Step |
Hyp |
Ref |
Expression |
1 |
|
dfdif2 |
|
2 |
|
ax6ev |
|
3 |
2
|
biantrur |
|
4 |
|
19.41v |
|
5 |
3 4
|
bitr4i |
|
6 |
|
sb56 |
|
7 |
|
equcom |
|
8 |
7
|
imbi1i |
|
9 |
|
eleq1w |
|
10 |
9
|
notbid |
|
11 |
10
|
pm5.74i |
|
12 |
|
con2b |
|
13 |
|
df-ne |
|
14 |
13
|
bicomi |
|
15 |
14
|
imbi2i |
|
16 |
11 12 15
|
3bitri |
|
17 |
8 16
|
bitri |
|
18 |
17
|
albii |
|
19 |
5 6 18
|
3bitri |
|
20 |
|
df-ral |
|
21 |
19 20
|
bitr4i |
|
22 |
21
|
rabbii |
|
23 |
1 22
|
eqtri |
|