Metamath Proof Explorer


Theorem 2zrngagrp

Description: R is an (additive) group. (Contributed by AV, 6-Jan-2020)

Ref Expression
Hypotheses 2zrng.e E=z|xz=2x
2zrngbas.r R=fld𝑠E
Assertion 2zrngagrp RGrp

Proof

Step Hyp Ref Expression
1 2zrng.e E=z|xz=2x
2 2zrngbas.r R=fld𝑠E
3 1 2 2zrngamnd RMnd
4 eqeq1 z=yz=2xy=2x
5 4 rexbidv z=yxz=2xxy=2x
6 5 1 elrab2 yEyxy=2x
7 znegcl yy
8 7 adantr yxy=2xy
9 nfv xy
10 nfre1 xxy=2x
11 znegcl xx
12 11 adantl yxx
13 12 adantr yxy=2xx
14 oveq2 z=x2z=2x
15 14 eqeq2d z=xy=2zy=2x
16 15 adantl yxy=2xz=xy=2zy=2x
17 negeq y=2xy=2x
18 2cnd x2
19 zcn xx
20 18 19 mulneg2d x2x=2x
21 20 eqcomd x2x=2x
22 21 adantl yx2x=2x
23 17 22 sylan9eqr yxy=2xy=2x
24 13 16 23 rspcedvd yxy=2xzy=2z
25 oveq2 x=z2x=2z
26 25 eqeq2d x=zy=2xy=2z
27 26 cbvrexvw xy=2xzy=2z
28 24 27 sylibr yxy=2xxy=2x
29 28 exp31 yxy=2xxy=2x
30 9 10 29 rexlimd yxy=2xxy=2x
31 30 imp yxy=2xxy=2x
32 eqeq1 z=yz=2xy=2x
33 32 rexbidv z=yxz=2xxy=2x
34 33 1 elrab2 yEyxy=2x
35 8 31 34 sylanbrc yxy=2xyE
36 6 35 sylbi yEyE
37 oveq1 z=yz+y=-y+y
38 37 eqeq1d z=yz+y=0-y+y=0
39 38 adantl yEz=yz+y=0-y+y=0
40 elrabi yz|xz=2xy
41 40 1 eleq2s yEy
42 41 zcnd yEy
43 42 negcld yEy
44 43 42 addcomd yE-y+y=y+y
45 42 negidd yEy+y=0
46 44 45 eqtrd yE-y+y=0
47 36 39 46 rspcedvd yEzEz+y=0
48 47 rgen yEzEz+y=0
49 1 2 2zrngbas E=BaseR
50 1 2 2zrngadd +=+R
51 1 2 2zrng0 0=0R
52 49 50 51 isgrp RGrpRMndyEzEz+y=0
53 3 48 52 mpbir2an RGrp