| Step | Hyp | Ref
| Expression |
| 1 | | hofpropd.1 |
. . 3
 
f   
f     |
| 2 | 1 | homfeqbas 16356 |
. . . . 5
           |
| 3 | 2 | sqxpeqd 5141 |
. . . 4
                       |
| 4 | 3 | adantr 481 |
. . . 4
 
                                 |
| 5 | | eqid 2622 |
. . . . . 6
         |
| 6 | | eqid 2622 |
. . . . . 6
       |
| 7 | | eqid 2622 |
. . . . . 6
       |
| 8 | 1 | adantr 481 |
. . . . . 6
 
          
             f
   f
    |
| 9 | | xp1st 7198 |
. . . . . . 7
                     |
| 10 | 9 | ad2antll 765 |
. . . . . 6
 
          
                      |
| 11 | | xp1st 7198 |
. . . . . . 7
                     |
| 12 | 11 | ad2antrl 764 |
. . . . . 6
 
          
                      |
| 13 | 5, 6, 7, 8, 10, 12 | homfeqval 16357 |
. . . . 5
 
          
                                            |
| 14 | | xp2nd 7199 |
. . . . . . . 8
                     |
| 15 | 14 | ad2antrl 764 |
. . . . . . 7
 
          
                      |
| 16 | | xp2nd 7199 |
. . . . . . . 8
                     |
| 17 | 16 | ad2antll 765 |
. . . . . . 7
 
          
                      |
| 18 | 5, 6, 7, 8, 15, 17 | homfeqval 16357 |
. . . . . 6
 
          
                                            |
| 19 | 18 | adantr 481 |
. . . . 5
                                                                          |
| 20 | 5, 6, 7, 8, 12, 15 | homfeqval 16357 |
. . . . . . . . 9
 
          
                                            |
| 21 | | df-ov 6653 |
. . . . . . . . 9
                                  |
| 22 | | df-ov 6653 |
. . . . . . . . 9
                                  |
| 23 | 20, 21, 22 | 3eqtr3g 2679 |
. . . . . . . 8
 
          
                                                  |
| 24 | | 1st2nd2 7205 |
. . . . . . . . . 10
                        |
| 25 | 24 | ad2antrl 764 |
. . . . . . . . 9
 
          
                         |
| 26 | 25 | fveq2d 6195 |
. . . . . . . 8
 
          
                                       |
| 27 | 25 | fveq2d 6195 |
. . . . . . . 8
 
          
                                       |
| 28 | 23, 26, 27 | 3eqtr4d 2666 |
. . . . . . 7
 
          
                            |
| 29 | 28 | adantr 481 |
. . . . . 6
                                         
                                 |
| 30 | | eqid 2622 |
. . . . . . . 8
comp  comp   |
| 31 | | eqid 2622 |
. . . . . . . 8
comp  comp   |
| 32 | 8 | ad2antrr 762 |
. . . . . . . 8
    
                                     
                        
 f    f     |
| 33 | | hofpropd.2 |
. . . . . . . . 9
 compf  compf    |
| 34 | 33 | ad3antrrr 766 |
. . . . . . . 8
    
                                     
                        
compf  compf    |
| 35 | 10 | ad2antrr 762 |
. . . . . . . 8
    
                                     
                        
          |
| 36 | 12 | ad2antrr 762 |
. . . . . . . 8
    
                                     
                        
          |
| 37 | 17 | ad2antrr 762 |
. . . . . . . 8
    
                                     
                        
          |
| 38 | | simplrl 800 |
. . . . . . . 8
    
                                     
                        
                 |
| 39 | 25 | ad2antrr 762 |
. . . . . . . . . . 11
    
                                     
                        
             |
| 40 | 39 | oveq1d 6665 |
. . . . . . . . . 10
    
                                     
                        
  comp                     comp          |
| 41 | 40 | oveqd 6667 |
. . . . . . . . 9
    
                                     
                        
    comp                         comp            |
| 42 | | hofpropd.c |
. . . . . . . . . . 11
   |
| 43 | 42 | ad3antrrr 766 |
. . . . . . . . . 10
    
                                     
                        
  |
| 44 | 15 | ad2antrr 762 |
. . . . . . . . . 10
    
                                     
                        
          |
| 45 | 26 | adantr 481 |
. . . . . . . . . . . . 13
                                         
                                            |
| 46 | 45, 21 | syl6eqr 2674 |
. . . . . . . . . . . 12
                                         
                                         |
| 47 | 46 | eleq2d 2687 |
. . . . . . . . . . 11
                                         
                                           |
| 48 | 47 | biimpa 501 |
. . . . . . . . . 10
    
                                     
                        
                 |
| 49 | | simplrr 801 |
. . . . . . . . . 10
    
                                     
                        
                 |
| 50 | 5, 6, 30, 43, 36, 44, 37, 48, 49 | catcocl 16346 |
. . . . . . . . 9
    
                                     
                        
               comp                           |
| 51 | 41, 50 | eqeltrd 2701 |
. . . . . . . 8
    
                                     
                        
    comp                           |
| 52 | 5, 6, 30, 31, 32, 34, 35, 36, 37, 38, 51 | comfeqval 16368 |
. . . . . . 7
    
                                     
                        
     comp                        comp               comp                        comp            |
| 53 | 5, 6, 30, 31, 32, 34, 36, 44, 37, 48, 49 | comfeqval 16368 |
. . . . . . . . 9
    
                                     
                        
               comp                         comp            |
| 54 | 39 | oveq1d 6665 |
. . . . . . . . . 10
    
                                     
                        
  comp                     comp          |
| 55 | 54 | oveqd 6667 |
. . . . . . . . 9
    
                                     
                        
    comp                         comp            |
| 56 | 53, 41, 55 | 3eqtr4d 2666 |
. . . . . . . 8
    
                                     
                        
    comp              comp            |
| 57 | 56 | oveq1d 6665 |
. . . . . . 7
    
                                     
                        
     comp                        comp               comp                        comp            |
| 58 | 52, 57 | eqtrd 2656 |
. . . . . 6
    
                                     
                        
     comp                        comp               comp                        comp            |
| 59 | 29, 58 | mpteq12dva 4732 |
. . . . 5
                                         
                              comp                        comp                        comp                        comp             |
| 60 | 13, 19, 59 | mpt2eq123dva 6716 |
. . . 4
 
          
                                                         comp                        comp                                                         comp                        comp              |
| 61 | 3, 4, 60 | mpt2eq123dva 6716 |
. . 3
                                                                    comp                        comp                                                                                comp                        comp               |
| 62 | 1, 61 | opeq12d 4410 |
. 2
  
f                                                                       comp                        comp                f
                                                                      comp                        comp                |
| 63 | | eqid 2622 |
. . 3
HomF  HomF   |
| 64 | 63, 42, 5, 6, 30 | hofval 16892 |
. 2
 HomF   
f                                                                       comp                        comp                |
| 65 | | eqid 2622 |
. . 3
HomF  HomF   |
| 66 | | hofpropd.d |
. . 3
   |
| 67 | | eqid 2622 |
. . 3
         |
| 68 | 65, 66, 67, 7, 31 | hofval 16892 |
. 2
 HomF   
f                                                                       comp                        comp                |
| 69 | 62, 64, 68 | 3eqtr4d 2666 |
1
 HomF  HomF    |