Description: R is an (additive) group. (Contributed by AV, 6-Jan-2020)
Ref | Expression | ||
---|---|---|---|
Hypotheses | 2zrng.e | |
|
2zrngbas.r | |
||
Assertion | 2zrngagrp | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 2zrng.e | |
|
2 | 2zrngbas.r | |
|
3 | 1 2 | 2zrngamnd | |
4 | eqeq1 | |
|
5 | 4 | rexbidv | |
6 | 5 1 | elrab2 | |
7 | znegcl | |
|
8 | 7 | adantr | |
9 | nfv | |
|
10 | nfre1 | |
|
11 | znegcl | |
|
12 | 11 | adantl | |
13 | 12 | adantr | |
14 | oveq2 | |
|
15 | 14 | eqeq2d | |
16 | 15 | adantl | |
17 | negeq | |
|
18 | 2cnd | |
|
19 | zcn | |
|
20 | 18 19 | mulneg2d | |
21 | 20 | eqcomd | |
22 | 21 | adantl | |
23 | 17 22 | sylan9eqr | |
24 | 13 16 23 | rspcedvd | |
25 | oveq2 | |
|
26 | 25 | eqeq2d | |
27 | 26 | cbvrexvw | |
28 | 24 27 | sylibr | |
29 | 28 | exp31 | |
30 | 9 10 29 | rexlimd | |
31 | 30 | imp | |
32 | eqeq1 | |
|
33 | 32 | rexbidv | |
34 | 33 1 | elrab2 | |
35 | 8 31 34 | sylanbrc | |
36 | 6 35 | sylbi | |
37 | oveq1 | |
|
38 | 37 | eqeq1d | |
39 | 38 | adantl | |
40 | elrabi | |
|
41 | 40 1 | eleq2s | |
42 | 41 | zcnd | |
43 | 42 | negcld | |
44 | 43 42 | addcomd | |
45 | 42 | negidd | |
46 | 44 45 | eqtrd | |
47 | 36 39 46 | rspcedvd | |
48 | 47 | rgen | |
49 | 1 2 | 2zrngbas | |
50 | 1 2 | 2zrngadd | |
51 | 1 2 | 2zrng0 | |
52 | 49 50 51 | isgrp | |
53 | 3 48 52 | mpbir2an | |