19 23 | 3eqtr3d | |