Step |
Hyp |
Ref |
Expression |
1 |
|
erclwwlkn.w |
|
2 |
|
erclwwlkn.r |
|
3 |
|
elqsecl |
|
4 |
1 2
|
erclwwlknsym |
|
5 |
1 2
|
erclwwlknsym |
|
6 |
4 5
|
impbii |
|
7 |
6
|
a1i |
|
8 |
7
|
abbidv |
|
9 |
1 2
|
erclwwlkneq |
|
10 |
9
|
el2v |
|
11 |
10
|
a1i |
|
12 |
11
|
abbidv |
|
13 |
|
3anan12 |
|
14 |
|
ibar |
|
15 |
14
|
bicomd |
|
16 |
15
|
adantl |
|
17 |
13 16
|
syl5bb |
|
18 |
17
|
abbidv |
|
19 |
|
df-rab |
|
20 |
18 19
|
eqtr4di |
|
21 |
8 12 20
|
3eqtrd |
|
22 |
21
|
eqeq2d |
|
23 |
22
|
rexbidva |
|
24 |
3 23
|
bitrd |
|