Description: A homomorphism of groups preserves inverses. (Contributed by Stefan O'Rear, 31-Dec-2014)
Ref | Expression | ||
---|---|---|---|
Hypotheses | ghminv.b | |
|
ghminv.y | |
||
ghminv.z | |
||
Assertion | ghminv | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ghminv.b | |
|
2 | ghminv.y | |
|
3 | ghminv.z | |
|
4 | ghmgrp1 | |
|
5 | eqid | |
|
6 | eqid | |
|
7 | 1 5 6 2 | grprinv | |
8 | 4 7 | sylan | |
9 | 8 | fveq2d | |
10 | 1 2 | grpinvcl | |
11 | 4 10 | sylan | |
12 | eqid | |
|
13 | 1 5 12 | ghmlin | |
14 | 11 13 | mpd3an3 | |
15 | eqid | |
|
16 | 6 15 | ghmid | |
17 | 16 | adantr | |
18 | 9 14 17 | 3eqtr3d | |
19 | ghmgrp2 | |
|
20 | 19 | adantr | |
21 | eqid | |
|
22 | 1 21 | ghmf | |
23 | 22 | ffvelcdmda | |
24 | 22 | adantr | |
25 | 24 11 | ffvelcdmd | |
26 | 21 12 15 3 | grpinvid1 | |
27 | 20 23 25 26 | syl3anc | |
28 | 18 27 | mpbird | |
29 | 28 | eqcomd | |