Proof of Theorem singcon
| Step | Hyp | Ref
| Expression |
| 1 | | singcon.1 |
. . . . . 6
  |
| 2 | 1 | subtopsin2 14907 |
. . . . 5
  Top
 subSp    
         |
| 3 | | stoig2 10252 |
. . . . . . . 8
  Top      subSp    
      |
| 4 | 3 | eqcomd 1889 |
. . . . . . 7
  Top        subSp    
    |
| 5 | | snssg 3124 |
. . . . . . . . 9

        |
| 6 | 1 | eleq2i 1961 |
. . . . . . . . 9

   |
| 7 | 5, 6 | syl5bb 591 |
. . . . . . . 8

       |
| 8 | 7 | ibi 652 |
. . . . . . 7

     |
| 9 | 4, 8 | sylan2 500 |
. . . . . 6
  Top
    subSp    
    |
| 10 | | preq2 3099 |
. . . . . 6
    subSp    
 
        subSp          |
| 11 | 9, 10 | syl 12 |
. . . . 5
  Top
         subSp          |
| 12 | 2, 11 | eqtrd 1925 |
. . . 4
  Top
 subSp    
     subSp          |
| 13 | 2 | fveq2d 4685 |
. . . . 5
  Top
 Clsd subSp        Clsd         |
| 14 | | snex 3492 |
. . . . . . 7
 
 |
| 15 | 14 | clindistop 14962 |
. . . . . 6
Clsd             |
| 16 | 15 | a1i 8 |
. . . . 5
  Top
 Clsd              |
| 17 | 3, 8 | sylan2 500 |
. . . . . . 7
  Top
  subSp           |
| 18 | 17 | eqcomd 1889 |
. . . . . 6
  Top
    subSp    
    |
| 19 | 18, 10 | syl 12 |
. . . . 5
  Top
         subSp          |
| 20 | 13, 16, 19 | 3eqtrd 1929 |
. . . 4
  Top
 Clsd subSp           subSp    
     |
| 21 | 12, 20 | ineq12d 2797 |
. . 3
  Top
  subSp       Clsd subSp    
        subSp    
  
   subSp           |
| 22 | | inidm 2803 |
. . 3
    subSp           subSp            subSp    
    |
| 23 | 21, 22 | syl6eq 1944 |
. 2
  Top
  subSp       Clsd subSp    
       subSp    
     |
| 24 | | stoig3 10253 |
. . . 4
  Top     subSp    
 
Top |
| 25 | 24, 8 | sylan2 500 |
. . 3
  Top
 subSp    
 
Top |
| 26 | | iscon 10339 |
. . 3
 subSp    
  Top
 subSp    
  Con
 subSp       Clsd subSp            subSp    
      |
| 27 | 25, 26 | syl 12 |
. 2
  Top
  subSp       Con  subSp       Clsd subSp            subSp    
      |
| 28 | 23, 27 | mpbird 213 |
1
  Top
 subSp    
 
Con |