| Step | Hyp | Ref
| Expression |
| 1 | | uspgrupgr 26071 |
. . 3
 USPGraph UPGraph  |
| 2 | | wlknwwlksnbij.t |
. . . 4
 Walks            |
| 3 | | wlknwwlksnbij.w |
. . . 4
 WWalksN
  |
| 4 | | wlknwwlksnbij.f |
. . . 4
       |
| 5 | 2, 3, 4 | wlknwwlksnfun 26774 |
. . 3
  UPGraph
       |
| 6 | 1, 5 | sylan 488 |
. 2
  USPGraph
       |
| 7 | 3 | eleq2i 2693 |
. . . 4


WWalksN    |
| 8 | | wlklnwwlkn 26770 |
. . . . . . . . . . 11
 USPGraph      Walks       

WWalksN     |
| 9 | 8 | adantr 481 |
. . . . . . . . . 10
  USPGraph
      Walks       

WWalksN     |
| 10 | | df-br 4654 |
. . . . . . . . . . . 12
  Walks      Walks    |
| 11 | | vex 3203 |
. . . . . . . . . . . . . . . 16
 |
| 12 | | vex 3203 |
. . . . . . . . . . . . . . . 16
 |
| 13 | 11, 12 | op1st 7176 |
. . . . . . . . . . . . . . 15
        |
| 14 | 13 | eqcomi 2631 |
. . . . . . . . . . . . . 14
        |
| 15 | 14 | fveq2i 6194 |
. . . . . . . . . . . . 13
                |
| 16 | 15 | eqeq1i 2627 |
. . . . . . . . . . . 12
    
             |
| 17 | | elex 3212 |
. . . . . . . . . . . . . 14
    Walks       |
| 18 | | eleq1 2689 |
. . . . . . . . . . . . . . . . . 18
     Walks     Walks     |
| 19 | 18 | biimparc 504 |
. . . . . . . . . . . . . . . . 17
     Walks 
    Walks    |
| 20 | 19 | adantr 481 |
. . . . . . . . . . . . . . . 16
      Walks 
               
Walks    |
| 21 | | fveq2 6191 |
. . . . . . . . . . . . . . . . . . . 20
                 |
| 22 | 21 | fveq2d 6195 |
. . . . . . . . . . . . . . . . . . 19
                         |
| 23 | 22 | eqeq1d 2624 |
. . . . . . . . . . . . . . . . . 18
                           |
| 24 | 23 | adantl 482 |
. . . . . . . . . . . . . . . . 17
     Walks 
            
              |
| 25 | 24 | biimpar 502 |
. . . . . . . . . . . . . . . 16
      Walks 
               
          |
| 26 | | fveq2 6191 |
. . . . . . . . . . . . . . . . . . 19
                 |
| 27 | 11, 12 | op2nd 7177 |
. . . . . . . . . . . . . . . . . . 19
        |
| 28 | 26, 27 | syl6req 2673 |
. . . . . . . . . . . . . . . . . 18
          |
| 29 | 28 | adantl 482 |
. . . . . . . . . . . . . . . . 17
     Walks 
          |
| 30 | 29 | adantr 481 |
. . . . . . . . . . . . . . . 16
      Walks 
               
      |
| 31 | 20, 25, 30 | jca31 557 |
. . . . . . . . . . . . . . 15
      Walks 
               
  Walks                  |
| 32 | 31 | ex 450 |
. . . . . . . . . . . . . 14
     Walks 
                  Walks 
        
        |
| 33 | 17, 32 | spcimedv 3292 |
. . . . . . . . . . . . 13
    Walks                  Walks                   |
| 34 | 33 | imp 445 |
. . . . . . . . . . . 12
     Walks             
    Walks          
       |
| 35 | 10, 16, 34 | syl2anb 496 |
. . . . . . . . . . 11
   Walks            Walks          
       |
| 36 | 35 | exlimiv 1858 |
. . . . . . . . . 10
     Walks            Walks 
        
       |
| 37 | 9, 36 | syl6bir 244 |
. . . . . . . . 9
  USPGraph
   WWalksN      Walks          
        |
| 38 | 37 | imp 445 |
. . . . . . . 8
   USPGraph   WWalksN
 
    Walks          
       |
| 39 | | fveq2 6191 |
. . . . . . . . . . . . 13
           |
| 40 | 39 | fveq2d 6195 |
. . . . . . . . . . . 12
                   |
| 41 | 40 | eqeq1d 2624 |
. . . . . . . . . . 11
                     |
| 42 | 41 | elrab 3363 |
. . . . . . . . . 10
  Walks          
 Walks             |
| 43 | 42 | anbi1i 731 |
. . . . . . . . 9
   Walks          
    
  Walks                  |
| 44 | 43 | exbii 1774 |
. . . . . . . 8
     Walks               
    Walks          
       |
| 45 | 38, 44 | sylibr 224 |
. . . . . . 7
   USPGraph   WWalksN
 
    Walks                  |
| 46 | | df-rex 2918 |
. . . . . . 7
   Walks                    Walks          
       |
| 47 | 45, 46 | sylibr 224 |
. . . . . 6
   USPGraph   WWalksN
 
  Walks                  |
| 48 | 2 | rexeqi 3143 |
. . . . . 6
        Walks                  |
| 49 | 47, 48 | sylibr 224 |
. . . . 5
   USPGraph   WWalksN
 

      |
| 50 | | fveq2 6191 |
. . . . . . . 8
           |
| 51 | | fvex 6201 |
. . . . . . . 8
     |
| 52 | 50, 4, 51 | fvmpt 6282 |
. . . . . . 7
           |
| 53 | 52 | eqeq2d 2632 |
. . . . . 6
     
       |
| 54 | 53 | rexbiia 3040 |
. . . . 5
     

      |
| 55 | 49, 54 | sylibr 224 |
. . . 4
   USPGraph   WWalksN
 

      |
| 56 | 7, 55 | sylan2b 492 |
. . 3
   USPGraph   
      |
| 57 | 56 | ralrimiva 2966 |
. 2
  USPGraph
 

      |
| 58 | | dffo3 6374 |
. 2
    
     

       |
| 59 | 6, 57, 58 | sylanbrc 698 |
1
  USPGraph
       |