| Step | Hyp | Ref
| Expression |
| 1 | | 19.26 1593 |
. . 3
   
   
   |
| 2 | | equid 1676 |
. . . . . . . 8
 |
| 3 | 2 | a1i 10 |
. . . . . . 7
   |
| 4 | 3 | ax-gen 1546 |
. . . . . 6
  
  |
| 5 | 4 | a1i 10 |
. . . . 5
       |
| 6 | | equequ1 1684 |
. . . . . . . . 9
 
   |
| 7 | | equequ2 1686 |
. . . . . . . . 9
 
   |
| 8 | 6, 7 | sylan9bb 680 |
. . . . . . . 8
 
     |
| 9 | 8 | sps-o 2159 |
. . . . . . 7
   
     |
| 10 | | nfa1-o 2166 |
. . . . . . . 8
       |
| 11 | 9 | imbi2d 307 |
. . . . . . . 8
   
         |
| 12 | 10, 11 | albid 1772 |
. . . . . . 7
   
    
        |
| 13 | 9, 12 | imbi12d 311 |
. . . . . 6
   
           
     |
| 14 | 13 | adantr 451 |
. . . . 5
                          |
| 15 | 5, 14 | mpbii 202 |
. . . 4
          
       |
| 16 | 15 | exp32 588 |
. . 3
   
  
           |
| 17 | 1, 16 | sylbir 204 |
. 2
  
    

         |
| 18 | | equequ1 1684 |
. . . . . . 7
 
   |
| 19 | 18 | ad2antll 709 |
. . . . . 6
       
   |
| 20 | | ax12o 1934 |
. . . . . . . . 9
 
 
      |
| 21 | 20 | impcom 419 |
. . . . . . . 8
      
   |
| 22 | 21 | adantrr 697 |
. . . . . . 7
       
    |
| 23 | | equtrr 1683 |
. . . . . . . 8
 
   |
| 24 | 23 | alimi 1559 |
. . . . . . 7
 
      |
| 25 | 22, 24 | syl6 29 |
. . . . . 6
       
       |
| 26 | 19, 25 | sylbid 206 |
. . . . 5
       
       |
| 27 | 26 | adantll 694 |
. . . 4
       
  
       |
| 28 | | equequ1 1684 |
. . . . . . 7
 
   |
| 29 | 28 | sps-o 2159 |
. . . . . 6
 
    |
| 30 | 29 | imbi2d 307 |
. . . . . . 7
 
        |
| 31 | 30 | dral2-o 2181 |
. . . . . 6
 
   
        |
| 32 | 29, 31 | imbi12d 311 |
. . . . 5
 
    
     
     |
| 33 | 32 | ad2antrr 706 |
. . . 4
       
   
              |
| 34 | 27, 33 | mpbid 201 |
. . 3
       
  
       |
| 35 | 34 | exp32 588 |
. 2
  

  

          |
| 36 | | equequ2 1686 |
. . . . . . 7
 
   |
| 37 | 36 | ad2antll 709 |
. . . . . 6
       
   |
| 38 | | ax12o 1934 |
. . . . . . . . 9
 
 
      |
| 39 | 38 | imp 418 |
. . . . . . . 8
      
   |
| 40 | 39 | adantrr 697 |
. . . . . . 7
       
    |
| 41 | 36 | biimprcd 216 |
. . . . . . . 8
 
   |
| 42 | 41 | alimi 1559 |
. . . . . . 7
 
      |
| 43 | 40, 42 | syl6 29 |
. . . . . 6
       
       |
| 44 | 37, 43 | sylbid 206 |
. . . . 5
       
       |
| 45 | 44 | adantlr 695 |
. . . 4
   
   
  
       |
| 46 | 7 | sps-o 2159 |
. . . . . 6
 
    |
| 47 | 46 | imbi2d 307 |
. . . . . . 7
 
        |
| 48 | 47 | dral2-o 2181 |
. . . . . 6
 
   
        |
| 49 | 46, 48 | imbi12d 311 |
. . . . 5
 
    
     
     |
| 50 | 49 | ad2antlr 707 |
. . . 4
   
   
   
              |
| 51 | 45, 50 | mpbid 201 |
. . 3
   
   
  
       |
| 52 | 51 | exp32 588 |
. 2
   
  
           |
| 53 | | a9ev 1656 |
. . . . 5

 |
| 54 | | a9ev 1656 |
. . . . . . 7

 |
| 55 | | ax-1 6 |
. . . . . . . . . . 11
 
   |
| 56 | 55 | alrimiv 1631 |
. . . . . . . . . 10
       |
| 57 | | equequ1 1684 |
. . . . . . . . . . . . 13
 
   |
| 58 | | equequ2 1686 |
. . . . . . . . . . . . 13
 
   |
| 59 | 57, 58 | sylan9bb 680 |
. . . . . . . . . . . 12
 
     |
| 60 | 59 | adantl 452 |
. . . . . . . . . . 11
   
  
      |
| 61 | | dveeq2-o 2184 |
. . . . . . . . . . . . . . 15
 
 
   |
| 62 | | dveeq2-o 2184 |
. . . . . . . . . . . . . . 15
 
 
   |
| 63 | 61, 62 | im2anan9 808 |
. . . . . . . . . . . . . 14
      
   
    |
| 64 | 63 | imp 418 |
. . . . . . . . . . . . 13
   
  
   
    |
| 65 | | 19.26 1593 |
. . . . . . . . . . . . 13
   
   
   |
| 66 | 64, 65 | sylibr 203 |
. . . . . . . . . . . 12
   
  
    
   |
| 67 | | nfa1-o 2166 |
. . . . . . . . . . . . 13
       |
| 68 | 59 | sps-o 2159 |
. . . . . . . . . . . . . 14
   
     |
| 69 | 68 | imbi2d 307 |
. . . . . . . . . . . . 13
   
         |
| 70 | 67, 69 | albid 1772 |
. . . . . . . . . . . 12
   
    
        |
| 71 | 66, 70 | syl 15 |
. . . . . . . . . . 11
   
  
     
        |
| 72 | 60, 71 | imbi12d 311 |
. . . . . . . . . 10
   
  
            
     |
| 73 | 56, 72 | mpbii 202 |
. . . . . . . . 9
   
  
     
    |
| 74 | 73 | exp32 588 |
. . . . . . . 8
      

         |
| 75 | 74 | exlimdv 1636 |
. . . . . . 7
      
           |
| 76 | 54, 75 | mpi 16 |
. . . . . 6
      
        |
| 77 | 76 | exlimdv 1636 |
. . . . 5
      
         |
| 78 | 53, 77 | mpi 16 |
. . . 4
             |
| 79 | 78 | a1d 22 |
. . 3
      
        |
| 80 | 79 | a1d 22 |
. 2
      
           |
| 81 | 17, 35, 52, 80 | 4cases 915 |
1
 
          |