| Step |
Hyp |
Ref |
Expression |
| 1 |
|
dftr6.1 |
|
| 2 |
1
|
elrn |
|
| 3 |
|
brdif |
|
| 4 |
|
vex |
|
| 5 |
4 1
|
brco |
|
| 6 |
|
epel |
|
| 7 |
1
|
epeli |
|
| 8 |
6 7
|
anbi12i |
|
| 9 |
8
|
exbii |
|
| 10 |
5 9
|
bitri |
|
| 11 |
1
|
epeli |
|
| 12 |
11
|
notbii |
|
| 13 |
10 12
|
anbi12i |
|
| 14 |
|
19.41v |
|
| 15 |
|
exanali |
|
| 16 |
14 15
|
bitr3i |
|
| 17 |
3 13 16
|
3bitri |
|
| 18 |
17
|
exbii |
|
| 19 |
|
exnal |
|
| 20 |
2 18 19
|
3bitri |
|
| 21 |
20
|
con2bii |
|
| 22 |
|
dftr2 |
|
| 23 |
|
eldif |
|
| 24 |
1 23
|
mpbiran |
|
| 25 |
21 22 24
|
3bitr4i |
|