| Step | Hyp | Ref
| Expression |
| 1 | | sseqval.2 |
. . . 4
 Word   |
| 2 | | wrdf 13310 |
. . . 4
 Word    ..^         |
| 3 | 1, 2 | syl 17 |
. . 3
    ..^         |
| 4 | | vex 3203 |
. . . . . . . . 9
 |
| 5 | 4 | a1i 11 |
. . . . . . . 8
 

      |
| 6 | | fvex 6201 |
. . . . . . . . 9
           |
| 7 | | df-lsw 13300 |
. . . . . . . . 9
lastS              |
| 8 | 6, 7 | dmmpti 6023 |
. . . . . . . 8
lastS  |
| 9 | 5, 8 | syl6eleqr 2712 |
. . . . . . 7
 

    lastS  |
| 10 | | eldifsn 4317 |
. . . . . . . . 9
    

   |
| 11 | | sseqval.3 |
. . . . . . . . . . . 12
Word                |
| 12 | | inss1 3833 |
. . . . . . . . . . . 12
Word               Word  |
| 13 | 11, 12 | eqsstri 3635 |
. . . . . . . . . . 11
Word  |
| 14 | 13 | sseli 3599 |
. . . . . . . . . 10
 Word   |
| 15 | | lswcl 13355 |
. . . . . . . . . 10
  Word  lastS     |
| 16 | 14, 15 | sylan 488 |
. . . . . . . . 9
   lastS     |
| 17 | 10, 16 | sylbi 207 |
. . . . . . . 8
     lastS     |
| 18 | 17 | adantl 482 |
. . . . . . 7
 

    lastS     |
| 19 | 9, 18 | jca 554 |
. . . . . 6
 

     lastS lastS      |
| 20 | 19 | ralrimiva 2966 |
. . . . 5
        lastS lastS      |
| 21 | 6, 7 | fnmpti 6022 |
. . . . . 6
lastS  |
| 22 | | fnfun 5988 |
. . . . . 6
lastS
lastS  |
| 23 | | ffvresb 6394 |
. . . . . 6
 lastS  lastS                     lastS lastS       |
| 24 | 21, 22, 23 | mp2b 10 |
. . . . 5
 lastS             
      
lastS lastS      |
| 25 | 20, 24 | sylibr 224 |
. . . 4
 lastS                |
| 26 | | eqid 2622 |
. . . . 5
                 |
| 27 | | lencl 13324 |
. . . . . . 7
 Word       |
| 28 | 27 | nn0zd 11480 |
. . . . . 6
 Word       |
| 29 | 1, 28 | syl 17 |
. . . . 5
       |
| 30 | | ovex 6678 |
. . . . . . 7
 ++         
 |
| 31 | | simpr 477 |
. . . . . . . . 9
 
                   |
| 32 | 1, 27 | syl 17 |
. . . . . . . . . . 11
       |
| 33 | 32 | adantr 481 |
. . . . . . . . . 10
 
               |
| 34 | | elnn0uz 11725 |
. . . . . . . . . 10
               |
| 35 | 33, 34 | sylib 208 |
. . . . . . . . 9
 
                   |
| 36 | | uztrn 11704 |
. . . . . . . . 9
                         |
| 37 | 31, 35, 36 | syl2anc 693 |
. . . . . . . 8
 
               |
| 38 | | nn0uz 11722 |
. . . . . . . 8
     |
| 39 | 37, 38 | syl6eleqr 2712 |
. . . . . . 7
 
           |
| 40 | | fvconst2g 6467 |
. . . . . . 7
   ++               ++                ++            |
| 41 | 30, 39, 40 | sylancr 695 |
. . . . . 6
 
             ++                ++            |
| 42 | | sseqval.4 |
. . . . . . . . . . . . 13
       |
| 43 | | sseqval.1 |
. . . . . . . . . . . . . 14
   |
| 44 | 43, 1, 11, 42 | sseqmw 30453 |
. . . . . . . . . . . . 13
   |
| 45 | 42, 44 | ffvelrnd 6360 |
. . . . . . . . . . . 12
       |
| 46 | 45 | s1cld 13383 |
. . . . . . . . . . 11
         Word
  |
| 47 | | ccatcl 13359 |
. . . . . . . . . . 11
  Word         Word   ++          Word   |
| 48 | 1, 46, 47 | syl2anc 693 |
. . . . . . . . . 10
  ++          Word   |
| 49 | 30 | a1i 11 |
. . . . . . . . . . 11
  ++            |
| 50 | | ccatws1len 13398 |
. . . . . . . . . . . . 13
  Word          ++                   |
| 51 | 1, 45, 50 | syl2anc 693 |
. . . . . . . . . . . 12
     ++                   |
| 52 | | uzid 11702 |
. . . . . . . . . . . . 13
    
              |
| 53 | | peano2uz 11741 |
. . . . . . . . . . . . 13
                             |
| 54 | 29, 52, 53 | 3syl 18 |
. . . . . . . . . . . 12
                 |
| 55 | 51, 54 | eqeltrd 2701 |
. . . . . . . . . . 11
     ++                     |
| 56 | | hashf 13125 |
. . . . . . . . . . . 12
        |
| 57 | | ffn 6045 |
. . . . . . . . . . . 12
          |
| 58 | | elpreima 6337 |
. . . . . . . . . . . 12

  ++                      
  ++              ++                       |
| 59 | 56, 57, 58 | mp2b 10 |
. . . . . . . . . . 11
  ++                      
  ++              ++                      |
| 60 | 49, 55, 59 | sylanbrc 698 |
. . . . . . . . . 10
  ++                         |
| 61 | 48, 60 | elind 3798 |
. . . . . . . . 9
  ++          Word
                |
| 62 | 61, 11 | syl6eleqr 2712 |
. . . . . . . 8
  ++            |
| 63 | 62 | adantr 481 |
. . . . . . 7
 
          ++            |
| 64 | 1 | adantr 481 |
. . . . . . . 8
 
        
Word   |
| 65 | 42 | adantr 481 |
. . . . . . . . 9
 
               |
| 66 | 44 | adantr 481 |
. . . . . . . . 9
 
        
  |
| 67 | 65, 66 | ffvelrnd 6360 |
. . . . . . . 8
 
               |
| 68 | | ccatws1n0 13409 |
. . . . . . . 8
  Word       ++            |
| 69 | 64, 67, 68 | syl2anc 693 |
. . . . . . 7
 
          ++            |
| 70 | | eldifsn 4317 |
. . . . . . 7
  ++                ++         
 ++
            |
| 71 | 63, 69, 70 | sylanbrc 698 |
. . . . . 6
 
          ++                |
| 72 | 41, 71 | eqeltrd 2701 |
. . . . 5
 
             ++                     |
| 73 | | eqidd 2623 |
. . . . . . 7
 
              ++              ++             |
| 74 | | simprl 794 |
. . . . . . . 8
              
    |
| 75 | 74 | fveq2d 6195 |
. . . . . . . . 9
              
            |
| 76 | 75 | s1eqd 13381 |
. . . . . . . 8
              
                    |
| 77 | 74, 76 | oveq12d 6668 |
. . . . . . 7
              
   ++           ++            |
| 78 | | vex 3203 |
. . . . . . . 8
 |
| 79 | 78 | a1i 11 |
. . . . . . 7
 
             |
| 80 | | vex 3203 |
. . . . . . . 8
 |
| 81 | 80 | a1i 11 |
. . . . . . 7
 
             |
| 82 | | ovex 6678 |
. . . . . . . 8
 ++         
 |
| 83 | 82 | a1i 11 |
. . . . . . 7
 
            ++            |
| 84 | 73, 77, 79, 81, 83 | ovmpt2d 6788 |
. . . . . 6
 
                ++              ++            |
| 85 | | eldifi 3732 |
. . . . . . . . . . . 12
       |
| 86 | 85 | ad2antrl 764 |
. . . . . . . . . . 11
 
             |
| 87 | 13, 86 | sseldi 3601 |
. . . . . . . . . 10
 
           Word   |
| 88 | 42 | adantr 481 |
. . . . . . . . . . . 12
 
                 |
| 89 | 88, 86 | ffvelrnd 6360 |
. . . . . . . . . . 11
 
                 |
| 90 | 89 | s1cld 13383 |
. . . . . . . . . 10
 
                   Word
  |
| 91 | | ccatcl 13359 |
. . . . . . . . . 10
  Word         Word   ++          Word   |
| 92 | 87, 90, 91 | syl2anc 693 |
. . . . . . . . 9
 
            ++          Word   |
| 93 | | ccatws1len 13398 |
. . . . . . . . . . . 12
  Word          ++                   |
| 94 | 87, 89, 93 | syl2anc 693 |
. . . . . . . . . . 11
 
               ++                   |
| 95 | 86, 11 | syl6eleq 2711 |
. . . . . . . . . . . . . . 15
 
           Word
                |
| 96 | | elin 3796 |
. . . . . . . . . . . . . . . 16
 Word              
 Word                 |
| 97 | 96 | simprbi 480 |
. . . . . . . . . . . . . . 15
 Word                              |
| 98 | 95, 97 | syl 17 |
. . . . . . . . . . . . . 14
 
                          |
| 99 | | elpreima 6337 |
. . . . . . . . . . . . . . 15

             
                 |
| 100 | 56, 57, 99 | mp2b 10 |
. . . . . . . . . . . . . 14
             
                |
| 101 | 98, 100 | sylib 208 |
. . . . . . . . . . . . 13
 
           
               |
| 102 | 101 | simprd 479 |
. . . . . . . . . . . 12
 
                         |
| 103 | | peano2uz 11741 |
. . . . . . . . . . . 12
                             |
| 104 | 102, 103 | syl 17 |
. . . . . . . . . . 11
 
                           |
| 105 | 94, 104 | eqeltrd 2701 |
. . . . . . . . . 10
 
               ++                     |
| 106 | | elpreima 6337 |
. . . . . . . . . . 11

  ++                      
  ++              ++                       |
| 107 | 56, 57, 106 | mp2b 10 |
. . . . . . . . . 10
  ++                      
  ++              ++                      |
| 108 | 83, 105, 107 | sylanbrc 698 |
. . . . . . . . 9
 
            ++                         |
| 109 | 92, 108 | elind 3798 |
. . . . . . . 8
 
            ++          Word                 |
| 110 | 109, 11 | syl6eleqr 2712 |
. . . . . . 7
 
            ++            |
| 111 | | ccatws1n0 13409 |
. . . . . . . 8
  Word       ++            |
| 112 | 87, 89, 111 | syl2anc 693 |
. . . . . . 7
 
            ++            |
| 113 | | eldifsn 4317 |
. . . . . . 7
  ++                ++         
 ++
            |
| 114 | 110, 112,
113 | sylanbrc 698 |
. . . . . 6
 
            ++                |
| 115 | 84, 114 | eqeltrd 2701 |
. . . . 5
 
                ++                   |
| 116 | 26, 29, 72, 115 | seqf 12822 |
. . . 4
           ++               ++                               |
| 117 | | fco2 6059 |
. . . 4
  lastS                        ++               ++                              lastS
          ++               ++                            |
| 118 | 25, 116, 117 | syl2anc 693 |
. . 3
 lastS
        
 ++
              ++                            |
| 119 | | fzouzdisj 12504 |
. . . 4
  ..^               |
| 120 | 119 | a1i 11 |
. . 3
   ..^    
           |
| 121 | | fun 6066 |
. . 3
      ..^       lastS           ++               ++                             ..^              
 lastS           ++               ++                   ..^                    |
| 122 | 3, 118, 120, 121 | syl21anc 1325 |
. 2
  lastS           ++               ++                   ..^                    |
| 123 | 43, 1, 11, 42 | sseqval 30450 |
. . 3
  seqstr  lastS           ++               ++                 |
| 124 | | fzouzsplit 12503 |
. . . . . 6
               ..^                |
| 125 | 34, 124 | sylbi 207 |
. . . . 5
    
      ..^                |
| 126 | 1, 27, 125 | 3syl 18 |
. . . 4
       ..^                |
| 127 | 38, 126 | syl5eq 2668 |
. . 3
   ..^                |
| 128 | | unidm 3756 |
. . . . 5
   |
| 129 | 128 | a1i 11 |
. . . 4
     |
| 130 | 129 | eqcomd 2628 |
. . 3
     |
| 131 | 123, 127,
130 | feq123d 6034 |
. 2
   seqstr    

lastS         
 ++
              ++                   ..^                     |
| 132 | 122, 131 | mpbird 247 |
1
  seqstr       |