| Step | Hyp | Ref
| Expression |
| 1 | | simpl 109 |
. . . . . 6
  Word 
   
   
   ♯     Word   |
| 2 | | elfzelz 10147 |
. . . . . . . 8
       |
| 3 | 2 | 3ad2ant1 1021 |
. . . . . . 7
     
   
   ♯   
  |
| 4 | 3 | adantl 277 |
. . . . . 6
  Word 
   
   
   ♯       |
| 5 | | elfzel2 10145 |
. . . . . . . 8
       |
| 6 | 5 | 3ad2ant1 1021 |
. . . . . . 7
     
   
   ♯   
  |
| 7 | 6 | adantl 277 |
. . . . . 6
  Word 
   
   
   ♯       |
| 8 | | swrdclg 11103 |
. . . . . 6
  Word
  substr     Word   |
| 9 | 1, 4, 7, 8 | syl3anc 1250 |
. . . . 5
  Word 
   
   
   ♯      substr     Word   |
| 10 | | elfzel2 10145 |
. . . . . . . 8
       |
| 11 | 10 | 3ad2ant2 1022 |
. . . . . . 7
     
   
   ♯   
  |
| 12 | 11 | adantl 277 |
. . . . . 6
  Word 
   
   
   ♯       |
| 13 | | swrdclg 11103 |
. . . . . 6
  Word
  substr     Word   |
| 14 | 1, 7, 12, 13 | syl3anc 1250 |
. . . . 5
  Word 
   
   
   ♯      substr     Word   |
| 15 | | ccatcl 11049 |
. . . . 5
   substr     Word  substr     Word 
  substr     ++  substr      Word   |
| 16 | 9, 14, 15 | syl2anc 411 |
. . . 4
  Word 
   
   
   ♯       substr     ++  substr      Word   |
| 17 | | wrdfn 11009 |
. . . 4
   substr     ++  substr      Word   substr     ++  substr       ..^ ♯   substr     ++  substr          |
| 18 | 16, 17 | syl 14 |
. . 3
  Word 
   
   
   ♯       substr     ++  substr       ..^ ♯   substr
    ++  substr          |
| 19 | | ccatlen 11051 |
. . . . . . 7
   substr     Word  substr     Word 
♯   substr
    ++  substr        ♯  substr  
   ♯  substr         |
| 20 | 9, 14, 19 | syl2anc 411 |
. . . . . 6
  Word 
   
   
   ♯     ♯   substr     ++  substr        ♯  substr      ♯  substr         |
| 21 | | simpr1 1006 |
. . . . . . . 8
  Word 
   
   
   ♯           |
| 22 | | simpr2 1007 |
. . . . . . . . 9
  Word 
   
   
   ♯           |
| 23 | | simpr3 1008 |
. . . . . . . . 9
  Word 
   
   
   ♯        ♯     |
| 24 | | fzass4 10184 |
. . . . . . . . . . 11
     ♯      ♯            ♯      |
| 25 | 24 | biimpri 133 |
. . . . . . . . . 10
     
   ♯        ♯      ♯      |
| 26 | 25 | simpld 112 |
. . . . . . . . 9
     
   ♯   
   ♯     |
| 27 | 22, 23, 26 | syl2anc 411 |
. . . . . . . 8
  Word 
   
   
   ♯        ♯     |
| 28 | | swrdlen 11105 |
. . . . . . . 8
  Word
   
   ♯    ♯  substr          |
| 29 | 1, 21, 27, 28 | syl3anc 1250 |
. . . . . . 7
  Word 
   
   
   ♯     ♯  substr  
       |
| 30 | | swrdlen 11105 |
. . . . . . . 8
  Word
   
   ♯    ♯  substr          |
| 31 | 30 | 3adant3r1 1215 |
. . . . . . 7
  Word 
   
   
   ♯     ♯  substr  
       |
| 32 | 29, 31 | oveq12d 5962 |
. . . . . 6
  Word 
   
   
   ♯      ♯  substr      ♯  substr               |
| 33 | 22 | elfzelzd 10148 |
. . . . . . . 8
  Word 
   
   
   ♯       |
| 34 | 33 | zcnd 9496 |
. . . . . . 7
  Word 
   
   
   ♯       |
| 35 | 21 | elfzelzd 10148 |
. . . . . . . 8
  Word 
   
   
   ♯       |
| 36 | 35 | zcnd 9496 |
. . . . . . 7
  Word 
   
   
   ♯       |
| 37 | 23 | elfzelzd 10148 |
. . . . . . . 8
  Word 
   
   
   ♯       |
| 38 | 37 | zcnd 9496 |
. . . . . . 7
  Word 
   
   
   ♯       |
| 39 | 34, 36, 38 | npncan3d 8419 |
. . . . . 6
  Word 
   
   
   ♯               |
| 40 | 20, 32, 39 | 3eqtrd 2242 |
. . . . 5
  Word 
   
   
   ♯     ♯   substr     ++  substr           |
| 41 | 40 | oveq2d 5960 |
. . . 4
  Word 
   
   
   ♯      ..^ ♯   substr     ++  substr         ..^     |
| 42 | 41 | fneq2d 5365 |
. . 3
  Word 
   
   
   ♯        substr     ++  substr       ..^ ♯   substr
    ++  substr       
  substr     ++  substr       ..^      |
| 43 | 18, 42 | mpbid 147 |
. 2
  Word 
   
   
   ♯       substr     ++  substr       ..^     |
| 44 | | swrdclg 11103 |
. . . . 5
  Word
  substr     Word   |
| 45 | 1, 4, 12, 44 | syl3anc 1250 |
. . . 4
  Word 
   
   
   ♯      substr     Word   |
| 46 | | wrdfn 11009 |
. . . 4
  substr     Word  substr
     ..^ ♯  substr  
      |
| 47 | 45, 46 | syl 14 |
. . 3
  Word 
   
   
   ♯      substr      ..^ ♯  substr  
      |
| 48 | | fzass4 10184 |
. . . . . . . . 9
     
    
    
       |
| 49 | 48 | biimpri 133 |
. . . . . . . 8
     
         
       |
| 50 | 49 | simpld 112 |
. . . . . . 7
     
           |
| 51 | 21, 22, 50 | syl2anc 411 |
. . . . . 6
  Word 
   
   
   ♯           |
| 52 | | swrdlen 11105 |
. . . . . 6
  Word
   
   ♯    ♯  substr          |
| 53 | 1, 51, 23, 52 | syl3anc 1250 |
. . . . 5
  Word 
   
   
   ♯     ♯  substr  
       |
| 54 | 53 | oveq2d 5960 |
. . . 4
  Word 
   
   
   ♯      ..^ ♯  substr        ..^     |
| 55 | 54 | fneq2d 5365 |
. . 3
  Word 
   
   
   ♯       substr      ..^ ♯  substr        substr
     ..^      |
| 56 | 47, 55 | mpbid 147 |
. 2
  Word 
   
   
   ♯      substr      ..^     |
| 57 | 33, 35 | zsubcld 9500 |
. . . . . 6
  Word 
   
   
   ♯         |
| 58 | 57 | anim1ci 341 |
. . . . 5
   Word             ♯      ..^      ..^        |
| 59 | | fzospliti 10300 |
. . . . 5
   ..^   
    ..^      ..^      |
| 60 | 58, 59 | syl 14 |
. . . 4
   Word             ♯      ..^      ..^      ..^      |
| 61 | 9 | adantr 276 |
. . . . . . 7
   Word             ♯      ..^     substr     Word   |
| 62 | 14 | adantr 276 |
. . . . . . 7
   Word             ♯      ..^     substr     Word   |
| 63 | 29 | oveq2d 5960 |
. . . . . . . . 9
  Word 
   
   
   ♯      ..^ ♯  substr        ..^     |
| 64 | 63 | eleq2d 2275 |
. . . . . . . 8
  Word 
   
   
   ♯       ..^ ♯  substr      
 ..^      |
| 65 | 64 | biimpar 297 |
. . . . . . 7
   Word             ♯      ..^     ..^ ♯  substr         |
| 66 | | ccatval1 11053 |
. . . . . . 7
   substr     Word  substr     Word
 ..^ ♯  substr  
        substr     ++  substr           substr          |
| 67 | 61, 62, 65, 66 | syl3anc 1250 |
. . . . . 6
   Word             ♯      ..^       substr     ++  substr           substr          |
| 68 | | simpll 527 |
. . . . . . 7
   Word             ♯      ..^    Word   |
| 69 | | simplr1 1042 |
. . . . . . 7
   Word             ♯      ..^          |
| 70 | 27 | adantr 276 |
. . . . . . 7
   Word             ♯      ..^       ♯     |
| 71 | | simpr 110 |
. . . . . . 7
   Word             ♯      ..^     ..^     |
| 72 | | swrdfv 11106 |
. . . . . . 7
   Word
   
   ♯   
 ..^      substr                |
| 73 | 68, 69, 70, 71, 72 | syl31anc 1253 |
. . . . . 6
   Word             ♯      ..^      substr                |
| 74 | 67, 73 | eqtrd 2238 |
. . . . 5
   Word             ♯      ..^       substr     ++  substr                 |
| 75 | 9 | adantr 276 |
. . . . . . 7
   Word             ♯        ..^     substr     Word   |
| 76 | 14 | adantr 276 |
. . . . . . 7
   Word             ♯        ..^     substr     Word   |
| 77 | 32, 39 | eqtrd 2238 |
. . . . . . . . . 10
  Word 
   
   
   ♯      ♯  substr      ♯  substr           |
| 78 | 29, 77 | oveq12d 5962 |
. . . . . . . . 9
  Word 
   
   
   ♯      ♯  substr      ..^ ♯  substr      ♯  substr  
        ..^     |
| 79 | 78 | eleq2d 2275 |
. . . . . . . 8
  Word 
   
   
   ♯       ♯  substr      ..^ ♯  substr      ♯  substr  
    
   ..^      |
| 80 | 79 | biimpar 297 |
. . . . . . 7
   Word             ♯        ..^     ♯  substr  
   ..^ ♯  substr      ♯  substr          |
| 81 | | ccatval2 11054 |
. . . . . . 7
   substr     Word  substr     Word
 ♯  substr      ..^ ♯  substr  
   ♯  substr        
   substr
    ++  substr           substr        ♯  substr          |
| 82 | 75, 76, 80, 81 | syl3anc 1250 |
. . . . . 6
   Word             ♯        ..^       substr     ++  substr           substr        ♯  substr          |
| 83 | | simpll 527 |
. . . . . . 7
   Word             ♯        ..^    Word   |
| 84 | | simplr2 1043 |
. . . . . . 7
   Word             ♯        ..^          |
| 85 | | simplr3 1044 |
. . . . . . 7
   Word             ♯        ..^       ♯     |
| 86 | 29 | oveq2d 5960 |
. . . . . . . . 9
  Word 
   
   
   ♯      ♯  substr        
    |
| 87 | 86 | adantr 276 |
. . . . . . . 8
   Word             ♯        ..^     ♯  substr        
    |
| 88 | 39 | oveq2d 5960 |
. . . . . . . . . . 11
  Word 
   
   
   ♯        ..^          ..^     |
| 89 | 88 | eleq2d 2275 |
. . . . . . . . . 10
  Word 
   
   
   ♯         ..^      
   ..^      |
| 90 | 89 | biimpar 297 |
. . . . . . . . 9
   Word             ♯        ..^       ..^         |
| 91 | 37, 33 | zsubcld 9500 |
. . . . . . . . . 10
  Word 
   
   
   ♯         |
| 92 | 91 | adantr 276 |
. . . . . . . . 9
   Word             ♯        ..^        |
| 93 | | fzosubel3 10325 |
. . . . . . . . 9
     ..^       
       ..^     |
| 94 | 90, 92, 93 | syl2anc 411 |
. . . . . . . 8
   Word             ♯        ..^     
   ..^     |
| 95 | 87, 94 | eqeltrd 2282 |
. . . . . . 7
   Word             ♯        ..^     ♯  substr        ..^     |
| 96 | | swrdfv 11106 |
. . . . . . 7
   Word
   
   ♯    
♯  substr        ..^      substr
       ♯  substr             ♯  substr           |
| 97 | 83, 84, 85, 95, 96 | syl31anc 1253 |
. . . . . 6
   Word             ♯        ..^      substr        ♯  substr             ♯  substr           |
| 98 | 86 | oveq1d 5959 |
. . . . . . . . 9
  Word 
   
   
   ♯       ♯  substr          
     |
| 99 | 98 | adantr 276 |
. . . . . . . 8
   Word             ♯        ..^      ♯  substr          
     |
| 100 | | elfzoelz 10269 |
. . . . . . . . . . 11
    ..^  
  |
| 101 | 100 | zcnd 9496 |
. . . . . . . . . 10
    ..^  
  |
| 102 | 101 | adantl 277 |
. . . . . . . . 9
   Word             ♯        ..^      |
| 103 | 34, 36 | subcld 8383 |
. . . . . . . . . 10
  Word 
   
   
   ♯         |
| 104 | 103 | adantr 276 |
. . . . . . . . 9
   Word             ♯        ..^        |
| 105 | 34 | adantr 276 |
. . . . . . . . 9
   Word             ♯        ..^      |
| 106 | 102, 104,
105 | subadd23d 8405 |
. . . . . . . 8
   Word             ♯        ..^                  |
| 107 | 34, 36 | nncand 8388 |
. . . . . . . . . 10
  Word 
   
   
   ♯      
    |
| 108 | 107 | oveq2d 5960 |
. . . . . . . . 9
  Word 
   
   
   ♯      

       |
| 109 | 108 | adantr 276 |
. . . . . . . 8
   Word             ♯        ..^     

       |
| 110 | 99, 106, 109 | 3eqtrd 2242 |
. . . . . . 7
   Word             ♯        ..^      ♯  substr            |
| 111 | 110 | fveq2d 5580 |
. . . . . 6
   Word             ♯        ..^         ♯  substr            
    |
| 112 | 82, 97, 111 | 3eqtrd 2242 |
. . . . 5
   Word             ♯        ..^       substr     ++  substr                 |
| 113 | 74, 112 | jaodan 799 |
. . . 4
   Word             ♯       ..^      ..^    
   substr
    ++  substr            
    |
| 114 | 60, 113 | syldan 282 |
. . 3
   Word             ♯      ..^       substr     ++  substr                 |
| 115 | | simpll 527 |
. . . 4
   Word             ♯      ..^    Word   |
| 116 | 51 | adantr 276 |
. . . 4
   Word             ♯      ..^          |
| 117 | | simplr3 1044 |
. . . 4
   Word             ♯      ..^       ♯     |
| 118 | | simpr 110 |
. . . 4
   Word             ♯      ..^     ..^     |
| 119 | | swrdfv 11106 |
. . . 4
   Word
   
   ♯   
 ..^      substr                |
| 120 | 115, 116,
117, 118, 119 | syl31anc 1253 |
. . 3
   Word             ♯      ..^      substr                |
| 121 | 114, 120 | eqtr4d 2241 |
. 2
   Word             ♯      ..^       substr     ++  substr           substr          |
| 122 | 43, 56, 121 | eqfnfvd 5680 |
1
  Word 
   
   
   ♯       substr     ++  substr       substr       |