Proof of Theorem rankuni
| Step | Hyp | Ref
| Expression |
| 1 | | unieq 3185 |
. . . . 5
     |
| 2 | 1 | fveq2d 4685 |
. . . 4
             |
| 3 | | fveq2 4681 |
. . . . 5
           |
| 4 | 3 | unieqd 3188 |
. . . 4
             |
| 5 | 2, 4 | eqeq12d 1899 |
. . 3
                         |
| 6 | | visset 2295 |
. . . . . . 7
 |
| 7 | 6 | rankuni2 5801 |
. . . . . 6
           |
| 8 | | fvex 4689 |
. . . . . . 7
     |
| 9 | 8 | dfiun2 3285 |
. . . . . 6

      
      |
| 10 | 7, 9 | eqtri 1908 |
. . . . 5
              |
| 11 | | df-rex 2110 |
. . . . . . . 8
                |
| 12 | 6 | rankel 5791 |
. . . . . . . . . . 11
           |
| 13 | 12 | anim1i 361 |
. . . . . . . . . 10
                       |
| 14 | 13 | eximi 1387 |
. . . . . . . . 9
                           |
| 15 | | 19.42v 1688 |
. . . . . . . . . 10
                          |
| 16 | | eleq1 1957 |
. . . . . . . . . . . 12
                     |
| 17 | 16 | pm5.32ri 708 |
. . . . . . . . . . 11
                   
       |
| 18 | 17 | exbii 1398 |
. . . . . . . . . 10
                       
       |
| 19 | | simpl 346 |
. . . . . . . . . . 11
                  |
| 20 | | rankon 5782 |
. . . . . . . . . . . . . . . 16
     |
| 21 | 20 | oneli 3777 |
. . . . . . . . . . . . . . 15
       |
| 22 | | rankr1id 5808 |
. . . . . . . . . . . . . . 15
           |
| 23 | 21, 22 | sylib 215 |
. . . . . . . . . . . . . 14
               |
| 24 | 23 | eqcomd 1889 |
. . . . . . . . . . . . 13
               |
| 25 | | fvex 4689 |
. . . . . . . . . . . . . 14
     |
| 26 | | fveq2 4681 |
. . . . . . . . . . . . . . 15
                   |
| 27 | 26 | eqeq2d 1895 |
. . . . . . . . . . . . . 14
                     |
| 28 | 25, 27 | cla4ev 2371 |
. . . . . . . . . . . . 13
                |
| 29 | 24, 28 | syl 12 |
. . . . . . . . . . . 12
            |
| 30 | 29 | ancli 320 |
. . . . . . . . . . 11
                  |
| 31 | 19, 30 | impbii 174 |
. . . . . . . . . 10
                  |
| 32 | 15, 18, 31 | 3bitr3i 198 |
. . . . . . . . 9
                       |
| 33 | 14, 32 | sylib 215 |
. . . . . . . 8
               |
| 34 | 11, 33 | sylbi 216 |
. . . . . . 7
            |
| 35 | 34 | abssi 2682 |
. . . . . 6
            |
| 36 | | uniss 3199 |
. . . . . 6
  
                        |
| 37 | 35, 36 | ax-mp 7 |
. . . . 5
              |
| 38 | 10, 37 | eqsstri 2647 |
. . . 4
           |
| 39 | | pwuni 3505 |
. . . . . . . 8
   |
| 40 | 6 | uniex 3794 |
. . . . . . . . . 10
  |
| 41 | 40 | pwex 3487 |
. . . . . . . . 9
 
 |
| 42 | 41 | rankss 5799 |
. . . . . . . 8
               |
| 43 | 39, 42 | ax-mp 7 |
. . . . . . 7
           |
| 44 | 40 | rankpw 5795 |
. . . . . . 7
            |
| 45 | 43, 44 | sseqtri 2649 |
. . . . . 6
          |
| 46 | | uniss 3199 |
. . . . . 6
               
       |
| 47 | 45, 46 | ax-mp 7 |
. . . . 5
     
      |
| 48 | | rankon 5782 |
. . . . . 6
      |
| 49 | 48 | onunisuci 3783 |
. . . . 5
            |
| 50 | 47, 49 | sseqtri 2649 |
. . . 4
           |
| 51 | 38, 50 | eqssi 2632 |
. . 3
           |
| 52 | 5, 51 | vtoclg 2346 |
. 2

            |
| 53 | | uniexb 3851 |
. . . . . 6

   |
| 54 | 53 | notbii 204 |
. . . . 5

   |
| 55 | | fvprc 4678 |
. . . . 5
         |
| 56 | 54, 55 | sylbi 216 |
. . . 4

       |
| 57 | | uni0 3205 |
. . . 4
  |
| 58 | 56, 57 | syl6eqr 1946 |
. . 3

        |
| 59 | | fvprc 4678 |
. . . 4

      |
| 60 | 59 | unieqd 3188 |
. . 3

        |
| 61 | 58, 60 | eqtr4d 1928 |
. 2

            |
| 62 | 52, 61 | pm2.61i 140 |
1
           |