Description: Linearity of subtraction through a group homomorphism. (Contributed by Stefan O'Rear, 31-Dec-2014)
Ref | Expression | ||
---|---|---|---|
Hypotheses | ghmsub.b | |
|
ghmsub.m | |
||
ghmsub.n | |
||
Assertion | ghmsub | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ghmsub.b | |
|
2 | ghmsub.m | |
|
3 | ghmsub.n | |
|
4 | ghmgrp1 | |
|
5 | 4 | 3ad2ant1 | |
6 | simp3 | |
|
7 | eqid | |
|
8 | 1 7 | grpinvcl | |
9 | 5 6 8 | syl2anc | |
10 | eqid | |
|
11 | eqid | |
|
12 | 1 10 11 | ghmlin | |
13 | 9 12 | syld3an3 | |
14 | eqid | |
|
15 | 1 7 14 | ghminv | |
16 | 15 | 3adant2 | |
17 | 16 | oveq2d | |
18 | 13 17 | eqtrd | |
19 | 1 10 7 2 | grpsubval | |
20 | 19 | fveq2d | |
21 | 20 | 3adant1 | |
22 | eqid | |
|
23 | 1 22 | ghmf | |
24 | ffvelcdm | |
|
25 | ffvelcdm | |
|
26 | 24 25 | anim12dan | |
27 | 23 26 | sylan | |
28 | 27 | 3impb | |
29 | 22 11 14 3 | grpsubval | |
30 | 28 29 | syl | |
31 | 18 21 30 | 3eqtr4d | |