| Step | Hyp | Ref
| Expression |
| 1 | | unitmulcl.1 |
. . . 4
Unit   |
| 2 | | unitgrp.2 |
. . . 4
 mulGrp  ↾s   |
| 3 | 1, 2 | unitgrpbas 18666 |
. . 3
     |
| 4 | 3 | a1i 11 |
. 2

      |
| 5 | | fvex 6201 |
. . . 4
     |
| 6 | 3, 5 | eqeltri 2697 |
. . 3
 |
| 7 | | eqid 2622 |
. . . . 5
mulGrp  mulGrp   |
| 8 | | eqid 2622 |
. . . . 5
         |
| 9 | 7, 8 | mgpplusg 18493 |
. . . 4
      mulGrp    |
| 10 | 2, 9 | ressplusg 15993 |
. . 3
          |
| 11 | 6, 10 | mp1i 13 |
. 2

         |
| 12 | 1, 8 | unitmulcl 18664 |
. 2
 
           |
| 13 | | eqid 2622 |
. . . . 5
         |
| 14 | 13, 1 | unitcl 18659 |
. . . 4
       |
| 15 | 13, 1 | unitcl 18659 |
. . . 4
       |
| 16 | 13, 1 | unitcl 18659 |
. . . 4
       |
| 17 | 14, 15, 16 | 3anim123i 1247 |
. . 3
 
     
   
       |
| 18 | 13, 8 | ringass 18564 |
. . 3
          
                                        |
| 19 | 17, 18 | sylan2 491 |
. 2
  
 
                                  |
| 20 | | eqid 2622 |
. . 3
         |
| 21 | 1, 20 | 1unit 18658 |
. 2

      |
| 22 | 13, 8, 20 | ringlidm 18571 |
. . 3
                     |
| 23 | 14, 22 | sylan2 491 |
. 2
                 |
| 24 | | simpr 477 |
. . . 4
     |
| 25 | | eqid 2622 |
. . . . 5
 r   r   |
| 26 | | eqid 2622 |
. . . . 5
oppr  oppr   |
| 27 | | eqid 2622 |
. . . . 5
 r oppr    r oppr    |
| 28 | 1, 20, 25, 26, 27 | isunit 18657 |
. . . 4

   r         r oppr           |
| 29 | 24, 28 | sylib 208 |
. . 3
      r         r oppr           |
| 30 | 14 | adantl 482 |
. . . . . 6
         |
| 31 | 13, 25, 8 | dvdsr2 18647 |
. . . . . 6
    
   r       
                    |
| 32 | 30, 31 | syl 17 |
. . . . 5
      r       
                    |
| 33 | 26, 13 | opprbas 18629 |
. . . . . . 7
       oppr    |
| 34 | | eqid 2622 |
. . . . . . 7
   oppr      oppr    |
| 35 | 33, 27, 34 | dvdsr2 18647 |
. . . . . 6
    
   r oppr                   oppr            |
| 36 | 30, 35 | syl 17 |
. . . . 5
      r oppr                   oppr            |
| 37 | 32, 36 | anbi12d 747 |
. . . 4
       r         r oppr        
 
                
           oppr             |
| 38 | | reeanv 3107 |
. . . . 5
                         
     oppr         
 
                
           oppr            |
| 39 | | simprl 794 |
. . . . . . . . . . . 12
    
    
    
                  oppr                  |
| 40 | 30 | ad2antrr 762 |
. . . . . . . . . . . 12
    
    
    
                  oppr                  |
| 41 | 13, 25, 8 | dvdsrmul 18648 |
. . . . . . . . . . . 12
             r             |
| 42 | 39, 40, 41 | syl2anc 693 |
. . . . . . . . . . 11
    
    
    
                  oppr              r             |
| 43 | | simplll 798 |
. . . . . . . . . . . . . 14
    
    
    
                  oppr              |
| 44 | | simplr 792 |
. . . . . . . . . . . . . 14
    
    
    
                  oppr                  |
| 45 | 13, 8 | ringass 18564 |
. . . . . . . . . . . . . 14
          
                                        |
| 46 | 43, 44, 40, 39, 45 | syl13anc 1328 |
. . . . . . . . . . . . 13
    
    
    
                  oppr                                              |
| 47 | | simprrl 804 |
. . . . . . . . . . . . . 14
    
    
    
                  oppr                          |
| 48 | 47 | oveq1d 6665 |
. . . . . . . . . . . . 13
    
    
    
                  oppr                                          |
| 49 | 13, 8, 26, 34 | opprmul 18626 |
. . . . . . . . . . . . . . 15
     oppr              |
| 50 | | simprrr 805 |
. . . . . . . . . . . . . . 15
    
    
    
                  oppr                 oppr           |
| 51 | 49, 50 | syl5eqr 2670 |
. . . . . . . . . . . . . 14
    
    
    
                  oppr                          |
| 52 | 51 | oveq2d 6666 |
. . . . . . . . . . . . 13
    
    
    
                  oppr                                          |
| 53 | 46, 48, 52 | 3eqtr3d 2664 |
. . . . . . . . . . . 12
    
    
    
                  oppr                                      |
| 54 | 13, 8, 20 | ringlidm 18571 |
. . . . . . . . . . . . 13
                     |
| 55 | 43, 39, 54 | syl2anc 693 |
. . . . . . . . . . . 12
    
    
    
                  oppr                          |
| 56 | 13, 8, 20 | ringridm 18572 |
. . . . . . . . . . . . 13
                     |
| 57 | 43, 44, 56 | syl2anc 693 |
. . . . . . . . . . . 12
    
    
    
                  oppr                          |
| 58 | 53, 55, 57 | 3eqtr3d 2664 |
. . . . . . . . . . 11
    
    
    
                  oppr              |
| 59 | 42, 58, 51 | 3brtr3d 4684 |
. . . . . . . . . 10
    
    
    
                  oppr              r         |
| 60 | 33, 27, 34 | dvdsrmul 18648 |
. . . . . . . . . . . 12
             r oppr         oppr       |
| 61 | 44, 40, 60 | syl2anc 693 |
. . . . . . . . . . 11
    
    
    
                  oppr              r oppr         oppr       |
| 62 | 13, 8, 26, 34 | opprmul 18626 |
. . . . . . . . . . . 12
     oppr              |
| 63 | 62, 47 | syl5eq 2668 |
. . . . . . . . . . 11
    
    
    
                  oppr                 oppr           |
| 64 | 61, 63 | breqtrd 4679 |
. . . . . . . . . 10
    
    
    
                  oppr              r oppr          |
| 65 | 1, 20, 25, 26, 27 | isunit 18657 |
. . . . . . . . . 10

   r         r oppr           |
| 66 | 59, 64, 65 | sylanbrc 698 |
. . . . . . . . 9
    
    
    
                  oppr              |
| 67 | 66, 47 | jca 554 |
. . . . . . . 8
    
    
    
                  oppr                            |
| 68 | 67 | rexlimdvaa 3032 |
. . . . . . 7
        
 
                       oppr                           |
| 69 | 68 | expimpd 629 |
. . . . . 6
                                 oppr                            |
| 70 | 69 | reximdv2 3014 |
. . . . 5
    
                             oppr                          |
| 71 | 38, 70 | syl5bir 233 |
. . . 4
                                  oppr          
               |
| 72 | 37, 71 | sylbid 230 |
. . 3
       r         r oppr         
               |
| 73 | 29, 72 | mpd 15 |
. 2
   
              |
| 74 | 4, 11, 12, 19, 21, 23, 73 | isgrpde 17443 |
1

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