| Step | Hyp | Ref
 | Expression | 
| 1 |   | iftrue 3669 | 
. . . . . . . . 9
       Nn         Nn        1c             1c   | 
| 2 | 1 | eqcomd 2358 | 
. . . . . . . 8
       Nn       
1c 
     
  Nn        1c       | 
| 3 |   | eleq1 2413 | 
. . . . . . . . . . 11
               
Nn      
Nn    | 
| 4 |   | addceq1 4384 | 
. . . . . . . . . . 11
                1c         1c   | 
| 5 |   | id 19 | 
. . . . . . . . . . 11
                  | 
| 6 | 3, 4, 5 | ifbieq12d 3685 | 
. . . . . . . . . 10
              
  Nn        1c           
  Nn        1c       | 
| 7 | 6 | eqeq2d 2364 | 
. . . . . . . . 9
              
 
1c 
     
  Nn        1c             1c   
     
Nn       
1c        | 
| 8 | 7 | rspcev 2956 | 
. . . . . . . 8
              
 
1c 
     
  Nn        1c           
      
 
1c 
     
  Nn        1c       | 
| 9 | 2, 8 | sylan2 460 | 
. . . . . . 7
               
Nn                 1c          Nn        1c       | 
| 10 | 9 | ancoms 439 | 
. . . . . 6
        Nn                        1c          Nn        1c       | 
| 11 |   | vex 2863 | 
. . . . . . . 8
        | 
| 12 |   | 1cex 4143 | 
. . . . . . . 8
 
1c  
  | 
| 13 | 11, 12 | addcex 4395 | 
. . . . . . 7
       1c   
  | 
| 14 |   | eqeq1 2359 | 
. . . . . . . 8
            1c            
  Nn        1c             1c   
     
Nn       
1c        | 
| 15 | 14 | rexbidv 2636 | 
. . . . . . 7
            1c                   
  Nn        1c                    1c          Nn        1c        | 
| 16 |   | df-phi 4566 | 
. . . . . . 7
   Phi                    
     
Nn       
1c       | 
| 17 | 13, 15, 16 | elab2 2989 | 
. . . . . 6
       
1c 
   Phi                 1c          Nn        1c       | 
| 18 | 10, 17 | sylibr 203 | 
. . . . 5
        Nn                 1c     Phi    | 
| 19 |   | eleq2 2414 | 
. . . . . . . . 9
    Phi
     Phi
       
 
1c 
   Phi          1c     Phi     | 
| 20 | 19 | biimpac 472 | 
. . . . . . . 8
        
1c 
   Phi      Phi      Phi           1c     Phi    | 
| 21 | 14 | rexbidv 2636 | 
. . . . . . . . . 10
            1c                   
  Nn        1c                    1c          Nn        1c        | 
| 22 |   | df-phi 4566 | 
. . . . . . . . . 10
   Phi                    
     
Nn       
1c       | 
| 23 | 13, 21, 22 | elab2 2989 | 
. . . . . . . . 9
       
1c 
   Phi                 1c          Nn        1c       | 
| 24 |   | iffalse 3670 | 
. . . . . . . . . . . . . . . . . . 19
         Nn         Nn       
1c           | 
| 25 | 24 | eqeq2d 2364 | 
. . . . . . . . . . . . . . . . . 18
         Nn         1c   
     
Nn       
1c            
1c 
      | 
| 26 | 25 | biimpac 472 | 
. . . . . . . . . . . . . . . . 17
        
1c 
     
  Nn        1c             
Nn          1c   
   | 
| 27 |   | peano2 4404 | 
. . . . . . . . . . . . . . . . . 18
       Nn       
1c 
  Nn   | 
| 28 |   | eleq1 2413 | 
. . . . . . . . . . . . . . . . . 18
       
1c 
            1c    Nn       Nn    | 
| 29 | 27, 28 | syl5ibcom 211 | 
. . . . . . . . . . . . . . . . 17
       Nn         1c     
      Nn    | 
| 30 | 26, 29 | syl5 28 | 
. . . . . . . . . . . . . . . 16
       Nn          1c   
     
Nn       
1c              Nn         Nn    | 
| 31 | 30 | expdimp 426 | 
. . . . . . . . . . . . . . 15
        Nn        1c          Nn        1c                Nn       Nn    | 
| 32 | 31 | pm2.18d 103 | 
. . . . . . . . . . . . . 14
        Nn        1c          Nn        1c             Nn   | 
| 33 |   | simpl 443 | 
. . . . . . . . . . . . . 14
        Nn        1c          Nn        1c             Nn   | 
| 34 |   | simpr 447 | 
. . . . . . . . . . . . . . 15
        Nn        1c          Nn        1c              1c   
     
Nn       
1c       | 
| 35 |   | iftrue 3669 | 
. . . . . . . . . . . . . . . 16
       Nn         Nn        1c             1c   | 
| 36 | 32, 35 | syl 15 | 
. . . . . . . . . . . . . . 15
        Nn        1c          Nn        1c               Nn        1c            
1c   | 
| 37 | 34, 36 | eqtr2d 2386 | 
. . . . . . . . . . . . . 14
        Nn        1c          Nn        1c              1c   
     1c   | 
| 38 |   | peano4 4558 | 
. . . . . . . . . . . . . 14
        Nn       Nn        1c        
1c            | 
| 39 | 32, 33, 37, 38 | syl3anc 1182 | 
. . . . . . . . . . . . 13
        Nn        1c          Nn        1c                | 
| 40 | 39 | 3adant2 974 | 
. . . . . . . . . . . 12
        Nn               
1c 
     
  Nn        1c            
   | 
| 41 |   | simp2 956 | 
. . . . . . . . . . . 12
        Nn               
1c 
     
  Nn        1c            
   | 
| 42 | 40, 41 | eqeltrrd 2428 | 
. . . . . . . . . . 11
        Nn               
1c 
     
  Nn        1c            
   | 
| 43 | 42 | 3expia 1153 | 
. . . . . . . . . 10
        Nn                  1c   
     
Nn       
1c                | 
| 44 | 43 | rexlimdva 2739 | 
. . . . . . . . 9
       Nn                1c          Nn        1c                | 
| 45 | 23, 44 | syl5bi 208 | 
. . . . . . . 8
       Nn         1c     Phi             | 
| 46 | 20, 45 | syl5 28 | 
. . . . . . 7
       Nn          1c   
 Phi      Phi      Phi              | 
| 47 | 46 | exp3a 425 | 
. . . . . 6
       Nn         1c     Phi       Phi      Phi              | 
| 48 | 47 | adantr 451 | 
. . . . 5
        Nn                  1c   
 Phi       Phi      Phi              | 
| 49 | 18, 48 | mpd 14 | 
. . . 4
        Nn              Phi      Phi             | 
| 50 |   | iffalse 3670 | 
. . . . . . . . 9
         Nn         Nn       
1c           | 
| 51 | 50 | eqcomd 2358 | 
. . . . . . . 8
         Nn          
  Nn        1c       | 
| 52 | 6 | eqeq2d 2364 | 
. . . . . . . . 9
               
     
Nn       
1c                  Nn        1c        | 
| 53 | 52 | rspcev 2956 | 
. . . . . . . 8
               
     
Nn       
1c                       
  Nn        1c       | 
| 54 | 51, 53 | sylan2 460 | 
. . . . . . 7
               
  Nn                   
  Nn        1c       | 
| 55 | 54 | ancoms 439 | 
. . . . . 6
          Nn                          
  Nn        1c       | 
| 56 |   | eqeq1 2359 | 
. . . . . . . 8
               
     
Nn       
1c                  Nn        1c        | 
| 57 | 56 | rexbidv 2636 | 
. . . . . . 7
              
       
     
Nn       
1c                  
     
Nn       
1c        | 
| 58 | 11, 57, 16 | elab2 2989 | 
. . . . . 6
        Phi               
     
Nn       
1c       | 
| 59 | 55, 58 | sylibr 203 | 
. . . . 5
          Nn                
Phi    | 
| 60 |   | eleq2 2414 | 
. . . . . . . . 9
    Phi
     Phi
        
 Phi          Phi     | 
| 61 | 60 | biimpac 472 | 
. . . . . . . 8
         Phi      Phi      Phi           Phi    | 
| 62 | 56 | rexbidv 2636 | 
. . . . . . . . . 10
              
       
     
Nn       
1c                  
     
Nn       
1c        | 
| 63 | 11, 62, 22 | elab2 2989 | 
. . . . . . . . 9
        Phi               
     
Nn       
1c       | 
| 64 |   | simpr 447 | 
. . . . . . . . . . . . . 14
          Nn          
  Nn        1c            
     
Nn       
1c       | 
| 65 | 35 | eqeq2d 2364 | 
. . . . . . . . . . . . . . . . . . 19
       Nn           
  Nn        1c                
1c    | 
| 66 |   | peano2 4404 | 
. . . . . . . . . . . . . . . . . . . 20
       Nn       
1c 
  Nn   | 
| 67 |   | eleq1a 2422 | 
. . . . . . . . . . . . . . . . . . . 20
       
1c 
  Nn            
1c 
      Nn    | 
| 68 | 66, 67 | syl 15 | 
. . . . . . . . . . . . . . . . . . 19
       Nn            
1c 
      Nn    | 
| 69 | 65, 68 | sylbid 206 | 
. . . . . . . . . . . . . . . . . 18
       Nn           
  Nn        1c            Nn    | 
| 70 | 69 | com12 27 | 
. . . . . . . . . . . . . . . . 17
             Nn       
1c             Nn       Nn    | 
| 71 | 70 | con3d 125 | 
. . . . . . . . . . . . . . . 16
             Nn       
1c               Nn        
Nn    | 
| 72 | 71 | impcom 419 | 
. . . . . . . . . . . . . . 15
          Nn          
  Nn        1c            
  Nn   | 
| 73 | 72, 24 | syl 15 | 
. . . . . . . . . . . . . 14
          Nn          
  Nn        1c               Nn        1c           | 
| 74 | 64, 73 | eqtr2d 2386 | 
. . . . . . . . . . . . 13
          Nn          
  Nn        1c            
   | 
| 75 | 74 | adantlr 695 | 
. . . . . . . . . . . 12
           Nn                      Nn        1c                | 
| 76 |   | simplr 731 | 
. . . . . . . . . . . 12
           Nn                      Nn        1c                | 
| 77 | 75, 76 | eqeltrrd 2428 | 
. . . . . . . . . . 11
           Nn                      Nn        1c                | 
| 78 | 77 | ex 423 | 
. . . . . . . . . 10
          Nn                       Nn        1c                | 
| 79 | 78 | rexlimdva 2739 | 
. . . . . . . . 9
         Nn                  
  Nn        1c                | 
| 80 | 63, 79 | syl5bi 208 | 
. . . . . . . 8
         Nn         Phi        
    | 
| 81 | 61, 80 | syl5 28 | 
. . . . . . 7
         Nn          Phi      Phi      Phi              | 
| 82 | 81 | exp3a 425 | 
. . . . . 6
         Nn         Phi       Phi      Phi              | 
| 83 | 82 | adantr 451 | 
. . . . 5
          Nn                  Phi       Phi      Phi              | 
| 84 | 59, 83 | mpd 14 | 
. . . 4
          Nn              Phi      Phi             | 
| 85 | 49, 84 | pm2.61ian 765 | 
. . 3
             Phi      Phi        
    | 
| 86 | 85 | com12 27 | 
. 2
    Phi
     Phi
        
       
    | 
| 87 | 86 | ssrdv 3279 | 
1
    Phi
     Phi
           |