Proof of Theorem splfv2a
| Step | Hyp | Ref
| Expression |
| 1 | | spllen.s |
. . . 4
 Word   |
| 2 | | spllen.f |
. . . 4
       |
| 3 | | spllen.t |
. . . 4
           |
| 4 | | spllen.r |
. . . 4
 Word   |
| 5 | | splval 13502 |
. . . 4
  Word 
   
        Word    splice
  
     substr     ++  ++  substr            |
| 6 | 1, 2, 3, 4, 5 | syl13anc 1328 |
. . 3
  splice   
     substr     ++  ++  substr            |
| 7 | | elfznn0 12433 |
. . . . . . 7
       |
| 8 | 2, 7 | syl 17 |
. . . . . 6
   |
| 9 | 8 | nn0cnd 11353 |
. . . . 5
   |
| 10 | | splfv2a.x |
. . . . . . 7
  ..^       |
| 11 | | elfzoelz 12470 |
. . . . . . 7
  ..^    
  |
| 12 | 10, 11 | syl 17 |
. . . . . 6
   |
| 13 | 12 | zcnd 11483 |
. . . . 5
   |
| 14 | 9, 13 | addcomd 10238 |
. . . 4
       |
| 15 | | nn0uz 11722 |
. . . . . . . . 9
     |
| 16 | 8, 15 | syl6eleq 2711 |
. . . . . . . 8
       |
| 17 | | eluzfz1 12348 |
. . . . . . . 8
    
      |
| 18 | 16, 17 | syl 17 |
. . . . . . 7
       |
| 19 | | elfzuz3 12339 |
. . . . . . . . . 10
                   |
| 20 | 3, 19 | syl 17 |
. . . . . . . . 9
           |
| 21 | | elfzuz3 12339 |
. . . . . . . . . 10
           |
| 22 | 2, 21 | syl 17 |
. . . . . . . . 9
       |
| 23 | | uztrn 11704 |
. . . . . . . . 9
              
          |
| 24 | 20, 22, 23 | syl2anc 693 |
. . . . . . . 8
           |
| 25 | | elfzuzb 12336 |
. . . . . . . 8
        
                |
| 26 | 16, 24, 25 | sylanbrc 698 |
. . . . . . 7
           |
| 27 | | swrdlen 13423 |
. . . . . . 7
  Word
   
             substr          |
| 28 | 1, 18, 26, 27 | syl3anc 1326 |
. . . . . 6
     substr          |
| 29 | 9 | subid1d 10381 |
. . . . . 6
     |
| 30 | 28, 29 | eqtrd 2656 |
. . . . 5
     substr        |
| 31 | 30 | oveq2d 6666 |
. . . 4
      substr           |
| 32 | 14, 31 | eqtr4d 2659 |
. . 3
        substr         |
| 33 | 6, 32 | fveq12d 6197 |
. 2
   splice   
           substr     ++  ++  substr            
    substr          |
| 34 | | swrdcl 13419 |
. . . . 5
 Word  substr     Word   |
| 35 | 1, 34 | syl 17 |
. . . 4
  substr     Word   |
| 36 | | ccatcl 13359 |
. . . 4
   substr     Word
Word    substr     ++  Word   |
| 37 | 35, 4, 36 | syl2anc 693 |
. . 3
   substr     ++  Word   |
| 38 | | swrdcl 13419 |
. . . 4
 Word  substr         Word   |
| 39 | 1, 38 | syl 17 |
. . 3
  substr        
Word   |
| 40 | | 0nn0 11307 |
. . . . . . . 8
 |
| 41 | | nn0addcl 11328 |
. . . . . . . 8
 
     |
| 42 | 40, 8, 41 | sylancr 695 |
. . . . . . 7
     |
| 43 | | fzoss1 12495 |
. . . . . . . 8
      
   ..^      
 ..^         |
| 44 | 43, 15 | eleq2s 2719 |
. . . . . . 7
  
   ..^      
 ..^         |
| 45 | 42, 44 | syl 17 |
. . . . . 6
    ..^        ..^         |
| 46 | | ccatlen 13360 |
. . . . . . . . 9
   substr     Word
Word       substr
    ++        substr             |
| 47 | 35, 4, 46 | syl2anc 693 |
. . . . . . . 8
      substr
    ++        substr             |
| 48 | 30 | oveq1d 6665 |
. . . . . . . 8
      substr                   |
| 49 | | wrdfin 13323 |
. . . . . . . . . . . 12
 Word   |
| 50 | 4, 49 | syl 17 |
. . . . . . . . . . 11
   |
| 51 | | hashcl 13147 |
. . . . . . . . . . 11
       |
| 52 | 50, 51 | syl 17 |
. . . . . . . . . 10
       |
| 53 | 52 | nn0cnd 11353 |
. . . . . . . . 9
       |
| 54 | 9, 53 | addcomd 10238 |
. . . . . . . 8
               |
| 55 | 47, 48, 54 | 3eqtrd 2660 |
. . . . . . 7
      substr
    ++           |
| 56 | 55 | oveq2d 6666 |
. . . . . 6
  ..^     substr     ++     ..^         |
| 57 | 45, 56 | sseqtr4d 3642 |
. . . . 5
    ..^        ..^     substr
    ++      |
| 58 | 8 | nn0zd 11480 |
. . . . . 6
   |
| 59 | | fzoaddel 12520 |
. . . . . 6
   ..^      
    ..^         |
| 60 | 10, 58, 59 | syl2anc 693 |
. . . . 5
      ..^         |
| 61 | 57, 60 | sseldd 3604 |
. . . 4
    ..^     substr
    ++      |
| 62 | 31, 61 | eqeltrd 2701 |
. . 3
      substr        ..^     substr
    ++      |
| 63 | | ccatval1 13361 |
. . 3
    substr     ++  Word  substr         Word 
    substr        ..^     substr     ++         substr     ++  ++  substr                 substr           substr     ++    
    substr          |
| 64 | 37, 39, 62, 63 | syl3anc 1326 |
. 2
     substr     ++  ++  substr            
    substr           substr     ++    
    substr          |
| 65 | | ccatval3 13363 |
. . 3
   substr     Word
Word
 ..^         substr     ++    
    substr              |
| 66 | 35, 4, 10, 65 | syl3anc 1326 |
. 2
    substr     ++    
    substr              |
| 67 | 33, 64, 66 | 3eqtrd 2660 |
1
   splice   
             |