Proof of Theorem hmph
| Step | Hyp | Ref
| Expression |
| 1 | | eleq1 1526 |
. . . 4
  Top Top  |
| 2 | | opreq1 3953 |
. . . . . 6
  Homeo   Homeo    |
| 3 | 2 | eleq2d 1533 |
. . . . 5
   Homeo   Homeo     |
| 4 | 3 | exbidv 1274 |
. . . 4
    Homeo    Homeo     |
| 5 | 1, 4 | 3anbi13d 892 |
. . 3
   Top Top   Homeo    Top Top   Homeo      |
| 6 | | eleq1 1526 |
. . . . . 6
  Top Top  |
| 7 | 6 | bicomd 519 |
. . . . 5
  Top Top  |
| 8 | | opreq2 3954 |
. . . . . . . 8
  Homeo   Homeo    |
| 9 | 8 | eqcoms 1470 |
. . . . . . 7
  Homeo   Homeo    |
| 10 | 9 | eleq2d 1533 |
. . . . . 6
   Homeo   Homeo     |
| 11 | 10 | exbidv 1274 |
. . . . 5
    Homeo    Homeo     |
| 12 | 7, 11 | 3anbi23d 893 |
. . . 4
   Top
Top   Homeo    Top Top
  Homeo      |
| 13 | | df-3an 775 |
. . . 4
  Top Top
  Homeo     Top
Top   Homeo     |
| 14 | 12, 13 | syl5rbbr 533 |
. . 3
   Top Top   Homeo     Top Top   Homeo      |
| 15 | | df-hmph 10410 |
. . 3
~=      Top Top   Homeo     |
| 16 | 5, 14, 15 | brabg 2807 |
. 2
  Top
Top  ~=
  Top Top
  Homeo      |
| 17 | 16 | bianabs 651 |
1
  Top
Top  ~=
  Homeo     |