| Step | Hyp | Ref
| Expression |
| 1 | | frgrwopreg.v |
. . 3
Vtx   |
| 2 | | frgrwopreg.d |
. . 3
VtxDeg   |
| 3 | | frgrwopreg.a |
. . 3
       |
| 4 | | frgrwopreg.b |
. . 3
   |
| 5 | 1, 2, 3, 4 | frgrwopreglem1 27176 |
. 2
   |
| 6 | | hashv01gt1 13133 |
. . . 4
                 |
| 7 | | hasheq0 13154 |
. . . . . 6
     
   |
| 8 | | biidd 252 |
. . . . . 6
     
       |
| 9 | | biidd 252 |
. . . . . 6
 
           |
| 10 | 7, 8, 9 | 3orbi123d 1398 |
. . . . 5
               
             |
| 11 | | hashv01gt1 13133 |
. . . . . . 7
                 |
| 12 | | hasheq0 13154 |
. . . . . . . . 9
     
   |
| 13 | | biidd 252 |
. . . . . . . . 9
     
       |
| 14 | | biidd 252 |
. . . . . . . . 9
 
           |
| 15 | 12, 13, 14 | 3orbi123d 1398 |
. . . . . . . 8
               
             |
| 16 | | olc 399 |
. . . . . . . . . . 11

        |
| 17 | 16 | olcd 408 |
. . . . . . . . . 10

                |
| 18 | 17 | 2a1d 26 |
. . . . . . . . 9

          
 FriendGraph       
           |
| 19 | | orc 400 |
. . . . . . . . . . 11
             |
| 20 | 19 | olcd 408 |
. . . . . . . . . 10
                     |
| 21 | 20 | 2a1d 26 |
. . . . . . . . 9
                 FriendGraph                   |
| 22 | | olc 399 |
. . . . . . . . . . . . 13

        |
| 23 | 22 | orcd 407 |
. . . . . . . . . . . 12

                |
| 24 | 23 | 2a1d 26 |
. . . . . . . . . . 11

    
 FriendGraph       
           |
| 25 | | orc 400 |
. . . . . . . . . . . . 13
             |
| 26 | 25 | orcd 407 |
. . . . . . . . . . . 12
                     |
| 27 | 26 | 2a1d 26 |
. . . . . . . . . . 11
     
   
 FriendGraph       
           |
| 28 | | eqid 2622 |
. . . . . . . . . . . . . . 15
Edg  Edg   |
| 29 | 1, 2, 3, 4, 28 | frgrwopreglem5 27185 |
. . . . . . . . . . . . . 14
 
FriendGraph           


       Edg     Edg  
    Edg 
   Edg      |
| 30 | | frgrusgr 27124 |
. . . . . . . . . . . . . . . 16
 FriendGraph USGraph  |
| 31 | | simplll 798 |
. . . . . . . . . . . . . . . . . . . . . . 23
    USGraph 
  
 
  
USGraph  |
| 32 | | elrabi 3359 |
. . . . . . . . . . . . . . . . . . . . . . . . . 26
         |
| 33 | 32, 3 | eleq2s 2719 |
. . . . . . . . . . . . . . . . . . . . . . . . 25
   |
| 34 | 33 | adantr 481 |
. . . . . . . . . . . . . . . . . . . . . . . 24
 
   |
| 35 | 34 | ad3antlr 767 |
. . . . . . . . . . . . . . . . . . . . . . 23
    USGraph 
  
 
     |
| 36 | | rabidim1 3117 |
. . . . . . . . . . . . . . . . . . . . . . . . . 26
         |
| 37 | 36, 3 | eleq2s 2719 |
. . . . . . . . . . . . . . . . . . . . . . . . 25
   |
| 38 | 37 | adantl 482 |
. . . . . . . . . . . . . . . . . . . . . . . 24
 
   |
| 39 | 38 | ad3antlr 767 |
. . . . . . . . . . . . . . . . . . . . . . 23
    USGraph 
  
 
  
  |
| 40 | | simprl 794 |
. . . . . . . . . . . . . . . . . . . . . . 23
    USGraph 
  
 
     |
| 41 | | eldifi 3732 |
. . . . . . . . . . . . . . . . . . . . . . . . . 26
     |
| 42 | 41, 4 | eleq2s 2719 |
. . . . . . . . . . . . . . . . . . . . . . . . 25
   |
| 43 | 42 | adantr 481 |
. . . . . . . . . . . . . . . . . . . . . . . 24
 
   |
| 44 | 43 | ad2antlr 763 |
. . . . . . . . . . . . . . . . . . . . . . 23
    USGraph 
  
 
     |
| 45 | | eldifi 3732 |
. . . . . . . . . . . . . . . . . . . . . . . . . 26
     |
| 46 | 45, 4 | eleq2s 2719 |
. . . . . . . . . . . . . . . . . . . . . . . . 25
   |
| 47 | 46 | adantl 482 |
. . . . . . . . . . . . . . . . . . . . . . . 24
 
   |
| 48 | 47 | ad2antlr 763 |
. . . . . . . . . . . . . . . . . . . . . . 23
    USGraph 
  
 
     |
| 49 | | simprr 796 |
. . . . . . . . . . . . . . . . . . . . . . 23
    USGraph 
  
 
     |
| 50 | 1, 28 | 4cyclusnfrgr 27156 |
. . . . . . . . . . . . . . . . . . . . . . 23
  USGraph

 
        Edg     Edg  
    Edg 
   Edg   
FriendGraph   |
| 51 | 31, 35, 39, 40, 44, 48, 49, 50 | syl133anc 1349 |
. . . . . . . . . . . . . . . . . . . . . 22
    USGraph 
  
 
         Edg 
   Edg       Edg     Edg    FriendGraph   |
| 52 | 51 | exp4b 632 |
. . . . . . . . . . . . . . . . . . . . 21
   USGraph 
 

          Edg     Edg  
     Edg     Edg   FriendGraph     |
| 53 | 52 | 3impd 1281 |
. . . . . . . . . . . . . . . . . . . 20
   USGraph 
 

          Edg     Edg  
    Edg 
   Edg   
FriendGraph   |
| 54 | | df-nel 2898 |
. . . . . . . . . . . . . . . . . . . . 21
 FriendGraph FriendGraph  |
| 55 | | pm2.21 120 |
. . . . . . . . . . . . . . . . . . . . 21

FriendGraph
 FriendGraph       
          |
| 56 | 54, 55 | sylbi 207 |
. . . . . . . . . . . . . . . . . . . 20
 FriendGraph  FriendGraph       
          |
| 57 | 53, 56 | syl6 35 |
. . . . . . . . . . . . . . . . . . 19
   USGraph 
 

          Edg     Edg  
    Edg 
   Edg   
 FriendGraph       
           |
| 58 | 57 | rexlimdvva 3038 |
. . . . . . . . . . . . . . . . . 18
  USGraph

 
 

 

    Edg 
   Edg       Edg     Edg     FriendGraph                   |
| 59 | 58 | rexlimdvva 3038 |
. . . . . . . . . . . . . . . . 17
 USGraph  



       Edg     Edg  
    Edg 
   Edg   
 FriendGraph       
           |
| 60 | 59 | com23 86 |
. . . . . . . . . . . . . . . 16
 USGraph  FriendGraph             Edg     Edg  
    Edg 
   Edg   
                  |
| 61 | 30, 60 | mpcom 38 |
. . . . . . . . . . . . . . 15
 FriendGraph  



       Edg     Edg  
    Edg 
   Edg   
                 |
| 62 | 61 | 3ad2ant1 1082 |
. . . . . . . . . . . . . 14
 
FriendGraph           



       Edg     Edg  
    Edg 
   Edg   
                 |
| 63 | 29, 62 | mpd 15 |
. . . . . . . . . . . . 13
 
FriendGraph                          |
| 64 | 63 | 3exp 1264 |
. . . . . . . . . . . 12
 FriendGraph                             |
| 65 | 64 | com3l 89 |
. . . . . . . . . . 11
    
    
 FriendGraph       
           |
| 66 | 24, 27, 65 | 3jaoi 1391 |
. . . . . . . . . 10
          
    
 FriendGraph       
           |
| 67 | 66 | com12 32 |
. . . . . . . . 9
    
 
        
 FriendGraph       
           |
| 68 | 18, 21, 67 | 3jaoi 1391 |
. . . . . . . 8
          
 
        
 FriendGraph       
           |
| 69 | 15, 68 | syl6bi 243 |
. . . . . . 7
                            FriendGraph                    |
| 70 | 11, 69 | mpd 15 |
. . . . . 6
             FriendGraph                   |
| 71 | 70 | com12 32 |
. . . . 5
          

 FriendGraph       
           |
| 72 | 10, 71 | syl6bi 243 |
. . . 4
                  FriendGraph                    |
| 73 | 6, 72 | mpd 15 |
. . 3
 

FriendGraph
                  |
| 74 | 73 | imp 445 |
. 2
 
  FriendGraph                  |
| 75 | 5, 74 | ax-mp 5 |
1
 FriendGraph                 |