Step |
Hyp |
Ref |
Expression |
1 |
|
idffth.i |
|
2 |
|
relfunc |
|
3 |
1
|
idfucl |
|
4 |
|
1st2nd |
|
5 |
2 3 4
|
sylancr |
|
6 |
5 3
|
eqeltrrd |
|
7 |
|
df-br |
|
8 |
6 7
|
sylibr |
|
9 |
|
f1oi |
|
10 |
|
eqid |
|
11 |
|
simpl |
|
12 |
|
eqid |
|
13 |
|
simprl |
|
14 |
|
simprr |
|
15 |
1 10 11 12 13 14
|
idfu2nd |
|
16 |
|
eqidd |
|
17 |
1 10 11 13
|
idfu1 |
|
18 |
1 10 11 14
|
idfu1 |
|
19 |
17 18
|
oveq12d |
|
20 |
15 16 19
|
f1oeq123d |
|
21 |
9 20
|
mpbiri |
|
22 |
21
|
ralrimivva |
|
23 |
10 12 12
|
isffth2 |
|
24 |
8 22 23
|
sylanbrc |
|
25 |
|
df-br |
|
26 |
24 25
|
sylib |
|
27 |
5 26
|
eqeltrd |
|