| Step | Hyp | Ref
| Expression |
| 1 | | 19.26 1798 |
. . 3
    
 
    |
| 2 | | equid 1939 |
. . . . . . . 8
 |
| 3 | 2 | a1i 11 |
. . . . . . 7
   |
| 4 | 3 | ax-gen 1722 |
. . . . . 6
     |
| 5 | 4 | a1i 11 |
. . . . 5
       |
| 6 | | equequ1 1952 |
. . . . . . . . 9
 
   |
| 7 | | equequ2 1953 |
. . . . . . . . 9
 
   |
| 8 | 6, 7 | sylan9bb 736 |
. . . . . . . 8
 
     |
| 9 | 8 | sps-o 34193 |
. . . . . . 7
     
   |
| 10 | | nfa1-o 34200 |
. . . . . . . 8
       |
| 11 | 9 | imbi2d 330 |
. . . . . . . 8
        
    |
| 12 | 10, 11 | albid 2090 |
. . . . . . 7
        

       |
| 13 | 9, 12 | imbi12d 334 |
. . . . . 6
           

        |
| 14 | 13 | adantr 481 |
. . . . 5
           
    

        |
| 15 | 5, 14 | mpbii 223 |
. . . 4
                  |
| 16 | 15 | exp32 631 |
. . 3
      

          |
| 17 | 1, 16 | sylbir 225 |
. 2
   
  
           |
| 18 | | equequ1 1952 |
. . . . . . 7
 
   |
| 19 | 18 | ad2antll 765 |
. . . . . 6
           |
| 20 | | axc9 2302 |
. . . . . . . . 9
 
  

    |
| 21 | 20 | impcom 446 |
. . . . . . . 8
    


   |
| 22 | 21 | adantrr 753 |
. . . . . . 7
            |
| 23 | | equtrr 1949 |
. . . . . . . 8
 
   |
| 24 | 23 | alimi 1739 |
. . . . . . 7
 
      |
| 25 | 22, 24 | syl6 35 |
. . . . . 6
               |
| 26 | 19, 25 | sylbid 230 |
. . . . 5
               |
| 27 | 26 | adantll 750 |
. . . 4
                  |
| 28 | | equequ1 1952 |
. . . . . . 7
 
   |
| 29 | 28 | sps-o 34193 |
. . . . . 6
 
    |
| 30 | 29 | imbi2d 330 |
. . . . . . 7
 
 


    |
| 31 | 30 | dral2-o 34215 |
. . . . . 6
 
   
   
    |
| 32 | 29, 31 | imbi12d 334 |
. . . . 5
 
 
    

        |
| 33 | 32 | ad2antrr 762 |
. . . 4
           
    

        |
| 34 | 27, 33 | mpbid 222 |
. . 3
                  |
| 35 | 34 | exp32 631 |
. 2
   

  

         |
| 36 | | equequ2 1953 |
. . . . . . 7
 
   |
| 37 | 36 | ad2antll 765 |
. . . . . 6
           |
| 38 | | axc9 2302 |
. . . . . . . . 9
 
  

    |
| 39 | 38 | imp 445 |
. . . . . . . 8
    


   |
| 40 | 39 | adantrr 753 |
. . . . . . 7
            |
| 41 | 36 | biimprcd 240 |
. . . . . . . 8
     |
| 42 | 41 | alimi 1739 |
. . . . . . 7
 
      |
| 43 | 40, 42 | syl6 35 |
. . . . . 6
               |
| 44 | 37, 43 | sylbid 230 |
. . . . 5
               |
| 45 | 44 | adantlr 751 |
. . . 4
   
              |
| 46 | 7 | sps-o 34193 |
. . . . . 6
 
    |
| 47 | 46 | imbi2d 330 |
. . . . . . 7
 
 


    |
| 48 | 47 | dral2-o 34215 |
. . . . . 6
 
       
    |
| 49 | 46, 48 | imbi12d 334 |
. . . . 5
 
 
    

        |
| 50 | 49 | ad2antlr 763 |
. . . 4
   
       
    

        |
| 51 | 45, 50 | mpbid 222 |
. . 3
   
              |
| 52 | 51 | exp32 631 |
. 2
   

  

         |
| 53 | | ax6ev 1890 |
. . . . 5

 |
| 54 | | ax6ev 1890 |
. . . . . . 7
  |
| 55 | | ax-1 6 |
. . . . . . . . . . 11
     |
| 56 | 55 | alrimiv 1855 |
. . . . . . . . . 10
       |
| 57 | | equequ1 1952 |
. . . . . . . . . . . . 13
 
   |
| 58 | | equequ2 1953 |
. . . . . . . . . . . . 13
 
   |
| 59 | 57, 58 | sylan9bb 736 |
. . . . . . . . . . . 12
 
     |
| 60 | 59 | adantl 482 |
. . . . . . . . . . 11
   
  
 

   |
| 61 | | dveeq2-o 34218 |
. . . . . . . . . . . . . . 15
 


   |
| 62 | | dveeq2-o 34218 |
. . . . . . . . . . . . . . 15
 


   |
| 63 | 61, 62 | im2anan9 880 |
. . . . . . . . . . . . . 14
    
 
   
    |
| 64 | 63 | imp 445 |
. . . . . . . . . . . . 13
   
  
 
 
    |
| 65 | | 19.26 1798 |
. . . . . . . . . . . . 13
    
 
    |
| 66 | 64, 65 | sylibr 224 |
. . . . . . . . . . . 12
   
  
 
      |
| 67 | | nfa1-o 34200 |
. . . . . . . . . . . . 13
       |
| 68 | 59 | sps-o 34193 |
. . . . . . . . . . . . . 14
     
   |
| 69 | 68 | imbi2d 330 |
. . . . . . . . . . . . 13
        
    |
| 70 | 67, 69 | albid 2090 |
. . . . . . . . . . . 12
        

       |
| 71 | 66, 70 | syl 17 |
. . . . . . . . . . 11
   
  
 
   

       |
| 72 | 60, 71 | imbi12d 334 |
. . . . . . . . . 10
   
  
 
    
 

        |
| 73 | 56, 72 | mpbii 223 |
. . . . . . . . 9
   
  
 

       |
| 74 | 73 | exp32 631 |
. . . . . . . 8
    

    
      |
| 75 | 74 | exlimdv 1861 |
. . . . . . 7
    
 
 
         |
| 76 | 54, 75 | mpi 20 |
. . . . . 6
    

         |
| 77 | 76 | exlimdv 1861 |
. . . . 5
    
 
         |
| 78 | 53, 77 | mpi 20 |
. . . 4
    

       |
| 79 | 78 | a1d 25 |
. . 3
    

         |
| 80 | 79 | a1d 25 |
. 2
    
  

         |
| 81 | 17, 35, 52, 80 | 4cases 990 |
1
 

         |