Proof of Theorem subtopsin2
| Step | Hyp | Ref
| Expression |
| 1 | | simpl 346 |
. . . . 5
  Top

Top |
| 2 | | visset 2295 |
. . . . . 6
 |
| 3 | 2 | a1i 8 |
. . . . 5
  Top

  |
| 4 | | snex 3492 |
. . . . . 6
 
 |
| 5 | 4 | a1i 8 |
. . . . 5
  Top
     |
| 6 | | issubspt 10247 |
. . . . 5
  Top
   
subSp               |
| 7 | 1, 3, 5, 6 | syl111anc 1100 |
. . . 4
  Top
  subSp               |
| 8 | | snssi 3129 |
. . . . . . . 8

    |
| 9 | | df-ss 2605 |
. . . . . . . . 9
           |
| 10 | | incom 2787 |
. . . . . . . . . 10
         |
| 11 | | eqtr 1904 |
. . . . . . . . . . . . 13
                 |
| 12 | | olc 290 |
. . . . . . . . . . . . . 14
  
      |
| 13 | 2 | elpr 3061 |
. . . . . . . . . . . . . 14

     
     |
| 14 | 12, 13 | sylibr 217 |
. . . . . . . . . . . . 13
  
       |
| 15 | 11, 14 | syl 12 |
. . . . . . . . . . . 12
                    |
| 16 | 15 | ex 402 |
. . . . . . . . . . 11
           
        |
| 17 | | eqtr 1904 |
. . . . . . . . . . 11
        
   
            |
| 18 | 16, 17 | syl5com 63 |
. . . . . . . . . 10
        
   
                 |
| 19 | 10, 18 | mpan 759 |
. . . . . . . . 9
                    |
| 20 | 9, 19 | sylbi 216 |
. . . . . . . 8
  
             |
| 21 | 8, 20 | syl 12 |
. . . . . . 7

             |
| 22 | | disjsn 3089 |
. . . . . . . 8
    
  |
| 23 | | eqtr 1904 |
. . . . . . . . . 10
          
  |
| 24 | | orc 291 |
. . . . . . . . . . 11
 
     |
| 25 | 24, 13 | sylibr 217 |
. . . . . . . . . 10

       |
| 26 | 23, 25 | syl 12 |
. . . . . . . . 9
          
       |
| 27 | 26 | expcom 403 |
. . . . . . . 8
                  |
| 28 | 22, 27 | sylbir 218 |
. . . . . . 7

             |
| 29 | 21, 28 | pm2.61i 140 |
. . . . . 6
            |
| 30 | 29 | a1i 8 |
. . . . 5
              |
| 31 | 30 | r19.23aiv 2211 |
. . . 4
             |
| 32 | 7, 31 | syl6bi 231 |
. . 3
  Top
  subSp      
        |
| 33 | | eleq1 1957 |
. . . . . . 7
  subSp       subSp          |
| 34 | | stoig 10251 |
. . . . . . . . 9
  Top         subSp    
   TopSp |
| 35 | | subtopsin2.1 |
. . . . . . . . . . 11
  |
| 36 | 35 | eleq2i 1961 |
. . . . . . . . . 10

   |
| 37 | | snssi 3129 |
. . . . . . . . . 10

      |
| 38 | 36, 37 | sylbi 216 |
. . . . . . . . 9

     |
| 39 | 34, 38 | sylan2 500 |
. . . . . . . 8
  Top
     subSp    
   TopSp |
| 40 | | istps 8875 |
. . . . . . . . 9
     subSp    
   TopSp  subSp       Top    subSp          |
| 41 | | 0opn 8870 |
. . . . . . . . . 10
 subSp    
  Top
subSp    
    |
| 42 | 41 | adantr 425 |
. . . . . . . . 9
  subSp       Top    subSp    
   subSp    
    |
| 43 | 40, 42 | sylbi 216 |
. . . . . . . 8
     subSp    
   TopSp subSp    
    |
| 44 | 39, 43 | syl 12 |
. . . . . . 7
  Top
 subSp         |
| 45 | 33, 44 | syl5bir 227 |
. . . . . 6
   Top

subSp    
     |
| 46 | | eleq1 1957 |
. . . . . . 7
  
 subSp    
    subSp    
     |
| 47 | | eqid 1884 |
. . . . . . . . . . 11
 subSp        subSp    
   |
| 48 | 47 | topopn 8871 |
. . . . . . . . . 10
 subSp    
  Top
 subSp       subSp         |
| 49 | | eleq1 1957 |
. . . . . . . . . . . 12
  subSp    
   
  subSp    
 
subSp        
subSp          |
| 50 | 49 | biimpd 170 |
. . . . . . . . . . 11
  subSp    
   
  subSp    
 
subSp        
subSp          |
| 51 | 50 | eqcoms 1887 |
. . . . . . . . . 10
    subSp    
 
  subSp    
 
subSp        
subSp          |
| 52 | 48, 51 | mpan9 521 |
. . . . . . . . 9
  subSp       Top    subSp    
    
subSp         |
| 53 | 40, 52 | sylbi 216 |
. . . . . . . 8
     subSp    
   TopSp  
subSp         |
| 54 | 39, 53 | syl 12 |
. . . . . . 7
  Top
   subSp    
    |
| 55 | 46, 54 | syl5bir 227 |
. . . . . 6
  
  Top  subSp    
     |
| 56 | 45, 55 | jaoi 368 |
. . . . 5
 
     Top

subSp          |
| 57 | 13, 56 | sylbi 216 |
. . . 4

       Top

subSp          |
| 58 | 57 | com12 14 |
. . 3
  Top
      
subSp    
     |
| 59 | 32, 58 | impbid 574 |
. 2
  Top
  subSp      
        |
| 60 | 59 | eqrdv 1882 |
1
  Top
 subSp    
         |