Proof of Theorem cnss
| Step | Hyp | Ref
| Expression |
| 1 | | stoig2 10252 |
. . . . . . . 8
  Top    subSp       |
| 2 | | cnss.1 |
. . . . . . . . 9
  |
| 3 | 2 | sseq2i 2642 |
. . . . . . . 8
    |
| 4 | 1, 3 | sylan2b 501 |
. . . . . . 7
  Top   subSp       |
| 5 | 4 | adantll 428 |
. . . . . 6
   Top
Top
  subSp       |
| 6 | | feq3 4553 |
. . . . . 6
  subSp            subSp             |
| 7 | 5, 6 | syl 12 |
. . . . 5
   Top
Top
        subSp             |
| 8 | 7 | anbi1d 679 |
. . . 4
   Top
Top
         subSp    
 subSp                  
subSp  
            |
| 9 | | fss 4571 |
. . . . . . . 8
               |
| 10 | 9 | expcom 403 |
. . . . . . 7
               |
| 11 | 10 | adantrd 427 |
. . . . . 6
        
subSp  
                 |
| 12 | 11 | adantl 424 |
. . . . 5
   Top
Top
         subSp                    |
| 13 | | ffun 4565 |
. . . . . . . . . . . 12
        |
| 14 | 13 | adantr 425 |
. . . . . . . . . . 11
       
subSp  
           |
| 15 | 14 | ad2antlr 441 |
. . . . . . . . . 10
     Top Top
        subSp                |
| 16 | | inpreima 15682 |
. . . . . . . . . 10

    
       
        |
| 17 | 15, 16 | syl 12 |
. . . . . . . . 9
     Top Top
        subSp                  
       
        |
| 18 | | imassrn 4278 |
. . . . . . . . . . . . . . 15
      |
| 19 | 18 | a1i 8 |
. . . . . . . . . . . . . 14
          
  |
| 20 | | fdm 4567 |
. . . . . . . . . . . . . . 15
         |
| 21 | | dfdm4 4151 |
. . . . . . . . . . . . . . 15
 |
| 22 | 20, 21 | syl5eqr 1942 |
. . . . . . . . . . . . . 14
         |
| 23 | 19, 22 | sseqtrd 2653 |
. . . . . . . . . . . . 13
              |
| 24 | | fimacnv 4783 |
. . . . . . . . . . . . 13
              |
| 25 | 23, 24 | sseqtr4d 2654 |
. . . . . . . . . . . 12
                  |
| 26 | 25 | adantr 425 |
. . . . . . . . . . 11
       
subSp  
                     |
| 27 | 26 | ad2antlr 441 |
. . . . . . . . . 10
     Top Top
        subSp                          |
| 28 | | df-ss 2605 |
. . . . . . . . . 10
                              |
| 29 | 27, 28 | sylib 215 |
. . . . . . . . 9
     Top Top
        subSp                                 |
| 30 | 17, 29 | eqtr2d 1926 |
. . . . . . . 8
     Top Top
        subSp                            |
| 31 | | imaeq2 4260 |
. . . . . . . . . . . . 13
            
    |
| 32 | 31 | eleq1d 1963 |
. . . . . . . . . . . 12
                   |
| 33 | 32 | rcla4va 2378 |
. . . . . . . . . . 11
    subSp    
 subSp                     |
| 34 | | eqid 1884 |
. . . . . . . . . . . . . . 15

    |
| 35 | | ineq1 2789 |
. . . . . . . . . . . . . . . . 17
       |
| 36 | 35 | eqeq2d 1895 |
. . . . . . . . . . . . . . . 16
             |
| 37 | 36 | rcla4ev 2381 |
. . . . . . . . . . . . . . 15
              |
| 38 | 34, 37 | mpan2 760 |
. . . . . . . . . . . . . 14

       |
| 39 | 38 | adantl 424 |
. . . . . . . . . . . . 13
   Top
         |
| 40 | | ssexg 3457 |
. . . . . . . . . . . . . . . . 17
 

  |
| 41 | | uniexg 3795 |
. . . . . . . . . . . . . . . . . 18
 Top
   |
| 42 | 41, 2 | syl5eqel 1975 |
. . . . . . . . . . . . . . . . 17
 Top
  |
| 43 | 40, 42 | sylan2 500 |
. . . . . . . . . . . . . . . 16
 
Top
  |
| 44 | 43 | ancoms 484 |
. . . . . . . . . . . . . . 15
  Top    |
| 45 | | visset 2295 |
. . . . . . . . . . . . . . . . 17
 |
| 46 | 45 | inex1 3452 |
. . . . . . . . . . . . . . . 16

  |
| 47 | | issubspt 10247 |
. . . . . . . . . . . . . . . 16
  Top  
    subSp    

       |
| 48 | 46, 47 | mp3an2 1179 |
. . . . . . . . . . . . . . 15
  Top
    subSp    

       |
| 49 | 44, 48 | syldan 516 |
. . . . . . . . . . . . . 14
  Top     subSp    

       |
| 50 | 49 | adantr 425 |
. . . . . . . . . . . . 13
   Top
     subSp  
          |
| 51 | 39, 50 | mpbird 213 |
. . . . . . . . . . . 12
   Top
    subSp       |
| 52 | 51 | adantlll 432 |
. . . . . . . . . . 11
    Top Top   
 subSp       |
| 53 | 33, 52 | sylan 497 |
. . . . . . . . . 10
     Top Top
  
subSp  
             
    |
| 54 | 53 | an1rs 547 |
. . . . . . . . 9
     Top Top
 
subSp  
              
    |
| 55 | 54 | adantlrl 434 |
. . . . . . . 8
     Top Top
        subSp                  
    |
| 56 | 30, 55 | eqeltrd 1971 |
. . . . . . 7
     Top Top
        subSp                  
  |
| 57 | 56 | r19.21aiva 2176 |
. . . . . 6
    Top Top         subSp             
       |
| 58 | 57 | ex 402 |
. . . . 5
   Top
Top
         subSp            
    
   |
| 59 | 12, 58 | jcad 661 |
. . . 4
   Top
Top
         subSp                  
         |
| 60 | 8, 59 | sylbid 220 |
. . 3
   Top
Top
         subSp    
 subSp                            |
| 61 | | eqid 1884 |
. . . . . 6
   |
| 62 | | eqid 1884 |
. . . . . 6
 subSp      subSp      |
| 63 | 61, 62 | iscn 9034 |
. . . . 5
  Top subSp     Top   Cn subSp             subSp    
 subSp               |
| 64 | | stoig3 10253 |
. . . . . 6
  Top   subSp  
 
Top |
| 65 | 64, 3 | sylan2b 501 |
. . . . 5
  Top  subSp     Top |
| 66 | 63, 65 | sylan2 500 |
. . . 4
  Top  Top     Cn subSp             subSp    
 subSp               |
| 67 | 66 | anassrs 489 |
. . 3
   Top
Top
   Cn subSp             subSp    
 subSp               |
| 68 | 61, 2 | iscn 9034 |
. . . 4
  Top
Top   Cn        
         |
| 69 | 68 | adantr 425 |
. . 3
   Top
Top
   Cn        
    
    |
| 70 | 60, 67, 69 | 3imtr4d 602 |
. 2
   Top
Top
   Cn subSp       Cn     |
| 71 | 70 | impr 422 |
1
   Top
Top 
 Cn
subSp  
      Cn    |