| Step | Hyp | Ref
 | Expression | 
| 1 |   | nulnnc 6119 | 
. . . . . . 7
        NC | 
| 2 |   | eleq1 2413 | 
. . . . . . 7
        
      
NC       NC    | 
| 3 | 1, 2 | mtbiri 294 | 
. . . . . 6
        
        NC   | 
| 4 | 3 | necon2ai 2562 | 
. . . . 5
       NC          | 
| 5 |   | n0 3560 | 
. . . . 5
        
 
      
   | 
| 6 | 4, 5 | sylib 188 | 
. . . 4
       NC             | 
| 7 |   | vex 2863 | 
. . . . . . . . . 10
        | 
| 8 | 7 | pw1ex 4304 | 
. . . . . . . . 9
   1       | 
| 9 | 8 | ncelncsi 6122 | 
. . . . . . . 8
  Nc  1  
  NC | 
| 10 |   | eqid 2353 | 
. . . . . . . 8
  Nc  1  
  Nc  1   | 
| 11 |   | eqeq1 2359 | 
. . . . . . . . 9
       Nc  1          Nc  1     Nc  1  
  Nc  1     | 
| 12 | 11 | rspcev 2956 | 
. . . . . . . 8
     Nc  1     NC   Nc  1  
  Nc  1          
NC     Nc  1    | 
| 13 | 9, 10, 12 | mp2an 653 | 
. . . . . . 7
       NC     Nc  1   | 
| 14 | 13 | jctr 526 | 
. . . . . 6
               
         NC     Nc  1     | 
| 15 | 14 | a1i 10 | 
. . . . 5
       NC                          NC     Nc  1      | 
| 16 | 15 | eximdv 1622 | 
. . . 4
       NC                               NC     Nc  1      | 
| 17 | 6, 16 | mpd 14 | 
. . 3
       NC                  
NC     Nc  1     | 
| 18 |   | rexcom 2773 | 
. . . 4
       
NC   
       
Nc  1                 NC     Nc  1    | 
| 19 |   | df-rex 2621 | 
. . . 4
       
       NC     Nc  1                    
NC     Nc  1     | 
| 20 | 18, 19 | bitri 240 | 
. . 3
       
NC   
       
Nc  1                     NC     Nc  1     | 
| 21 | 17, 20 | sylibr 203 | 
. 2
       NC        NC           
Nc  1    | 
| 22 |   | reeanv 2779 | 
. . . 4
       
              Nc  1        
Nc  1   
 
     
      Nc  1               
Nc  1     | 
| 23 |   | ncseqnc 6129 | 
. . . . . . . . . . . 12
       NC        Nc             | 
| 24 | 23 | biimpar 471 | 
. . . . . . . . . . 11
        NC                Nc    | 
| 25 | 24 | adantrr 697 | 
. . . . . . . . . 10
        NC                         
Nc    | 
| 26 |   | ncseqnc 6129 | 
. . . . . . . . . . . 12
       NC        Nc             | 
| 27 | 26 | biimpar 471 | 
. . . . . . . . . . 11
        NC                Nc    | 
| 28 | 27 | adantrl 696 | 
. . . . . . . . . 10
        NC                         
Nc    | 
| 29 | 25, 28 | eqtr3d 2387 | 
. . . . . . . . 9
        NC                      Nc     Nc    | 
| 30 | 7 | ncpw1 6153 | 
. . . . . . . . 9
    Nc     Nc     Nc  1    
Nc  1    | 
| 31 | 29, 30 | sylib 188 | 
. . . . . . . 8
        NC                      Nc  1     Nc  1    | 
| 32 | 31 | 3adant2 974 | 
. . . . . . 7
        NC        NC       NC               
     
  Nc  1  
  Nc  1    | 
| 33 |   | eqeq2 2362 | 
. . . . . . . . 9
    Nc  1  
  Nc  1          Nc  1         Nc  1     | 
| 34 | 33 | anbi1d 685 | 
. . . . . . . 8
    Nc  1  
  Nc  1           Nc  1  
      Nc  1           Nc  1        
Nc  1      | 
| 35 |   | eqtr3 2372 | 
. . . . . . . 8
        Nc  1         Nc  1             | 
| 36 | 34, 35 | syl6bi 219 | 
. . . . . . 7
    Nc  1  
  Nc  1           Nc  1  
      Nc  1              | 
| 37 | 32, 36 | syl 15 | 
. . . . . 6
        NC        NC       NC               
     
     
  Nc  1  
      Nc  1              | 
| 38 | 37 | 3expa 1151 | 
. . . . 5
         NC        NC       NC                               Nc  1  
      Nc  1              | 
| 39 | 38 | rexlimdvva 2746 | 
. . . 4
        NC        NC       NC           
              Nc  1        
Nc  1   
          | 
| 40 | 22, 39 | syl5bir 209 | 
. . 3
        NC        NC       NC          
       
Nc  1                Nc  1              | 
| 41 | 40 | ralrimivva 2707 | 
. 2
       NC        NC      NC              Nc  1  
             Nc  1              | 
| 42 |   | eqeq1 2359 | 
. . . . 5
               
Nc  1         Nc  1     | 
| 43 | 42 | rexbidv 2636 | 
. . . 4
              
       
Nc  1                Nc  1     | 
| 44 |   | pw1eq 4144 | 
. . . . . . 7
            1      1    | 
| 45 | 44 | nceqd 6111 | 
. . . . . 6
           Nc  1  
  Nc  1    | 
| 46 | 45 | eqeq2d 2364 | 
. . . . 5
               
Nc  1         Nc  1     | 
| 47 | 46 | cbvrexv 2837 | 
. . . 4
       
      Nc  1               
Nc  1    | 
| 48 | 43, 47 | syl6bb 252 | 
. . 3
              
       
Nc  1                Nc  1     | 
| 49 | 48 | reu4 3031 | 
. 2
        NC           
Nc  1           NC     
      Nc  1          NC      NC              Nc  1  
             Nc  1               | 
| 50 | 21, 41, 49 | sylanbrc 645 | 
1
       NC        NC           
Nc  1    |