| Step | Hyp | Ref
| Expression |
| 1 | | insklem.1 |
. . 3
 1 1c k  k    |
| 2 | | insklem.2 |
. . 3
 1 1c k  k    |
| 3 | | ssofeq 4078 |
. . 3
 
 1 1c k  k    1 1c k  k    

 1 1c k  k         |
| 4 | 1, 2, 3 | mp2an 653 |
. 2
   1 1c k  k        |
| 5 | | 19.23v 1891 |
. . . . 5
      
          
       
          
    |
| 6 | | 19.23vv 1892 |
. . . . . 6
               

           
   

    |
| 7 | 6 | albii 1566 |
. . . . 5
       
          
       
          
    |
| 8 | | 19.42vv 1907 |
. . . . . . . . . 10
      1 1c      1 1c          |
| 9 | 8 | anbi2i 675 |
. . . . . . . . 9
    
     1 1c
          1 1c           |
| 10 | | 19.42vv 1907 |
. . . . . . . . 9
          1 1c
              1 1c        |
| 11 | | elvvk 4208 |
. . . . . . . . . . 11
  k    
     |
| 12 | 11 | anbi2i 675 |
. . . . . . . . . 10
  1
1c  k    1 1c          |
| 13 | 12 | anbi2i 675 |
. . . . . . . . 9
    

1
1c  k         1 1c           |
| 14 | 9, 10, 13 | 3bitr4ri 269 |
. . . . . . . 8
    

1
1c  k             1 1c        |
| 15 | 14 | 2exbii 1583 |
. . . . . . 7
          1 1c
 k                
1
1c        |
| 16 | | elxpk 4197 |
. . . . . . 7
  1
1c k  k            1 1c  k      |
| 17 | | exrot3 1744 |
. . . . . . . 8
     
                           |
| 18 | | exancom 1586 |
. . . . . . . . . . . 12
          1 1c   
1 1c          |
| 19 | | elpw11c 4148 |
. . . . . . . . . . . . . . 15
 1 1c        |
| 20 | 19 | anbi1i 676 |
. . . . . . . . . . . . . 14
  1
1c         
             |
| 21 | | 19.41v 1901 |
. . . . . . . . . . . . . 14
       
                      |
| 22 | 20, 21 | bitr4i 243 |
. . . . . . . . . . . . 13
  1
1c                        |
| 23 | 22 | exbii 1582 |
. . . . . . . . . . . 12
    1 1c                
         |
| 24 | 18, 23 | bitri 240 |
. . . . . . . . . . 11
          1 1c         
         |
| 25 | | ancom 437 |
. . . . . . . . . . . . . . 15
  1
1c         1 1c  |
| 26 | 25 | anbi2i 675 |
. . . . . . . . . . . . . 14
    

1
1c          
  
1 1c   |
| 27 | | an12 772 |
. . . . . . . . . . . . . 14
    

  
1 1c
        1
1c   |
| 28 | 26, 27 | bitri 240 |
. . . . . . . . . . . . 13
    

1
1c          
  
1 1c   |
| 29 | 28 | 2exbii 1583 |
. . . . . . . . . . . 12
          1 1c
                 1 1c   |
| 30 | | opkex 4114 |
. . . . . . . . . . . . . 14
  
 |
| 31 | | opkeq2 4061 |
. . . . . . . . . . . . . . . 16
               |
| 32 | 31 | eqeq2d 2364 |
. . . . . . . . . . . . . . 15
                 |
| 33 | 32 | anbi1d 685 |
. . . . . . . . . . . . . 14
         1 1c        1 1c   |
| 34 | 30, 33 | ceqsexv 2895 |
. . . . . . . . . . . . 13
       
  
1 1c
       1 1c  |
| 35 | 34 | exbii 1582 |
. . . . . . . . . . . 12
             1
1c   
     
1 1c  |
| 36 | 29, 35 | bitri 240 |
. . . . . . . . . . 11
          1 1c
       
     
1 1c  |
| 37 | | snex 4112 |
. . . . . . . . . . . . . 14
     |
| 38 | | opkeq1 4060 |
. . . . . . . . . . . . . . 15
                       |
| 39 | 38 | eqeq2d 2364 |
. . . . . . . . . . . . . 14
                 
       |
| 40 | 37, 39 | ceqsexv 2895 |
. . . . . . . . . . . . 13
       
                   |
| 41 | 40 | exbii 1582 |
. . . . . . . . . . . 12
                 
            |
| 42 | | excom 1741 |
. . . . . . . . . . . 12
                         
         |
| 43 | 41, 42 | bitr3i 242 |
. . . . . . . . . . 11
 
                  
         |
| 44 | 24, 36, 43 | 3bitr4ri 269 |
. . . . . . . . . 10
 
                   1 1c        |
| 45 | 44 | 2exbii 1583 |
. . . . . . . . 9
     
                      
1
1c        |
| 46 | | exrot4 1745 |
. . . . . . . . 9
              1 1c                  
1
1c        |
| 47 | 45, 46 | bitri 240 |
. . . . . . . 8
     
                      
1
1c        |
| 48 | 17, 47 | bitri 240 |
. . . . . . 7
     
                      
1
1c        |
| 49 | 15, 16, 48 | 3bitr4i 268 |
. . . . . 6
  1
1c k  k                    |
| 50 | 49 | imbi1i 315 |
. . . . 5
   1 1c k  k   
       
          
    |
| 51 | 5, 7, 50 | 3bitr4ri 269 |
. . . 4
   1 1c k  k   
                   
    |
| 52 | 51 | albii 1566 |
. . 3
     1 1c k  k   
                          |
| 53 | | df-ral 2620 |
. . 3
 
 1 1c k  k        
 1 1c k  k   
    |
| 54 | | alcom 1737 |
. . . 4
               
   

                          |
| 55 | | alrot3 1738 |
. . . . 5
       
          
                   
    |
| 56 | 55 | albii 1566 |
. . . 4
               
   

                          |
| 57 | | opkex 4114 |
. . . . . . 7
           |
| 58 | | eleq1 2413 |
. . . . . . . 8
          

             |
| 59 | | eleq1 2413 |
. . . . . . . 8
          

             |
| 60 | 58, 59 | bibi12d 312 |
. . . . . . 7
          
 
           
     
   
    |
| 61 | 57, 60 | ceqsalv 2886 |
. . . . . 6
                
                        |
| 62 | 61 | albii 1566 |
. . . . 5
               

              
     
   
   |
| 63 | 62 | 2albii 1567 |
. . . 4
               
   

              
   
     
   
   |
| 64 | 54, 56, 63 | 3bitrri 263 |
. . 3
                 
     
   
                   

    |
| 65 | 52, 53, 64 | 3bitr4i 268 |
. 2
 
 1 1c k  k                  
   
     
   
   |
| 66 | 4, 65 | bitri 240 |
1
             
   
     
   
   |