| Step | Hyp | Ref
 | Expression | 
| 1 |   | n0 3560 | 
. . 3
       
1c 
            
     1c   | 
| 2 |   | peano2 4404 | 
. . . . . . . 8
       Nn       
1c 
  Nn   | 
| 3 |   | tfincl 4493 | 
. . . . . . . 8
       
1c 
  Nn   Tfin      1c    Nn   | 
| 4 | 2, 3 | syl 15 | 
. . . . . . 7
       Nn   Tfin      1c   
Nn   | 
| 5 | 4 | adantr 451 | 
. . . . . 6
        Nn           
1c     Tfin   
 
1c 
  Nn   | 
| 6 |   | tfincl 4493 | 
. . . . . . . 8
       Nn   Tfin     Nn   | 
| 7 |   | peano2 4404 | 
. . . . . . . 8
    Tfin    
Nn     Tfin     1c   
Nn   | 
| 8 | 6, 7 | syl 15 | 
. . . . . . 7
       Nn     Tfin     1c   
Nn   | 
| 9 | 8 | adantr 451 | 
. . . . . 6
        Nn           
1c       Tfin     1c    Nn   | 
| 10 |   | tfinpw1 4495 | 
. . . . . . 7
        
1c 
  Nn           
1c      1     Tfin      1c   | 
| 11 | 2, 10 | sylan 457 | 
. . . . . 6
        Nn           
1c      1     Tfin      1c   | 
| 12 |   | elsuc 4414 | 
. . . . . . . 8
            1c      
      
  ∼                 | 
| 13 |   | tfinpw1 4495 | 
. . . . . . . . . . . 12
        Nn             1  
  Tfin    | 
| 14 | 13 | adantrr 697 | 
. . . . . . . . . . 11
        Nn                ∼        1     Tfin    | 
| 15 |   | vex 2863 | 
. . . . . . . . . . . . . . 15
        | 
| 16 | 15 | elcompl 3226 | 
. . . . . . . . . . . . . 14
       ∼              | 
| 17 |   | snelpw1 4147 | 
. . . . . . . . . . . . . 14
          1            | 
| 18 | 16, 17 | xchbinxr 302 | 
. . . . . . . . . . . . 13
       ∼              1    | 
| 19 | 18 | biimpi 186 | 
. . . . . . . . . . . 12
       ∼              1    | 
| 20 | 19 | ad2antll 709 | 
. . . . . . . . . . 11
        Nn                ∼                1    | 
| 21 |   | snex 4112 | 
. . . . . . . . . . . 12
       
  | 
| 22 | 21 | elsuci 4415 | 
. . . . . . . . . . 11
     1  
  Tfin            
 1        1  
             Tfin     1c   | 
| 23 | 14, 20, 22 | syl2anc 642 | 
. . . . . . . . . 10
        Nn                ∼         1                Tfin     1c   | 
| 24 |   | pw1eq 4144 | 
. . . . . . . . . . . 12
                    1      1            | 
| 25 |   | pw1un 4164 | 
. . . . . . . . . . . . 13
   1            
  1      1      | 
| 26 | 15 | pw1sn 4166 | 
. . . . . . . . . . . . . 14
   1      
      | 
| 27 | 26 | uneq2i 3416 | 
. . . . . . . . . . . . 13
    1      1          1  
         | 
| 28 | 25, 27 | eqtri 2373 | 
. . . . . . . . . . . 12
   1            
  1            | 
| 29 | 24, 28 | syl6eq 2401 | 
. . . . . . . . . . 11
                    1       1             | 
| 30 | 29 | eleq1d 2419 | 
. . . . . . . . . 10
                     1  
    Tfin     1c      1             
  Tfin     1c    | 
| 31 | 23, 30 | syl5ibrcom 213 | 
. . . . . . . . 9
        Nn                ∼           
             1  
    Tfin     1c    | 
| 32 | 31 | rexlimdvva 2746 | 
. . . . . . . 8
       Nn                ∼   
               1  
    Tfin     1c    | 
| 33 | 12, 32 | syl5bi 208 | 
. . . . . . 7
       Nn            
1c 
   1       Tfin     1c    | 
| 34 | 33 | imp 418 | 
. . . . . 6
        Nn           
1c      1       Tfin     1c   | 
| 35 |   | nnceleq 4431 | 
. . . . . 6
      Tfin      1c    Nn     Tfin     1c    Nn       1    
Tfin     
1c 
   1       Tfin     1c      Tfin   
 
1c 
    Tfin     1c   | 
| 36 | 5, 9, 11, 34, 35 | syl22anc 1183 | 
. . . . 5
        Nn           
1c     Tfin   
 
1c 
    Tfin     1c   | 
| 37 | 36 | ex 423 | 
. . . 4
       Nn            
1c 
  Tfin   
 
1c 
    Tfin     1c    | 
| 38 | 37 | exlimdv 1636 | 
. . 3
       Nn                1c    Tfin      1c   
  Tfin     1c    | 
| 39 | 1, 38 | syl5bi 208 | 
. 2
       Nn         1c        Tfin   
 
1c 
    Tfin     1c    | 
| 40 | 39 | imp 418 | 
1
        Nn        1c         Tfin   
 
1c 
    Tfin     1c   |