| Step | Hyp | Ref
| Expression |
| 1 | | relres 5426 |
. 2
  Image
Singleton      |
| 2 | | vex 3203 |
. . . . . . 7
 |
| 3 | 2 | brres 5402 |
. . . . . 6
    Image
Singleton          Image Singleton       |
| 4 | 3 | simplbi 476 |
. . . . 5
    Image
Singleton     
    |
| 5 | | vex 3203 |
. . . . . . . 8
 |
| 6 | 5 | brres 5402 |
. . . . . . 7
    Image
Singleton          Image Singleton       |
| 7 | | ancom 466 |
. . . . . . . 8
   
 Image
Singleton       Image Singleton         |
| 8 | | funpartlem 32049 |
. . . . . . . . 9
  Image
Singleton   
            |
| 9 | 8 | anbi1i 731 |
. . . . . . . 8
   Image
Singleton      
                |
| 10 | 7, 9 | bitri 264 |
. . . . . . 7
   
 Image
Singleton                     |
| 11 | 6, 10 | bitri 264 |
. . . . . 6
    Image
Singleton                      |
| 12 | | df-br 4654 |
. . . . . . . . . . 11
  
  
  |
| 13 | | df-br 4654 |
. . . . . . . . . . 11
  
  
  |
| 14 | 12, 13 | anbi12i 733 |
. . . . . . . . . 10
      
          |
| 15 | | vex 3203 |
. . . . . . . . . . . 12
 |
| 16 | 15, 5 | elimasn 5490 |
. . . . . . . . . . 11
            |
| 17 | 15, 2 | elimasn 5490 |
. . . . . . . . . . 11
            |
| 18 | 16, 17 | anbi12i 733 |
. . . . . . . . . 10
       
      
          |
| 19 | 14, 18 | bitr4i 267 |
. . . . . . . . 9
      
      
         |
| 20 | | eleq2 2690 |
. . . . . . . . . . 11
                     |
| 21 | | eleq2 2690 |
. . . . . . . . . . 11
                     |
| 22 | 20, 21 | anbi12d 747 |
. . . . . . . . . 10
                                 |
| 23 | | velsn 4193 |
. . . . . . . . . . 11
     |
| 24 | | velsn 4193 |
. . . . . . . . . . 11
     |
| 25 | | equtr2 1954 |
. . . . . . . . . . 11
 
   |
| 26 | 23, 24, 25 | syl2anb 496 |
. . . . . . . . . 10
         |
| 27 | 22, 26 | syl6bi 243 |
. . . . . . . . 9
                           |
| 28 | 19, 27 | syl5bi 232 |
. . . . . . . 8
               
   |
| 29 | 28 | exlimiv 1858 |
. . . . . . 7
                     |
| 30 | 29 | impl 650 |
. . . . . 6
                     |
| 31 | 11, 30 | sylanb 489 |
. . . . 5
     Image Singleton           |
| 32 | 4, 31 | sylan2 491 |
. . . 4
     Image Singleton         Image Singleton         |
| 33 | 32 | gen2 1723 |
. . 3
         Image
Singleton       
 Image
Singleton         |
| 34 | 33 | ax-gen 1722 |
. 2
           Image Singleton       
 Image
Singleton         |
| 35 | | df-funpart 31981 |
. . . 4
Funpart   Image
Singleton      |
| 36 | 35 | funeqi 5909 |
. . 3
 Funpart   Image Singleton       |
| 37 | | dffun2 5898 |
. . 3
   Image
Singleton     
  Image Singleton                Image Singleton         Image Singleton           |
| 38 | 36, 37 | bitri 264 |
. 2
 Funpart    Image Singleton                Image Singleton         Image Singleton           |
| 39 | 1, 34, 38 | mpbir2an 955 |
1
Funpart |