| Step | Hyp | Ref
| Expression |
| 1 | | eqidd 2623 |
. . 3
 
 
 WWalksN    substr
       substr         |
| 2 | | eqid 2622 |
. . . . 5
Vtx  Vtx   |
| 3 | | wwlksnredwwlkn.e |
. . . . 5
Edg   |
| 4 | 2, 3 | wwlknp 26734 |
. . . 4
    WWalksN 
 Word Vtx            ..^                    |
| 5 | | simprl 794 |
. . . . . . . . 9
  
Word Vtx           
Word Vtx    |
| 6 | | peano2nn0 11333 |
. . . . . . . . . . . . 13

    |
| 7 | | peano2nn0 11333 |
. . . . . . . . . . . . 13
  
      |
| 8 | 6, 7 | syl 17 |
. . . . . . . . . . . 12

      |
| 9 | | id 22 |
. . . . . . . . . . . . 13

  |
| 10 | | nn0p1nn 11332 |
. . . . . . . . . . . . . 14
  
      |
| 11 | 6, 10 | syl 17 |
. . . . . . . . . . . . 13

      |
| 12 | | nn0re 11301 |
. . . . . . . . . . . . . . 15

  |
| 13 | | id 22 |
. . . . . . . . . . . . . . . 16
   |
| 14 | | peano2re 10209 |
. . . . . . . . . . . . . . . 16
 
   |
| 15 | | peano2re 10209 |
. . . . . . . . . . . . . . . . 17
         |
| 16 | 14, 15 | syl 17 |
. . . . . . . . . . . . . . . 16
       |
| 17 | 13, 14, 16 | 3jca 1242 |
. . . . . . . . . . . . . . 15
 

        |
| 18 | 12, 17 | syl 17 |
. . . . . . . . . . . . . 14

 
        |
| 19 | 12 | ltp1d 10954 |
. . . . . . . . . . . . . 14

    |
| 20 | | nn0re 11301 |
. . . . . . . . . . . . . . . 16
  
    |
| 21 | 6, 20 | syl 17 |
. . . . . . . . . . . . . . 15

    |
| 22 | 21 | ltp1d 10954 |
. . . . . . . . . . . . . 14

        |
| 23 | | lttr 10114 |
. . . . . . . . . . . . . . 15
  
          
             |
| 24 | 23 | imp 445 |
. . . . . . . . . . . . . 14
                           |
| 25 | 18, 19, 22, 24 | syl12anc 1324 |
. . . . . . . . . . . . 13

      |
| 26 | | elfzo0 12508 |
. . . . . . . . . . . . 13
  ..^     
 
         |
| 27 | 9, 11, 25, 26 | syl3anbrc 1246 |
. . . . . . . . . . . 12

 ..^       |
| 28 | | fz0add1fz1 12537 |
. . . . . . . . . . . 12
     
 ..^                  |
| 29 | 8, 27, 28 | syl2anc 693 |
. . . . . . . . . . 11

            |
| 30 | 29 | adantr 481 |
. . . . . . . . . 10
  
Word Vtx                        |
| 31 | | oveq2 6658 |
. . . . . . . . . . . . 13
                           |
| 32 | 31 | eleq2d 2687 |
. . . . . . . . . . . 12
                   
             |
| 33 | 32 | adantl 482 |
. . . . . . . . . . 11
  Word Vtx                     
             |
| 34 | 33 | adantl 482 |
. . . . . . . . . 10
  
Word Vtx                      
             |
| 35 | 30, 34 | mpbird 247 |
. . . . . . . . 9
  
Word Vtx                        |
| 36 | 5, 35 | jca 554 |
. . . . . . . 8
  
Word Vtx             Word Vtx  
            |
| 37 | 36 | 3adantr3 1222 |
. . . . . . 7
  
Word Vtx            ..^                  
 Word Vtx               |
| 38 | | swrd0fvlsw 13443 |
. . . . . . 7
  Word Vtx  
          lastS   substr                  |
| 39 | 37, 38 | syl 17 |
. . . . . 6
  
Word Vtx            ..^                  
lastS   substr                  |
| 40 | | lsw 13351 |
. . . . . . . 8
 Word Vtx 
lastS               |
| 41 | 40 | 3ad2ant1 1082 |
. . . . . . 7
  Word Vtx            ..^                  lastS
              |
| 42 | 41 | adantl 482 |
. . . . . 6
  
Word Vtx            ..^                  
lastS               |
| 43 | 39, 42 | preq12d 4276 |
. . . . 5
  
Word Vtx            ..^                  
 lastS   substr         lastS                           |
| 44 | | oveq1 6657 |
. . . . . . . . . . 11
                       |
| 45 | 44 | 3ad2ant2 1083 |
. . . . . . . . . 10
  Word Vtx            ..^                                |
| 46 | 45 | adantl 482 |
. . . . . . . . 9
  
Word Vtx            ..^                  
              |
| 47 | 46 | fveq2d 6195 |
. . . . . . . 8
  
Word Vtx            ..^                  
                      |
| 48 | 47 | preq2d 4275 |
. . . . . . 7
  
Word Vtx            ..^                  
     
                                      |
| 49 | | nn0cn 11302 |
. . . . . . . . . . 11

  |
| 50 | | 1cnd 10056 |
. . . . . . . . . . 11

  |
| 51 | 49, 50 | pncand 10393 |
. . . . . . . . . 10

      |
| 52 | 51 | fveq2d 6195 |
. . . . . . . . 9

              |
| 53 | 6 | nn0cnd 11353 |
. . . . . . . . . . 11

    |
| 54 | 53, 50 | pncand 10393 |
. . . . . . . . . 10

          |
| 55 | 54 | fveq2d 6195 |
. . . . . . . . 9

             
    |
| 56 | 52, 55 | preq12d 4276 |
. . . . . . . 8

                                    |
| 57 | 56 | adantr 481 |
. . . . . . 7
  
Word Vtx            ..^                  
     
                              |
| 58 | 48, 57 | eqtrd 2656 |
. . . . . 6
  
Word Vtx            ..^                  
     
                              |
| 59 | | fveq2 6191 |
. . . . . . . . . . . 12
           |
| 60 | | oveq1 6657 |
. . . . . . . . . . . . 13
       |
| 61 | 60 | fveq2d 6195 |
. . . . . . . . . . . 12
          
    |
| 62 | 59, 61 | preq12d 4276 |
. . . . . . . . . . 11
                             |
| 63 | 62 | eleq1d 2686 |
. . . . . . . . . 10
              
         
      |
| 64 | 63 | rspcv 3305 |
. . . . . . . . 9
  ..^  
 
 ..^                          
      |
| 65 | | fzonn0p1 12544 |
. . . . . . . . 9

 ..^     |
| 66 | 64, 65 | syl11 33 |
. . . . . . . 8
 
 ..^                           
      |
| 67 | 66 | 3ad2ant3 1084 |
. . . . . . 7
  Word Vtx            ..^                            
      |
| 68 | 67 | impcom 446 |
. . . . . 6
  
Word Vtx            ..^                  
         
     |
| 69 | 58, 68 | eqeltrd 2701 |
. . . . 5
  
Word Vtx            ..^                  
     
                 |
| 70 | 43, 69 | eqeltrd 2701 |
. . . 4
  
Word Vtx            ..^                  
 lastS   substr         lastS      |
| 71 | 4, 70 | sylan2 491 |
. . 3
 
 
 WWalksN   
lastS   substr         lastS      |
| 72 | | wwlksnred 26787 |
. . . . 5

    WWalksN 
 substr        WWalksN     |
| 73 | 72 | imp 445 |
. . . 4
 
 
 WWalksN    substr
       WWalksN    |
| 74 | | eqeq2 2633 |
. . . . . 6
  substr         substr      
 substr        substr          |
| 75 | | fveq2 6191 |
. . . . . . . 8
  substr       lastS  
lastS   substr          |
| 76 | 75 | preq1d 4274 |
. . . . . . 7
  substr        lastS    lastS     lastS   substr         lastS      |
| 77 | 76 | eleq1d 2686 |
. . . . . 6
  substr         lastS    lastS     lastS   substr         lastS       |
| 78 | 74, 77 | anbi12d 747 |
. . . . 5
  substr          substr        lastS   
lastS       substr        substr        lastS   substr         lastS        |
| 79 | 78 | adantl 482 |
. . . 4
      WWalksN  
 substr           substr      
 lastS    lastS    
  substr      
 substr      
 lastS   substr         lastS        |
| 80 | 73, 79 | rspcedv 3313 |
. . 3
 
 
 WWalksN      substr        substr      
 lastS   substr         lastS    
  WWalksN
    substr      
 lastS    lastS        |
| 81 | 1, 71, 80 | mp2and 715 |
. 2
 
 
 WWalksN   
 WWalksN     substr      
 lastS    lastS       |
| 82 | 81 | ex 450 |
1

    WWalksN 
  WWalksN
    substr      
 lastS    lastS        |