Proof of Theorem gxcom
| Step | Hyp | Ref
| Expression |
| 1 | | opreq2 4890 |
. . . . 5
           |
| 2 | 1 | opreq1d 4897 |
. . . 4
                   |
| 3 | 1 | opreq2d 4898 |
. . . 4
                   |
| 4 | 2, 3 | eqeq12d 1899 |
. . 3
                                     |
| 5 | | opreq2 4890 |
. . . . 5
           |
| 6 | 5 | opreq1d 4897 |
. . . 4
                   |
| 7 | 5 | opreq2d 4898 |
. . . 4
                   |
| 8 | 6, 7 | eqeq12d 1899 |
. . 3
                                     |
| 9 | | opreq2 4890 |
. . . . 5
               |
| 10 | 9 | opreq1d 4897 |
. . . 4
                       |
| 11 | 9 | opreq2d 4898 |
. . . 4
                       |
| 12 | 10, 11 | eqeq12d 1899 |
. . 3
                                           |
| 13 | | opreq2 4890 |
. . . . 5
             |
| 14 | 13 | opreq1d 4897 |
. . . 4
                     |
| 15 | 13 | opreq2d 4898 |
. . . 4
                     |
| 16 | 14, 15 | eqeq12d 1899 |
. . 3
                                        |
| 17 | | opreq2 4890 |
. . . . 5
           |
| 18 | 17 | opreq1d 4897 |
. . . 4
                   |
| 19 | 17 | opreq2d 4898 |
. . . 4
                   |
| 20 | 18, 19 | eqeq12d 1899 |
. . 3
                                     |
| 21 | | gxcom.1 |
. . . . . . 7
 |
| 22 | | eqid 1884 |
. . . . . . 7
Id  Id   |
| 23 | | gxcom.2 |
. . . . . . 7
     |
| 24 | 21, 22, 23 | gx0 9384 |
. . . . . 6
  Grp
     Id    |
| 25 | 24 | opreq1d 4897 |
. . . . 5
  Grp
          Id       |
| 26 | 21, 22 | grplid 9345 |
. . . . 5
  Grp
  Id       |
| 27 | 25, 26 | eqtrd 1925 |
. . . 4
  Grp
           |
| 28 | 24 | opreq2d 4898 |
. . . . 5
  Grp
            Id     |
| 29 | 21, 22 | grprid 9346 |
. . . . 5
  Grp
    Id     |
| 30 | 28, 29 | eqtrd 1925 |
. . . 4
  Grp
           |
| 31 | 27, 30 | eqtr4d 1928 |
. . 3
  Grp
                   |
| 32 | | simp1 876 |
. . . . . . . . 9
  Grp

Grp |
| 33 | | simp2 877 |
. . . . . . . . 9
  Grp

  |
| 34 | 21, 23 | gxcl 9388 |
. . . . . . . . 9
  Grp
       |
| 35 | 21 | grpass 9327 |
. . . . . . . . 9
  Grp                                  |
| 36 | 32, 33, 34, 33, 35 | syl13anc 1102 |
. . . . . . . 8
  Grp
                           |
| 37 | | nn0z 7363 |
. . . . . . . 8

  |
| 38 | 36, 37 | syl3an3 1132 |
. . . . . . 7
  Grp
                           |
| 39 | 38 | adantr 425 |
. . . . . 6
   Grp

                                           |
| 40 | 21, 23 | gxnn0suc 9387 |
. . . . . . . . 9
  Grp
                 |
| 41 | 40 | eqeq1d 1892 |
. . . . . . . 8
  Grp
                                   |
| 42 | 41 | biimpar 461 |
. . . . . . 7
   Grp

                                 |
| 43 | 42 | opreq1d 4897 |
. . . . . 6
   Grp

                                         |
| 44 | 40 | opreq2d 4898 |
. . . . . . 7
  Grp
                         |
| 45 | 44 | adantr 425 |
. . . . . 6
   Grp

                                         |
| 46 | 39, 43, 45 | 3eqtr4d 1937 |
. . . . 5
   Grp

                                       |
| 47 | 46 | ex 402 |
. . . 4
  Grp
                                         |
| 48 | 47 | 3expia 1069 |
. . 3
  Grp
                                           |
| 49 | | simpl1 879 |
. . . . . . . . . 10
   Grp
                  Grp |
| 50 | | simpl2 880 |
. . . . . . . . . 10
   Grp
                    |
| 51 | | simpl3 881 |
. . . . . . . . . . 11
   Grp
                    |
| 52 | 21, 23 | gxcl 9388 |
. . . . . . . . . . . 12
  Grp
         |
| 53 | | znegcl 7372 |
. . . . . . . . . . . 12
    |
| 54 | 52, 53 | syl3an3 1132 |
. . . . . . . . . . 11
  Grp
        |
| 55 | 49, 50, 51, 54 | syl111anc 1100 |
. . . . . . . . . 10
   Grp
                         |
| 56 | | eqid 1884 |
. . . . . . . . . . . 12
inv  inv   |
| 57 | 21, 56 | grpinvcl 9352 |
. . . . . . . . . . 11
  Grp
  inv       |
| 58 | 49, 50, 57 | syl11anc 524 |
. . . . . . . . . 10
   Grp
                   inv       |
| 59 | 21 | grpass 9327 |
. . . . . . . . . 10
  Grp        inv                    inv                  inv         |
| 60 | 49, 50, 55, 58, 59 | syl13anc 1102 |
. . . . . . . . 9
   Grp
                               inv                  inv         |
| 61 | | fveq2 4681 |
. . . . . . . . . . . 12
                  inv              inv               |
| 62 | 61 | adantl 424 |
. . . . . . . . . . 11
   Grp
                   inv              inv               |
| 63 | 49, 50, 51, 34 | syl111anc 1100 |
. . . . . . . . . . . . 13
   Grp
                        |
| 64 | 21, 56 | grpinvop 9365 |
. . . . . . . . . . . . 13
  Grp    
  inv               inv        inv            |
| 65 | 49, 63, 50, 64 | syl111anc 1100 |
. . . . . . . . . . . 12
   Grp
                   inv               inv        inv            |
| 66 | 21, 56, 23 | gxneg 9389 |
. . . . . . . . . . . . . 14
  Grp
       inv           |
| 67 | 49, 50, 51, 66 | syl111anc 1100 |
. . . . . . . . . . . . 13
   Grp
                        inv           |
| 68 | 67 | opreq2d 4898 |
. . . . . . . . . . . 12
   Grp
                    inv               inv        inv            |
| 69 | 65, 68 | eqtr4d 1928 |
. . . . . . . . . . 11
   Grp
                   inv               inv               |
| 70 | 21, 56 | grpinvop 9365 |
. . . . . . . . . . . . 13
  Grp
      inv               inv            inv        |
| 71 | 49, 50, 63, 70 | syl111anc 1100 |
. . . . . . . . . . . 12
   Grp
                   inv               inv            inv        |
| 72 | 67 | opreq1d 4897 |
. . . . . . . . . . . 12
   Grp
                           inv        inv            inv        |
| 73 | 71, 72 | eqtr4d 1928 |
. . . . . . . . . . 11
   Grp
                   inv                      inv        |
| 74 | 62, 69, 73 | 3eqtr3rd 1936 |
. . . . . . . . . 10
   Grp
                           inv        inv               |
| 75 | 74 | opreq2d 4898 |
. . . . . . . . 9
   Grp
                              inv            inv                |
| 76 | 21, 56 | grpasscan1 9361 |
. . . . . . . . . 10
  Grp
           inv                     |
| 77 | 49, 50, 55, 76 | syl111anc 1100 |
. . . . . . . . 9
   Grp
                       inv                     |
| 78 | 60, 75, 77 | 3eqtrd 1929 |
. . . . . . . 8
   Grp
                               inv             |
| 79 | 78 | opreq1d 4897 |
. . . . . . 7
   Grp
                                inv                    |
| 80 | 21 | grpcl 9324 |
. . . . . . . . 9
  Grp
                 |
| 81 | 49, 50, 55, 80 | syl111anc 1100 |
. . . . . . . 8
   Grp
                             |
| 82 | 21, 56 | grpasscan2 9362 |
. . . . . . . 8
  Grp                         inv                    |
| 83 | 49, 81, 50, 82 | syl111anc 1100 |
. . . . . . 7
   Grp
                                inv                    |
| 84 | 79, 83 | eqtr3d 1927 |
. . . . . 6
   Grp
                                      |
| 85 | 84 | ex 402 |
. . . . 5
  Grp
                                       |
| 86 | 85 | 3expia 1069 |
. . . 4
  Grp
                                         |
| 87 | | nnz 7362 |
. . . 4
   |
| 88 | 86, 87 | syl5 20 |
. . 3
  Grp
                                         |
| 89 | 4, 8, 12, 16, 20, 31, 48, 88 | zindd 7427 |
. 2
  Grp
                     |
| 90 | 89 | 3impia 1064 |
1
  Grp
                   |