Proof of Theorem homgrf
| Step | Hyp | Ref
| Expression |
| 1 | | homgrf.1 |
. . . . . . . . . . . . 13
id   |
| 2 | | eqid 1884 |
. . . . . . . . . . . . 13
dom  dom   |
| 3 | | homgrf.2 |
. . . . . . . . . . . . 13
hom
   |
| 4 | 1, 2, 3 | ehm 15140 |
. . . . . . . . . . . 12
  Cat
        
dom     |
| 5 | 4 | 3adant3r3 1079 |
. . . . . . . . . . 11
  Cat    
      
dom     |
| 6 | 5 | com12 14 |
. . . . . . . . . 10

      
  Cat   
dom     |
| 7 | 6 | adantr 425 |
. . . . . . . . 9
        
          Cat 
  dom     |
| 8 | 7 | impcom 378 |
. . . . . . . 8
   Cat           
         dom    |
| 9 | 1, 2, 3 | ehm 15140 |
. . . . . . . . . . . 12
  Cat
        
dom     |
| 10 | 9 | 3adant3r1 1077 |
. . . . . . . . . . 11
  Cat    
      
dom     |
| 11 | 10 | com12 14 |
. . . . . . . . . 10

      
  Cat   
dom     |
| 12 | 11 | adantl 424 |
. . . . . . . . 9
        
          Cat 
  dom     |
| 13 | 12 | impcom 378 |
. . . . . . . 8
   Cat           
         dom    |
| 14 | | eqid 1884 |
. . . . . . . . . . . . . 14
dom  dom   |
| 15 | 1, 14, 3 | dehm 15141 |
. . . . . . . . . . . . 13
  Cat
          dom        |
| 16 | 15 | 3adant3r1 1077 |
. . . . . . . . . . . 12
  Cat    
      
 dom        |
| 17 | 16 | com12 14 |
. . . . . . . . . . 11

      
  Cat     dom        |
| 18 | 17 | adantl 424 |
. . . . . . . . . 10
        
          Cat 
   dom        |
| 19 | 18 | impcom 378 |
. . . . . . . . 9
   Cat           
          dom       |
| 20 | | eqid 1884 |
. . . . . . . . . . . . . . . . 17
cod  cod   |
| 21 | 1, 20, 3 | cehm 15142 |
. . . . . . . . . . . . . . . 16
  Cat
          cod        |
| 22 | 21 | imp 377 |
. . . . . . . . . . . . . . 15
   Cat

    
    cod       |
| 23 | 22 | eqcomd 1889 |
. . . . . . . . . . . . . 14
   Cat

    
    cod       |
| 24 | 23 | ex 402 |
. . . . . . . . . . . . 13
  Cat
        
 cod        |
| 25 | 24 | 3adant3r3 1079 |
. . . . . . . . . . . 12
  Cat    
      
 cod        |
| 26 | 25 | com12 14 |
. . . . . . . . . . 11

      
  Cat     cod        |
| 27 | 26 | adantr 425 |
. . . . . . . . . 10
        
          Cat 
   cod        |
| 28 | 27 | impcom 378 |
. . . . . . . . 9
   Cat           
          cod       |
| 29 | 19, 28 | eqtrd 1925 |
. . . . . . . 8
   Cat           
          dom      cod       |
| 30 | 8, 13, 29 | 3jca 1050 |
. . . . . . 7
   Cat           
          dom 
dom   dom      cod        |
| 31 | 30 | ex 402 |
. . . . . 6
  Cat            
         dom 
dom   dom      cod         |
| 32 | | homgrf.3 |
. . . . . . . . . 10
o   |
| 33 | 2, 14, 20, 32 | cmpmorp 15126 |
. . . . . . . . 9
  Cat
dom 
dom     dom      cod         dom     |
| 34 | 33 | 3exp 1066 |
. . . . . . . 8
 Cat

dom  
dom    dom      cod         dom       |
| 35 | 34 | 3impd 1082 |
. . . . . . 7
 Cat
  dom  dom   dom      cod          dom     |
| 36 | 35 | adantr 425 |
. . . . . 6
  Cat      dom  dom   dom      cod          dom     |
| 37 | 31, 36 | syld 30 |
. . . . 5
  Cat            
            dom     |
| 38 | 37 | imp 377 |
. . . 4
   Cat           
             dom    |
| 39 | | catded 15111 |
. . . . . . . 8
 Cat
Ded  |
| 40 | 39 | ad2antrr 440 |
. . . . . . 7
   Cat           
         Ded  |
| 41 | 40, 8, 13 | 3jca 1050 |
. . . . . 6
   Cat           
          Ded dom 
dom     |
| 42 | 21 | 3adant3r3 1079 |
. . . . . . . . . 10
  Cat    
      
 cod        |
| 43 | 42 | com12 14 |
. . . . . . . . 9

      
  Cat     cod        |
| 44 | 43 | adantr 425 |
. . . . . . . 8
        
          Cat 
   cod        |
| 45 | 44 | impcom 378 |
. . . . . . 7
   Cat           
          cod       |
| 46 | 19, 45 | eqtr4d 1928 |
. . . . . 6
   Cat           
          dom      cod       |
| 47 | 2, 14, 20, 32 | domcmpd 15093 |
. . . . . 6
  Ded
dom 
dom     dom      cod      dom          dom        |
| 48 | 41, 46, 47 | sylc 83 |
. . . . 5
   Cat           
          dom          dom       |
| 49 | 1, 14, 3 | dehm 15141 |
. . . . . . . . 9
  Cat
          dom        |
| 50 | 49 | 3adant3r3 1079 |
. . . . . . . 8
  Cat    
      
 dom        |
| 51 | 50 | com12 14 |
. . . . . . 7

      
  Cat     dom        |
| 52 | 51 | adantr 425 |
. . . . . 6
        
          Cat 
   dom        |
| 53 | 52 | impcom 378 |
. . . . 5
   Cat           
          dom       |
| 54 | 48, 53 | eqtrd 1925 |
. . . 4
   Cat           
          dom           |
| 55 | 2, 14, 20, 32 | codcmpd 15094 |
. . . . . 6
  Ded
dom 
dom     dom      cod      cod          cod        |
| 56 | 41, 46, 55 | sylc 83 |
. . . . 5
   Cat           
          cod          cod       |
| 57 | 1, 20, 3 | cehm 15142 |
. . . . . . . . 9
  Cat
          cod        |
| 58 | 57 | 3adant3r1 1077 |
. . . . . . . 8
  Cat    
      
 cod        |
| 59 | 58 | com12 14 |
. . . . . . 7

      
  Cat     cod        |
| 60 | 59 | adantl 424 |
. . . . . 6
        
          Cat 
   cod        |
| 61 | 60 | impcom 378 |
. . . . 5
   Cat           
          cod       |
| 62 | 56, 61 | eqtrd 1925 |
. . . 4
   Cat           
          cod           |
| 63 | 38, 54, 62 | 3jca 1050 |
. . 3
   Cat           
              dom 
 dom          cod            |
| 64 | 63 | ex 402 |
. 2
  Cat            
             dom 
 dom          cod             |
| 65 | 1, 2, 14, 20, 3 | ishomd 15139 |
. . 3
  Cat
                  dom   dom          cod             |
| 66 | 65 | 3adant3r2 1078 |
. 2
  Cat                     dom   dom          cod             |
| 67 | 64, 66 | sylibrd 221 |
1
  Cat            
                      |