| Step | Hyp | Ref
| Expression |
| 1 | | wwlksnextbij0.d |
. 2
 Word         substr      
 lastS    lastS       |
| 2 | | 3anass 1042 |
. . . . 5
        
substr        lastS    lastS              substr        lastS   
lastS        |
| 3 | 2 | bianass 842 |
. . . 4
  Word        
substr        lastS    lastS     
  Word
         substr      
 lastS    lastS        |
| 4 | | wwlksnextbij0.v |
. . . . . . . . . . 11
Vtx   |
| 5 | 4 | wwlknbp 26733 |
. . . . . . . . . 10
  WWalksN 

Word    |
| 6 | | simpl 473 |
. . . . . . . . . . . . . 14
    Word          substr        lastS   
lastS         |
| 7 | | simpl 473 |
. . . . . . . . . . . . . . . 16
  Word       
Word   |
| 8 | | nn0re 11301 |
. . . . . . . . . . . . . . . . . . . 20

  |
| 9 | | 2re 11090 |
. . . . . . . . . . . . . . . . . . . . 21
 |
| 10 | 9 | a1i 11 |
. . . . . . . . . . . . . . . . . . . 20

  |
| 11 | | nn0ge0 11318 |
. . . . . . . . . . . . . . . . . . . 20

  |
| 12 | | 2pos 11112 |
. . . . . . . . . . . . . . . . . . . . 21
 |
| 13 | 12 | a1i 11 |
. . . . . . . . . . . . . . . . . . . 20

  |
| 14 | 8, 10, 11, 13 | addgegt0d 10601 |
. . . . . . . . . . . . . . . . . . 19

    |
| 15 | 14 | adantr 481 |
. . . . . . . . . . . . . . . . . 18
  
Word         
   |
| 16 | | breq2 4657 |
. . . . . . . . . . . . . . . . . . 19
       
    
    |
| 17 | 16 | ad2antll 765 |
. . . . . . . . . . . . . . . . . 18
  
Word                   |
| 18 | 15, 17 | mpbird 247 |
. . . . . . . . . . . . . . . . 17
  
Word               |
| 19 | | hashgt0n0 13156 |
. . . . . . . . . . . . . . . . 17
  Word        |
| 20 | 7, 18, 19 | syl2an2 875 |
. . . . . . . . . . . . . . . 16
  
Word           |
| 21 | | lswcl 13355 |
. . . . . . . . . . . . . . . 16
  Word  lastS     |
| 22 | 7, 20, 21 | syl2an2 875 |
. . . . . . . . . . . . . . 15
  
Word         lastS
    |
| 23 | 22 | adantrr 753 |
. . . . . . . . . . . . . 14
    Word          substr        lastS   
lastS       lastS     |
| 24 | | swrdcl 13419 |
. . . . . . . . . . . . . . . . . . . . 21
 Word  substr      
Word   |
| 25 | | eleq1 2689 |
. . . . . . . . . . . . . . . . . . . . 21
  substr        Word  substr      
Word    |
| 26 | 24, 25 | syl5ibr 236 |
. . . . . . . . . . . . . . . . . . . 20
  substr        Word Word    |
| 27 | 26 | eqcoms 2630 |
. . . . . . . . . . . . . . . . . . 19
  substr      
 Word Word    |
| 28 | 27 | adantr 481 |
. . . . . . . . . . . . . . . . . 18
   substr      
 lastS    lastS      Word
Word    |
| 29 | 28 | com12 32 |
. . . . . . . . . . . . . . . . 17
 Word    substr      
 lastS    lastS     Word    |
| 30 | 29 | adantr 481 |
. . . . . . . . . . . . . . . 16
  Word           substr        lastS   
lastS     Word    |
| 31 | 30 | imp 445 |
. . . . . . . . . . . . . . 15
   Word          substr        lastS   
lastS     
Word   |
| 32 | 31 | adantl 482 |
. . . . . . . . . . . . . 14
    Word          substr        lastS   
lastS       Word   |
| 33 | | oveq1 6657 |
. . . . . . . . . . . . . . . . . 18
  substr        ++   lastS     
  substr       ++
  lastS        |
| 34 | 33 | eqcoms 2630 |
. . . . . . . . . . . . . . . . 17
  substr      
 ++   lastS     
  substr       ++
  lastS        |
| 35 | 34 | adantr 481 |
. . . . . . . . . . . . . . . 16
   substr      
 lastS    lastS      ++   lastS        substr       ++   lastS        |
| 36 | 35 | ad2antll 765 |
. . . . . . . . . . . . . . 15
    Word          substr        lastS   
lastS        ++   lastS        substr       ++   lastS        |
| 37 | | oveq1 6657 |
. . . . . . . . . . . . . . . . . . . . . 22
                   |
| 38 | 37 | adantl 482 |
. . . . . . . . . . . . . . . . . . . . 21
  Word                    |
| 39 | | nn0cn 11302 |
. . . . . . . . . . . . . . . . . . . . . . 23

  |
| 40 | | 2cnd 11093 |
. . . . . . . . . . . . . . . . . . . . . . 23

  |
| 41 | | 1cnd 10056 |
. . . . . . . . . . . . . . . . . . . . . . 23

  |
| 42 | 39, 40, 41 | addsubassd 10412 |
. . . . . . . . . . . . . . . . . . . . . 22

          |
| 43 | | 2m1e1 11135 |
. . . . . . . . . . . . . . . . . . . . . . . 24
   |
| 44 | 43 | a1i 11 |
. . . . . . . . . . . . . . . . . . . . . . 23

    |
| 45 | 44 | oveq2d 6666 |
. . . . . . . . . . . . . . . . . . . . . 22

        |
| 46 | 42, 45 | eqtrd 2656 |
. . . . . . . . . . . . . . . . . . . . 21

        |
| 47 | 38, 46 | sylan9eqr 2678 |
. . . . . . . . . . . . . . . . . . . 20
  
Word                   |
| 48 | 47 | opeq2d 4409 |
. . . . . . . . . . . . . . . . . . 19
  
Word                 
       |
| 49 | 48 | oveq2d 6666 |
. . . . . . . . . . . . . . . . . 18
  
Word          substr            substr         |
| 50 | 49 | oveq1d 6665 |
. . . . . . . . . . . . . . . . 17
  
Word           substr           ++   lastS        substr       ++   lastS        |
| 51 | | swrdccatwrd 13468 |
. . . . . . . . . . . . . . . . . 18
  Word    substr
          ++
  lastS     
  |
| 52 | 7, 20, 51 | syl2an2 875 |
. . . . . . . . . . . . . . . . 17
  
Word           substr           ++   lastS        |
| 53 | 50, 52 | eqtr3d 2658 |
. . . . . . . . . . . . . . . 16
  
Word           substr       ++   lastS        |
| 54 | 53 | adantrr 753 |
. . . . . . . . . . . . . . 15
    Word          substr        lastS   
lastS         substr
      ++   lastS     
  |
| 55 | 36, 54 | eqtr2d 2657 |
. . . . . . . . . . . . . 14
    Word          substr        lastS   
lastS        ++   lastS        |
| 56 | | simprrr 805 |
. . . . . . . . . . . . . 14
    Word          substr        lastS   
lastS        lastS    lastS      |
| 57 | | wwlksnextbij0.e |
. . . . . . . . . . . . . . 15
Edg   |
| 58 | 4, 57 | wwlksnextbi 26789 |
. . . . . . . . . . . . . 14
   lastS    
Word  ++   lastS       lastS    lastS   
 
    WWalksN
  WWalksN     |
| 59 | 6, 23, 32, 55, 56, 58 | syl23anc 1333 |
. . . . . . . . . . . . 13
    Word          substr        lastS   
lastS           WWalksN 

WWalksN     |
| 60 | 59 | exbiri 652 |
. . . . . . . . . . . 12

   Word          substr        lastS   
lastS     
  WWalksN
    WWalksN      |
| 61 | 60 | com23 86 |
. . . . . . . . . . 11

  WWalksN 
   Word          substr        lastS   
lastS     
   WWalksN
     |
| 62 | 61 | 3ad2ant2 1083 |
. . . . . . . . . 10
 
Word  
 WWalksN 
   Word          substr        lastS   
lastS     
   WWalksN
     |
| 63 | 5, 62 | mpcom 38 |
. . . . . . . . 9
  WWalksN 
   Word          substr        lastS   
lastS     
   WWalksN
    |
| 64 | 63 | expcomd 454 |
. . . . . . . 8
  WWalksN 
   substr
       lastS    lastS    
  Word
      
 
 WWalksN      |
| 65 | 64 | imp 445 |
. . . . . . 7
   WWalksN    substr
       lastS    lastS        Word           WWalksN     |
| 66 | 4, 57 | wwlknp 26734 |
. . . . . . . . . . . 12
    WWalksN 
 Word           ..^                    |
| 67 | 39, 41, 41 | addassd 10062 |
. . . . . . . . . . . . . . . . . . . 20

          |
| 68 | | 1p1e2 11134 |
. . . . . . . . . . . . . . . . . . . . . 22
   |
| 69 | 68 | a1i 11 |
. . . . . . . . . . . . . . . . . . . . 21

    |
| 70 | 69 | oveq2d 6666 |
. . . . . . . . . . . . . . . . . . . 20

        |
| 71 | 67, 70 | eqtrd 2656 |
. . . . . . . . . . . . . . . . . . 19

        |
| 72 | 71 | eqeq2d 2632 |
. . . . . . . . . . . . . . . . . 18

        
         |
| 73 | 72 | biimpd 219 |
. . . . . . . . . . . . . . . . 17

                  |
| 74 | 73 | adantr 481 |
. . . . . . . . . . . . . . . 16
 
Word                    |
| 75 | 74 | com12 32 |
. . . . . . . . . . . . . . 15
           Word           |
| 76 | 75 | adantl 482 |
. . . . . . . . . . . . . 14
  Word           
Word 
         |
| 77 | | simpl 473 |
. . . . . . . . . . . . . 14
  Word         
Word   |
| 78 | 76, 77 | jctild 566 |
. . . . . . . . . . . . 13
  Word           
Word 
 Word           |
| 79 | 78 | 3adant3 1081 |
. . . . . . . . . . . 12
  Word         
 ..^                    Word   Word           |
| 80 | 66, 79 | syl 17 |
. . . . . . . . . . 11
    WWalksN 
 
Word   Word
          |
| 81 | 80 | com12 32 |
. . . . . . . . . 10
 
Word      WWalksN   Word
          |
| 82 | 81 | 3adant1 1079 |
. . . . . . . . 9
 
Word      WWalksN   Word
          |
| 83 | 5, 82 | syl 17 |
. . . . . . . 8
  WWalksN 
    WWalksN
  Word           |
| 84 | 83 | adantr 481 |
. . . . . . 7
   WWalksN    substr
       lastS    lastS          WWalksN   Word
          |
| 85 | 65, 84 | impbid 202 |
. . . . . 6
   WWalksN    substr
       lastS    lastS        Word           WWalksN     |
| 86 | 85 | ex 450 |
. . . . 5
  WWalksN 
   substr
       lastS    lastS    
  Word
      
   WWalksN
     |
| 87 | 86 | pm5.32rd 672 |
. . . 4
  WWalksN 
   Word          substr        lastS   
lastS          WWalksN
   substr      
 lastS    lastS         |
| 88 | 3, 87 | syl5bb 272 |
. . 3
  WWalksN 
  Word
       
substr        lastS    lastS     
    WWalksN
   substr      
 lastS    lastS         |
| 89 | 88 | rabbidva2 3186 |
. 2
  WWalksN 
 Word         substr      
 lastS    lastS          WWalksN    substr      
 lastS    lastS        |
| 90 | 1, 89 | syl5eq 2668 |
1
  WWalksN 

   WWalksN    substr      
 lastS    lastS        |