Proof of Theorem hhsssh
| Step | Hyp | Ref
| Expression |
| 1 | | hhsst.1 |
. . . 4
    |
| 2 | | hhsst.2 |
. . . 4
      
        |
| 3 | 1, 2 | hhsst 9056 |
. . 3

SubSp    |
| 4 | | shss 9000 |
. . 3

  |
| 5 | 3, 4 | jca 288 |
. 2

 SubSp     |
| 6 | | eleq1 1526 |
. . 3
    SubSp     

   SubSp     
   |
| 7 | | eqid 1468 |
. . . 4
 
    SubSp     
   SubSp         
   SubSp              SubSp              SubSp 
 
     SubSp         
   SubSp              SubSp         |
| 8 | | xpeq1 3190 |
. . . . . . . . . . . . 13
    SubSp     
      SubSp 
 
     |
| 9 | | xpeq2 3191 |
. . . . . . . . . . . . 13
    SubSp     
    SubSp     
     SubSp     
   SubSp         |
| 10 | 8, 9 | eqtrd 1499 |
. . . . . . . . . . . 12
    SubSp     
      SubSp 
 
     SubSp         |
| 11 | | reseq2 3353 |
. . . . . . . . . . . 12
       SubSp     
   SubSp              SubSp 
 
     SubSp          |
| 12 | 10, 11 | syl 10 |
. . . . . . . . . . 11
    SubSp     
  
    SubSp     
   SubSp          |
| 13 | | xpeq2 3191 |
. . . . . . . . . . . 12
    SubSp     
      SubSp         |
| 14 | | reseq2 3353 |
. . . . . . . . . . . 12
       SubSp       
      SubSp 
 
      |
| 15 | 13, 14 | syl 10 |
. . . . . . . . . . 11
    SubSp     
  
    SubSp 
 
      |
| 16 | 12, 15 | opeq12d 2486 |
. . . . . . . . . 10
    SubSp     
     
   
    SubSp     
   SubSp         
   SubSp           |
| 17 | | reseq2 3353 |
. . . . . . . . . 10
    SubSp     
      SubSp         |
| 18 | 16, 17 | opeq12d 2486 |
. . . . . . . . 9
    SubSp     
      
             SubSp     
   SubSp         
   SubSp              SubSp          |
| 19 | 18, 2 | syl5eq 1511 |
. . . . . . . 8
    SubSp     
      SubSp 
 
     SubSp         
   SubSp              SubSp          |
| 20 | 19 | eleq1d 1532 |
. . . . . . 7
    SubSp     
 SubSp   
    SubSp 
 
     SubSp         
   SubSp              SubSp        SubSp     |
| 21 | | sseq1 2072 |
. . . . . . 7
    SubSp     
    SubSp         |
| 22 | 20, 21 | anbi12d 626 |
. . . . . 6
    SubSp     
  SubSp     
    SubSp 
 
     SubSp         
   SubSp              SubSp        SubSp     SubSp 
 
      |
| 23 | | xpeq1 3190 |
. . . . . . . . . . . 12

   SubSp     
      SubSp 
 
     |
| 24 | | xpeq2 3191 |
. . . . . . . . . . . 12

   SubSp     
    SubSp     
     SubSp     
   SubSp         |
| 25 | 23, 24 | eqtrd 1499 |
. . . . . . . . . . 11

   SubSp     
      SubSp 
 
     SubSp         |
| 26 | | reseq2 3353 |
. . . . . . . . . . 11
       SubSp     
   SubSp              SubSp 
 
     SubSp       ![]() |