| Step | Hyp | Ref
| Expression |
| 1 | | setscomd.ab |
. 2
   |
| 2 | | setscomd.b |
. . 3
   |
| 3 | | simpr 110 |
. . . . 5
 
   |
| 4 | 3 | neeq2d 2386 |
. . . 4
 
 
   |
| 5 | 3 | opeq1d 3815 |
. . . . . 6
 
   
     |
| 6 | 5 | oveq2d 5941 |
. . . . 5
 
   sSet
    sSet       sSet     sSet       |
| 7 | 5 | oveq2d 5941 |
. . . . . 6
 
  sSet      sSet       |
| 8 | 7 | oveq1d 5940 |
. . . . 5
 
   sSet
    sSet       sSet     sSet       |
| 9 | 6, 8 | eqeq12d 2211 |
. . . 4
 
    sSet     sSet       sSet     sSet       sSet     sSet  
    sSet     sSet        |
| 10 | 4, 9 | imbi12d 234 |
. . 3
 
     sSet     sSet       sSet     sSet      
  sSet     sSet       sSet     sSet         |
| 11 | | setscomd.a |
. . . 4
   |
| 12 | | simpr 110 |
. . . . . 6
 
   |
| 13 | 12 | neeq1d 2385 |
. . . . 5
 
 
   |
| 14 | 12 | opeq1d 3815 |
. . . . . . . 8
 
   
     |
| 15 | 14 | oveq2d 5941 |
. . . . . . 7
 
  sSet      sSet       |
| 16 | 15 | oveq1d 5940 |
. . . . . 6
 
   sSet
    sSet       sSet     sSet       |
| 17 | 14 | oveq2d 5941 |
. . . . . 6
 
   sSet
    sSet       sSet     sSet       |
| 18 | 16, 17 | eqeq12d 2211 |
. . . . 5
 
    sSet     sSet       sSet     sSet       sSet     sSet       sSet     sSet        |
| 19 | 13, 18 | imbi12d 234 |
. . . 4
 
     sSet     sSet       sSet     sSet      
  sSet     sSet       sSet     sSet         |
| 20 | | setscomd.s |
. . . . . . 7
   |
| 21 | 20 | adantr 276 |
. . . . . 6
 
   |
| 22 | | simpr 110 |
. . . . . 6
 
   |
| 23 | | setscomd.c |
. . . . . . 7
   |
| 24 | 23 | adantr 276 |
. . . . . 6
 
   |
| 25 | | setscomd.d |
. . . . . . 7
   |
| 26 | 25 | adantr 276 |
. . . . . 6
 
   |
| 27 | | vex 2766 |
. . . . . . 7
 |
| 28 | | vex 2766 |
. . . . . . 7
 |
| 29 | 27, 28 | setscom 12743 |
. . . . . 6
  


    sSet     sSet       sSet     sSet       |
| 30 | 21, 22, 24, 26, 29 | syl22anc 1250 |
. . . . 5
 
   sSet
    sSet       sSet     sSet       |
| 31 | 30 | ex 115 |
. . . 4
    sSet     sSet       sSet     sSet        |
| 32 | 11, 19, 31 | vtocld 2816 |
. . 3
    sSet     sSet       sSet     sSet        |
| 33 | 2, 10, 32 | vtocld 2816 |
. 2
    sSet     sSet  
    sSet     sSet        |
| 34 | 1, 33 | mpd 13 |
1
   sSet     sSet  
    sSet     sSet       |