| Step | Hyp | Ref
 | Expression | 
| 1 |   | df-en 6030 | 
. . 3
                          | 
| 2 |   | elrn2 4898 | 
. . . . 5
      
         Fns       Image Swap    Fns                        Fns       Image Swap    Fns     | 
| 3 |   | df-br 4641 | 
. . . . . . . . 9
     Fns              Fns   | 
| 4 |   | vex 2863 | 
. . . . . . . . . 10
        | 
| 5 | 4 | brfns 5834 | 
. . . . . . . . 9
     Fns            | 
| 6 | 3, 5 | bitr3i 242 | 
. . . . . . . 8
      
     Fns          | 
| 7 |   | elrn2 4898 | 
. . . . . . . . 9
      
         Image Swap    Fns                       Image Swap    Fns    | 
| 8 |   | oteltxp 5783 | 
. . . . . . . . . . . 12
      
            Image Swap    Fns         
      Image Swap             Fns    | 
| 9 |   | opelcnv 4894 | 
. . . . . . . . . . . . . 14
      
      Image Swap             Image Swap   | 
| 10 |   | dfcnv2 5101 | 
. . . . . . . . . . . . . . . 16
         Swap     | 
| 11 | 10 | eqeq2i 2363 | 
. . . . . . . . . . . . . . 15
                  Swap      | 
| 12 |   | vex 2863 | 
. . . . . . . . . . . . . . . 16
        | 
| 13 | 4, 12 | brimage 5794 | 
. . . . . . . . . . . . . . 15
    Image Swap           Swap      | 
| 14 |   | df-br 4641 | 
. . . . . . . . . . . . . . 15
    Image Swap              Image Swap   | 
| 15 | 11, 13, 14 | 3bitr2ri 265 | 
. . . . . . . . . . . . . 14
      
     Image Swap            | 
| 16 | 9, 15 | bitri 240 | 
. . . . . . . . . . . . 13
      
      Image Swap            | 
| 17 |   | df-br 4641 | 
. . . . . . . . . . . . . 14
     Fns              Fns   | 
| 18 | 12 | brfns 5834 | 
. . . . . . . . . . . . . 14
     Fns            | 
| 19 | 17, 18 | bitr3i 242 | 
. . . . . . . . . . . . 13
      
     Fns          | 
| 20 | 16, 19 | anbi12i 678 | 
. . . . . . . . . . . 12
              Image Swap             Fns       
               | 
| 21 | 8, 20 | bitri 240 | 
. . . . . . . . . . 11
      
            Image Swap    Fns                       | 
| 22 | 21 | exbii 1582 | 
. . . . . . . . . 10
            
        Image Swap    Fns         
               | 
| 23 | 4 | cnvex 5103 | 
. . . . . . . . . . 11
         | 
| 24 |   | fneq1 5174 | 
. . . . . . . . . . 11
              
        
      | 
| 25 | 23, 24 | ceqsexv 2895 | 
. . . . . . . . . 10
                                | 
| 26 | 22, 25 | bitri 240 | 
. . . . . . . . 9
            
        Image Swap    Fns             | 
| 27 | 7, 26 | bitri 240 | 
. . . . . . . 8
      
         Image Swap    Fns       
     | 
| 28 | 6, 27 | anbi12i 678 | 
. . . . . . 7
             Fns                Image Swap    Fns                        | 
| 29 |   | oteltxp 5783 | 
. . . . . . 7
      
            Fns       Image Swap    Fns                Fns                Image Swap    Fns     | 
| 30 |   | dff1o4 5295 | 
. . . . . . 7
                             | 
| 31 | 28, 29, 30 | 3bitr4i 268 | 
. . . . . 6
      
            Fns       Image Swap    Fns             | 
| 32 | 31 | exbii 1582 | 
. . . . 5
            
       
Fns       Image Swap    Fns                | 
| 33 | 2, 32 | bitri 240 | 
. . . 4
      
         Fns       Image Swap    Fns                | 
| 34 | 33 | opabbi2i 4867 | 
. . 3
      Fns       Image Swap    Fns                          | 
| 35 | 1, 34 | eqtr4i 2376 | 
. 2
         
Fns       Image Swap    Fns    | 
| 36 |   | fnsex 5833 | 
. . . 4
  Fns     | 
| 37 |   | swapex 4743 | 
. . . . . . . 8
   Swap      | 
| 38 | 37 | imageex 5802 | 
. . . . . . 7
  Image Swap      | 
| 39 | 38 | cnvex 5103 | 
. . . . . 6
   Image Swap      | 
| 40 | 39, 36 | txpex 5786 | 
. . . . 5
    Image Swap    Fns       | 
| 41 | 40 | rnex 5108 | 
. . . 4
      Image Swap    Fns       | 
| 42 | 36, 41 | txpex 5786 | 
. . 3
    Fns       Image Swap    Fns        | 
| 43 | 42 | rnex 5108 | 
. 2
      Fns       Image Swap    Fns        | 
| 44 | 35, 43 | eqeltri 2423 | 
1
        |