Proof of Theorem ccatopth
| Step | Hyp | Ref
| Expression |
| 1 | | oveq1 6657 |
. . . 4
  ++   ++    ++  substr           ++  substr           |
| 2 | | swrdccat1 13457 |
. . . . . 6
  Word
Word    ++  substr           |
| 3 | 2 | 3ad2ant1 1082 |
. . . . 5
   Word
Word   Word Word 
           ++  substr           |
| 4 | | simp3 1063 |
. . . . . . . 8
   Word
Word   Word Word 
                   |
| 5 | 4 | opeq2d 4409 |
. . . . . . 7
   Word
Word   Word Word 
                 
       |
| 6 | 5 | oveq2d 6666 |
. . . . . 6
   Word
Word   Word Word 
           ++  substr           ++  substr  
        |
| 7 | | swrdccat1 13457 |
. . . . . . 7
  Word
Word    ++  substr           |
| 8 | 7 | 3ad2ant2 1083 |
. . . . . 6
   Word
Word   Word Word 
           ++  substr           |
| 9 | 6, 8 | eqtrd 2656 |
. . . . 5
   Word
Word   Word Word 
           ++  substr           |
| 10 | 3, 9 | eqeq12d 2637 |
. . . 4
   Word
Word   Word Word 
            ++  substr           ++  substr            |
| 11 | 1, 10 | syl5ib 234 |
. . 3
   Word
Word   Word Word 
           ++   ++     |
| 12 | | simpr 477 |
. . . . . 6
    Word Word 
 Word Word            ++   ++    ++   ++    |
| 13 | | simpl3 1066 |
. . . . . . 7
    Word Word 
 Word Word            ++   ++             |
| 14 | 12 | fveq2d 6195 |
. . . . . . . 8
    Word Word 
 Word Word            ++   ++       ++       ++     |
| 15 | | simpl1 1064 |
. . . . . . . . 9
    Word Word 
 Word Word            ++   ++    Word Word    |
| 16 | | ccatlen 13360 |
. . . . . . . . 9
  Word
Word      ++               |
| 17 | 15, 16 | syl 17 |
. . . . . . . 8
    Word Word 
 Word Word            ++   ++       ++               |
| 18 | | simpl2 1065 |
. . . . . . . . 9
    Word Word 
 Word Word            ++   ++    Word Word    |
| 19 | | ccatlen 13360 |
. . . . . . . . 9
  Word
Word      ++               |
| 20 | 18, 19 | syl 17 |
. . . . . . . 8
    Word Word 
 Word Word            ++   ++       ++               |
| 21 | 14, 17, 20 | 3eqtr3d 2664 |
. . . . . . 7
    Word Word 
 Word Word            ++   ++                         |
| 22 | 13, 21 | opeq12d 4410 |
. . . . . 6
    Word Word 
 Word Word            ++   ++                                       |
| 23 | 12, 22 | oveq12d 6668 |
. . . . 5
    Word Word 
 Word Word            ++   ++     ++  substr                     ++  substr                     |
| 24 | | swrdccat2 13458 |
. . . . . 6
  Word
Word    ++  substr                     |
| 25 | 15, 24 | syl 17 |
. . . . 5
    Word Word 
 Word Word            ++   ++     ++  substr                     |
| 26 | | swrdccat2 13458 |
. . . . . 6
  Word
Word    ++  substr                     |
| 27 | 18, 26 | syl 17 |
. . . . 5
    Word Word 
 Word Word            ++   ++     ++  substr                     |
| 28 | 23, 25, 27 | 3eqtr3d 2664 |
. . . 4
    Word Word 
 Word Word            ++   ++     |
| 29 | 28 | ex 450 |
. . 3
   Word
Word   Word Word 
           ++   ++     |
| 30 | 11, 29 | jcad 555 |
. 2
   Word
Word   Word Word 
           ++   ++  
    |
| 31 | | oveq12 6659 |
. 2
 
  ++   ++    |
| 32 | 30, 31 | impbid1 215 |
1
   Word
Word   Word Word 
           ++   ++ 

    |