Proof of Theorem splfv1
| 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 | 6 | fveq1d 6193 |
. 2
   splice   
         substr     ++  ++  substr               |
| 8 | | swrdcl 13419 |
. . . . 5
 Word  substr     Word   |
| 9 | 1, 8 | syl 17 |
. . . 4
  substr     Word   |
| 10 | | ccatcl 13359 |
. . . 4
   substr     Word
Word    substr     ++  Word   |
| 11 | 9, 4, 10 | syl2anc 693 |
. . 3
   substr     ++  Word   |
| 12 | | swrdcl 13419 |
. . . 4
 Word  substr         Word   |
| 13 | 1, 12 | syl 17 |
. . 3
  substr        
Word   |
| 14 | | elfzelz 12342 |
. . . . . . . 8
       |
| 15 | | uzid 11702 |
. . . . . . . 8
       |
| 16 | 2, 14, 15 | 3syl 18 |
. . . . . . 7
       |
| 17 | | wrdfin 13323 |
. . . . . . . 8
 Word   |
| 18 | | hashcl 13147 |
. . . . . . . 8
       |
| 19 | 4, 17, 18 | 3syl 18 |
. . . . . . 7
       |
| 20 | | uzaddcl 11744 |
. . . . . . 7
           
           |
| 21 | 16, 19, 20 | syl2anc 693 |
. . . . . 6
             |
| 22 | | fzoss2 12496 |
. . . . . 6
            ..^  ..^         |
| 23 | 21, 22 | syl 17 |
. . . . 5
  ..^  ..^         |
| 24 | | splfv1.x |
. . . . 5
  ..^   |
| 25 | 23, 24 | sseldd 3604 |
. . . 4
  ..^         |
| 26 | | ccatlen 13360 |
. . . . . . 7
   substr     Word
Word       substr
    ++        substr             |
| 27 | 9, 4, 26 | syl2anc 693 |
. . . . . 6
      substr
    ++        substr             |
| 28 | | elfzuz 12338 |
. . . . . . . . . 10
           |
| 29 | | eluzfz1 12348 |
. . . . . . . . . 10
    
      |
| 30 | 2, 28, 29 | 3syl 18 |
. . . . . . . . 9
       |
| 31 | | fzass4 12379 |
. . . . . . . . . . . 12
                       
           |
| 32 | 31 | bicomi 214 |
. . . . . . . . . . 11
     
        
                    |
| 33 | 32 | simplbi 476 |
. . . . . . . . . 10
     
        
          |
| 34 | 2, 3, 33 | syl2anc 693 |
. . . . . . . . 9
           |
| 35 | | swrdlen 13423 |
. . . . . . . . 9
  Word
   
             substr          |
| 36 | 1, 30, 34, 35 | syl3anc 1326 |
. . . . . . . 8
     substr          |
| 37 | 2, 14 | syl 17 |
. . . . . . . . . 10
   |
| 38 | 37 | zcnd 11483 |
. . . . . . . . 9
   |
| 39 | 38 | subid1d 10381 |
. . . . . . . 8
     |
| 40 | 36, 39 | eqtrd 2656 |
. . . . . . 7
     substr        |
| 41 | 40 | oveq1d 6665 |
. . . . . 6
      substr                   |
| 42 | 27, 41 | eqtrd 2656 |
. . . . 5
      substr
    ++           |
| 43 | 42 | oveq2d 6666 |
. . . 4
  ..^     substr     ++     ..^         |
| 44 | 25, 43 | eleqtrrd 2704 |
. . 3
  ..^     substr
    ++      |
| 45 | | ccatval1 13361 |
. . 3
    substr     ++  Word  substr         Word
 ..^     substr
    ++         substr     ++  ++  substr                substr     ++       |
| 46 | 11, 13, 44, 45 | syl3anc 1326 |
. 2
     substr     ++  ++  substr                substr     ++       |
| 47 | 40 | oveq2d 6666 |
. . . . 5
  ..^    substr        ..^   |
| 48 | 24, 47 | eleqtrrd 2704 |
. . . 4
  ..^    substr         |
| 49 | | ccatval1 13361 |
. . . 4
   substr     Word
Word
 ..^    substr           substr     ++       substr          |
| 50 | 9, 4, 48, 49 | syl3anc 1326 |
. . 3
    substr     ++       substr          |
| 51 | 39 | oveq2d 6666 |
. . . . 5
  ..^    ..^   |
| 52 | 24, 51 | eleqtrrd 2704 |
. . . 4
  ..^     |
| 53 | | swrdfv 13424 |
. . . 4
   Word
   
        
 ..^      substr                |
| 54 | 1, 30, 34, 52, 53 | syl31anc 1329 |
. . 3
   substr                |
| 55 | | elfzoelz 12470 |
. . . . . . 7
  ..^
  |
| 56 | 55 | zcnd 11483 |
. . . . . 6
  ..^
  |
| 57 | 24, 56 | syl 17 |
. . . . 5
   |
| 58 | 57 | addid1d 10236 |
. . . 4
     |
| 59 | 58 | fveq2d 6195 |
. . 3
    
        |
| 60 | 50, 54, 59 | 3eqtrd 2660 |
. 2
    substr     ++           |
| 61 | 7, 46, 60 | 3eqtrd 2660 |
1
   splice   
           |