| Step | Hyp | Ref
 | Expression | 
| 1 |   | simp2 956 | 
. . . 4
        NC         Spac
        
↑c 0c    NC           Spac
     | 
| 2 |   | spacval 6283 | 
. . . . 5
       NC     Spac    
   Clos1                      NC       NC        2c ↑c
       | 
| 3 | 2 | 3ad2ant1 976 | 
. . . 4
        NC         Spac
        
↑c 0c    NC       Spac       
Clos1      
               NC       NC        2c ↑c
       | 
| 4 | 1, 3 | eleqtrd 2429 | 
. . 3
        NC         Spac
        
↑c 0c    NC         
Clos1      
               NC       NC        2c ↑c
       | 
| 5 |   | spacssnc 6285 | 
. . . . . 6
       NC     Spac    
  NC   | 
| 6 | 5 | sselda 3274 | 
. . . . 5
        NC         Spac
           NC   | 
| 7 | 6 | 3adant3 975 | 
. . . 4
        NC         Spac
        
↑c 0c    NC         NC   | 
| 8 |   | simp3 957 | 
. . . . 5
        NC         Spac
        
↑c 0c    NC        ↑c
0c 
  NC   | 
| 9 |   | 2nnc 6168 | 
. . . . . 6
 
2c  
Nn | 
| 10 |   | ceclnn1 6190 | 
. . . . . 6
    2c   Nn       NC     
↑c 0c    NC      2c ↑c     
NC   | 
| 11 | 9, 10 | mp3an1 1264 | 
. . . . 5
        NC      ↑c
0c 
  NC      2c
↑c      NC   | 
| 12 | 7, 8, 11 | syl2anc 642 | 
. . . 4
        NC         Spac
        
↑c 0c    NC      2c ↑c     
NC   | 
| 13 |   | eqidd 2354 | 
. . . 4
        NC         Spac
        
↑c 0c    NC      2c ↑c     
 2c
↑c     | 
| 14 |   | ovex 5552 | 
. . . . . 6
   2c
↑c        | 
| 15 |   | eleq1 2413 | 
. . . . . . . 8
               
NC      
NC    | 
| 16 |   | oveq2 5532 | 
. . . . . . . . 9
            2c
↑c       2c ↑c
    | 
| 17 | 16 | eqeq2d 2364 | 
. . . . . . . 8
               
 2c
↑c           2c ↑c      | 
| 18 | 15, 17 | 3anbi13d 1254 | 
. . . . . . 7
              
  NC       NC        2c ↑c
           NC       NC        2c ↑c
      | 
| 19 |   | eleq1 2413 | 
. . . . . . . 8
        2c ↑c           NC    2c
↑c      NC    | 
| 20 |   | eqeq1 2359 | 
. . . . . . . 8
        2c ↑c            2c ↑c       2c ↑c     
 2c
↑c      | 
| 21 | 19, 20 | 3anbi23d 1255 | 
. . . . . . 7
        2c ↑c            NC       NC        2c ↑c
           NC    2c ↑c     
NC    2c ↑c     
 2c
↑c       | 
| 22 |   | eqid 2353 | 
. . . . . . 7
      
          NC       NC        2c ↑c
           
          NC       NC        2c ↑c
     | 
| 23 | 18, 21, 22 | brabg 4707 | 
. . . . . 6
          Spac        2c
↑c                            NC       NC        2c ↑c
      2c ↑c           NC    2c ↑c     
NC    2c ↑c     
 2c
↑c       | 
| 24 | 14, 23 | mpan2 652 | 
. . . . 5
         Spac                        NC       NC        2c ↑c
      2c ↑c           NC    2c ↑c     
NC    2c ↑c     
 2c
↑c       | 
| 25 | 24 | 3ad2ant2 977 | 
. . . 4
        NC         Spac
        
↑c 0c    NC                      NC       NC        2c ↑c
      2c ↑c           NC    2c ↑c     
NC    2c ↑c     
 2c
↑c       | 
| 26 | 7, 12, 13, 25 | mpbir3and 1135 | 
. . 3
        NC         Spac
        
↑c 0c    NC          
          NC       NC        2c ↑c
      2c ↑c     | 
| 27 |   | eqid 2353 | 
. . . 4
   Clos1                      NC       NC        2c ↑c
        
Clos1      
               NC       NC        2c ↑c
      | 
| 28 | 27 | clos1conn 5880 | 
. . 3
         Clos1                      NC       NC        2c ↑c
                        NC       NC      
 2c
↑c       2c ↑c        2c
↑c      
Clos1      
               NC       NC        2c ↑c
       | 
| 29 | 4, 26, 28 | syl2anc 642 | 
. 2
        NC         Spac
        
↑c 0c    NC      2c ↑c     
 Clos1                      NC       NC      
 2c
↑c        | 
| 30 | 29, 3 | eleqtrrd 2430 | 
1
        NC         Spac
        
↑c 0c    NC      2c ↑c     
  Spac      |