Proof of Theorem idfisf
| Step | Hyp | Ref
| Expression |
| 1 | | fvex 4689 |
. . . . 5
dom   |
| 2 | 1 | dmex 4208 |
. . . 4
dom   |
| 3 | | resiexg 4253 |
. . . 4
 dom 
dom     |
| 4 | 2, 3 | ax-mp 7 |
. . 3
dom    |
| 5 | | eqid 1884 |
. . . . . . . . . . . . 13
dom  dom   |
| 6 | | eqid 1884 |
. . . . . . . . . . . . 13
id  id   |
| 7 | | eqid 1884 |
. . . . . . . . . . . . 13
id  id   |
| 8 | 5, 6, 7 | jdmo 15125 |
. . . . . . . . . . . 12
  Cat
id    id     dom    |
| 9 | | fvresi 4819 |
. . . . . . . . . . . 12
  id     dom 

dom      id       id       |
| 10 | 8, 9 | syl 12 |
. . . . . . . . . . 11
  Cat
id    dom      id       id       |
| 11 | | fveq2 4681 |
. . . . . . . . . . . . . . 15
  id      id       |
| 12 | 11 | eqeq2d 1895 |
. . . . . . . . . . . . . 14
  
dom      id       id      dom      id       id        |
| 13 | 12 | rcla4ev 2381 |
. . . . . . . . . . . . 13
  id   dom      id       id       id   
dom      id       id       |
| 14 | 13 | ex 402 |
. . . . . . . . . . . 12
 id    dom      id       id      id    dom      id       id        |
| 15 | 14 | adantl 424 |
. . . . . . . . . . 11
  Cat
id    
dom      id       id      id    dom      id       id        |
| 16 | 10, 15 | mpd 29 |
. . . . . . . . . 10
  Cat
id    id    dom      id       id       |
| 17 | 16 | ex 402 |
. . . . . . . . 9
 Cat
 id  
id   
dom      id       id        |
| 18 | 17 | r19.21aiv 2175 |
. . . . . . . 8
 Cat

id    id    dom      id       id       |
| 19 | | simpl 346 |
. . . . . . . . . . . . . 14
  Cat
dom   Cat  |
| 20 | | eqid 1884 |
. . . . . . . . . . . . . . 15
dom  dom   |
| 21 | 5, 6, 20 | dmo 15123 |
. . . . . . . . . . . . . 14
  Cat
dom    dom     id    |
| 22 | 19, 21 | jca 310 |
. . . . . . . . . . . . 13
  Cat
dom    Cat  dom     id     |
| 23 | 5, 6, 7 | jdmo 15125 |
. . . . . . . . . . . . 13
  Cat  dom     id    id     dom      dom    |
| 24 | | fvresi 4819 |
. . . . . . . . . . . . 13
  id     dom      dom 

dom      id     dom        id     dom        |
| 25 | 22, 23, 24 | 3syl 24 |
. . . . . . . . . . . 12
  Cat
dom    dom      id     dom        id     dom        |
| 26 | | fvresi 4819 |
. . . . . . . . . . . . . . . 16

dom   dom        |
| 27 | 26 | eqcomd 1889 |
. . . . . . . . . . . . . . 15

dom  
dom        |
| 28 | 27 | fveq2d 4685 |
. . . . . . . . . . . . . 14

dom   dom      dom     dom         |
| 29 | 28 | fveq2d 4685 |
. . . . . . . . . . . . 13

dom   id     dom       id     dom    
dom          |
| 30 | 29 | adantl 424 |
. . . . . . . . . . . 12
  Cat
dom    id     dom       id     dom    
dom          |
| 31 | 25, 30 | eqtrd 1925 |
. . . . . . . . . . 11
  Cat
dom    dom      id     dom        id     dom     dom          |
| 32 | 31 | ex 402 |
. . . . . . . . . 10
 Cat

dom   dom      id     dom        id     dom     dom           |
| 33 | 32 | r19.21aiv 2175 |
. . . . . . . . 9
 Cat

dom   
dom      id     dom        id     dom    
dom          |
| 34 | | eqid 1884 |
. . . . . . . . . . . . . . 15
cod  cod   |
| 35 | 5, 6, 34 | cdmo 15124 |
. . . . . . . . . . . . . 14
  Cat
dom    cod     id    |
| 36 | 19, 35 | jca 310 |
. . . . . . . . . . . . 13
  Cat
dom    Cat  cod     id     |
| 37 | 5, 6, 7 | jdmo 15125 |
. . . . . . . . . . . . 13
  Cat  cod     id    id     cod      dom    |
| 38 | | fvresi 4819 |
. . . . . . . . . . . . 13
  id     cod      dom 

dom      id     cod        id     cod        |
| 39 | 36, 37, 38 | 3syl 24 |
. . . . . . . . . . . 12
  Cat
dom    dom      id     cod        id     cod        |
| 40 | 27 | fveq2d 4685 |
. . . . . . . . . . . . . 14

dom   cod      cod     dom         |
| 41 | 40 | fveq2d 4685 |
. . . . . . . . . . . . 13

dom   id     cod       id     cod    
dom          |
| 42 | 41 | adantl 424 |
. . . . . . . . . . . 12
  Cat
dom    id     cod       id     cod    
dom          |
| 43 | 39, 42 | eqtrd 1925 |
. . . . . . . . . . 11
  Cat
dom    dom      id     cod        id     cod     dom          |
| 44 | 43 | ex 402 |
. . . . . . . . . 10
 Cat

dom   dom      id     cod        id     cod     dom           |
| 45 | 44 | r19.21aiv 2175 |
. . . . . . . . 9
 Cat

dom   
dom      id     cod        id     cod    
dom          |
| 46 | 33, 45 | jca 310 |
. . . . . . . 8
 Cat
  dom    dom      id     dom        id     dom     dom        
dom   
dom      id     cod        id     cod    
dom           |
| 47 | | eqid 1884 |
. . . . . . . . . . . . . . . 16
o  o   |
| 48 | 5, 20, 34, 47 | cmpmorp 15126 |
. . . . . . . . . . . . . . 15
  Cat
dom 
dom     dom      cod       o    dom     |
| 49 | 48 | com12 14 |
. . . . . . . . . . . . . 14
  dom      cod       Cat
dom  dom     o    dom     |
| 50 | 49 | eqcoms 1887 |
. . . . . . . . . . . . 13
  cod      dom       Cat
dom  dom     o    dom     |
| 51 | 50 | com12 14 |
. . . . . . . . . . . 12
  Cat
dom 
dom     cod      dom       o    dom     |
| 52 | | fvresi 4819 |
. . . . . . . . . . . . . . 15
   o    dom 

dom       o       o      |
| 53 | | fvresi 4819 |
. . . . . . . . . . . . . . . . 17

dom   dom        |
| 54 | 26, 53 | opreqan12rd 4903 |
. . . . . . . . . . . . . . . 16
  dom  dom    
dom       o    dom         o      |
| 55 | 54 | eqcomd 1889 |
. . . . . . . . . . . . . . 15
  dom  dom     o     
dom       o    dom         |
| 56 | 52, 55 | sylan9eqr 1951 |
. . . . . . . . . . . . . 14
   dom 
dom     o    dom    dom       o       dom       o    dom         |
| 57 | 56 | ex 402 |
. . . . . . . . . . . . 13
  dom  dom      o    dom   dom       o       dom       o    dom          |
| 58 | 57 | 3adant1 894 |
. . . . . . . . . . . 12
  Cat
dom 
dom      o    dom 

dom       o      
dom       o   
dom          |
| 59 | 51, 58 | syld 30 |
. . . . . . . . . . 11
  Cat
dom 
dom     cod      dom      dom       o       dom       o    dom          |
| 60 | 59 | 3com23 1074 |
. . . . . . . . . 10
  Cat
dom 
dom     cod      dom      dom       o       dom       o    dom          |
| 61 | 60 | 3expib 1070 |
. . . . . . . . 9
 Cat
  dom  dom     cod      dom      dom       o       dom       o    dom           |
| 62 | 61 | r19.21aivv 2183 |
. . . . . . . 8
 Cat

dom    dom     cod      dom      dom       o       dom       o    dom          |
| 63 | 18, 46, 62 | 3jca 1050 |
. . . . . . 7
 Cat
  id    id   
dom      id       id       dom   
dom      id     dom        id     dom    
dom         dom    dom      id     cod        id     cod     dom         
dom   
dom     cod      dom      dom       o       dom       o    dom           |
| 64 | | f1oi 4671 |
. . . . . . . 8
dom     dom    dom   |
| 65 | | f1of 4635 |
. . . . . . . 8
 dom     dom    dom 
dom     dom    dom    |
| 66 | 64, 65 | ax-mp 7 |
. . . . . . 7
dom     dom    dom   |
| 67 | 63, 66 | jctil 316 |
. . . . . 6
 Cat
 dom     dom    dom 
 
id    id   
dom      id       id       dom   
dom      id     dom        id     dom    
dom         dom    dom      id     cod        id     cod     dom         
dom   
dom     cod      dom      dom       o       dom       o    dom            |
| 68 | 67 | 3ad2ant1 897 |
. . . . 5
  Cat Cat
dom   

dom     dom    dom 
 
id    id   
dom      id       id       dom   
dom      id     dom        id     dom    
dom         dom    dom      id     cod        id     cod     dom         
dom   
dom     cod      dom      dom       o       dom       o    dom            |
| 69 | 6, 5, 20, 34, 7, 47, 6, 5,
20, 34, 7, 47 | isfunb 15183 |
. . . . 5
  Cat Cat
dom   

dom   Func       dom     dom    dom 
 
id    id   
dom      id       id       dom   
dom      id     dom        id     dom    
dom         dom    dom      id     cod        id     cod     dom         
dom   
dom     cod      dom      dom       o       dom       o    dom             |
| 70 | 68, 69 | mpbird 213 |
. . . 4
  Cat Cat
dom   
dom   Func        |
| 71 | 70 | 3exp 1066 |
. . 3
 Cat
 Cat
 dom   dom   Func          |
| 72 | 4, 71 | mpii 56 |
. 2
 Cat
 Cat
dom   Func         |
| 73 | 72 | pm2.43i 78 |
1
 Cat
dom   Func        |