Step | Hyp | Ref
| Expression |
1 | | ccatcl 13359 |
. . . 4
  Word
Word   ++  Word   |
2 | | swrdcl 13419 |
. . . 4
  ++  Word   ++  substr                   Word
  |
3 | | wrdf 13310 |
. . . 4
   ++  substr                   Word
  ++  substr                      ..^     ++  substr                         |
4 | | ffn 6045 |
. . . 4
   ++  substr                      ..^     ++  substr                         ++  substr                    ..^     ++  substr                       |
5 | 1, 2, 3, 4 | 4syl 19 |
. . 3
  Word
Word    ++  substr                    ..^     ++  substr                       |
6 | | lencl 13324 |
. . . . . . . . . 10
 Word       |
7 | 6 | adantr 481 |
. . . . . . . . 9
  Word
Word        |
8 | | nn0uz 11722 |
. . . . . . . . 9
     |
9 | 7, 8 | syl6eleq 2711 |
. . . . . . . 8
  Word
Word            |
10 | 7 | nn0zd 11480 |
. . . . . . . . . 10
  Word
Word        |
11 | | uzid 11702 |
. . . . . . . . . 10
    
              |
12 | 10, 11 | syl 17 |
. . . . . . . . 9
  Word
Word                |
13 | | lencl 13324 |
. . . . . . . . . 10
 Word       |
14 | 13 | adantl 482 |
. . . . . . . . 9
  Word
Word        |
15 | | uzaddcl 11744 |
. . . . . . . . 9
                                       |
16 | 12, 14, 15 | syl2anc 693 |
. . . . . . . 8
  Word
Word                      |
17 | | elfzuzb 12336 |
. . . . . . . 8
                  
                              |
18 | 9, 16, 17 | sylanbrc 698 |
. . . . . . 7
  Word
Word                      |
19 | 7, 14 | nn0addcld 11355 |
. . . . . . . . . 10
  Word
Word              |
20 | 19, 8 | syl6eleq 2711 |
. . . . . . . . 9
  Word
Word                  |
21 | 19 | nn0zd 11480 |
. . . . . . . . . 10
  Word
Word              |
22 | | uzid 11702 |
. . . . . . . . . 10
          
                          |
23 | 21, 22 | syl 17 |
. . . . . . . . 9
  Word
Word                            |
24 | | elfzuzb 12336 |
. . . . . . . . 9
                        
                                          |
25 | 20, 23, 24 | sylanbrc 698 |
. . . . . . . 8
  Word
Word                            |
26 | | ccatlen 13360 |
. . . . . . . . 9
  Word
Word      ++               |
27 | 26 | oveq2d 6666 |
. . . . . . . 8
  Word
Word         ++                    |
28 | 25, 27 | eleqtrrd 2704 |
. . . . . . 7
  Word
Word                   ++      |
29 | | swrdlen 13423 |
. . . . . . 7
   ++  Word                                    ++          ++  substr                                      |
30 | 1, 18, 28, 29 | syl3anc 1326 |
. . . . . 6
  Word
Word       ++  substr                                      |
31 | 7 | nn0cnd 11353 |
. . . . . . 7
  Word
Word        |
32 | 14 | nn0cnd 11353 |
. . . . . . 7
  Word
Word        |
33 | 31, 32 | pncan2d 10394 |
. . . . . 6
  Word
Word                        |
34 | 30, 33 | eqtrd 2656 |
. . . . 5
  Word
Word       ++  substr                          |
35 | 34 | oveq2d 6666 |
. . . 4
  Word
Word   ..^     ++  substr                      ..^       |
36 | 35 | fneq2d 5982 |
. . 3
  Word
Word     ++  substr                    ..^     ++  substr                    
  ++  substr                    ..^        |
37 | 5, 36 | mpbid 222 |
. 2
  Word
Word    ++  substr                    ..^       |
38 | | wrdf 13310 |
. . . 4
 Word    ..^         |
39 | 38 | adantl 482 |
. . 3
  Word
Word     ..^         |
40 | | ffn 6045 |
. . 3
    ..^        ..^       |
41 | 39, 40 | syl 17 |
. 2
  Word
Word   ..^       |
42 | 1 | adantr 481 |
. . . 4
   Word
Word   ..^       ++  Word   |
43 | 18 | adantr 481 |
. . . 4
   Word
Word   ..^                          |
44 | 28 | adantr 481 |
. . . 4
   Word
Word   ..^                       ++      |
45 | 33 | oveq2d 6666 |
. . . . . 6
  Word
Word   ..^                  ..^       |
46 | 45 | eleq2d 2687 |
. . . . 5
  Word
Word    ..^                  ..^        |
47 | 46 | biimpar 502 |
. . . 4
   Word
Word   ..^       ..^                   |
48 | | swrdfv 13424 |
. . . 4
    ++  Word
                                   ++      ..^                     ++  substr                        ++             |
49 | 42, 43, 44, 47, 48 | syl31anc 1329 |
. . 3
   Word
Word   ..^         ++  substr                        ++             |
50 | | ccatval3 13363 |
. . . 4
  Word
Word  ..^        ++                 |
51 | 50 | 3expa 1265 |
. . 3
   Word
Word   ..^        ++                 |
52 | 49, 51 | eqtrd 2656 |
. 2
   Word
Word   ..^         ++  substr                            |
53 | 37, 41, 52 | eqfnfvd 6314 |
1
  Word
Word    ++  substr                     |