Step |
Hyp |
Ref |
Expression |
1 |
|
braew.1 |
|
2 |
|
dmexg |
|
3 |
2
|
uniexd |
|
4 |
1 3
|
eqeltrrid |
|
5 |
|
rabexg |
|
6 |
4 5
|
syl |
|
7 |
|
simpr |
|
8 |
7
|
dmeqd |
|
9 |
8
|
unieqd |
|
10 |
|
simpl |
|
11 |
9 10
|
difeq12d |
|
12 |
7 11
|
fveq12d |
|
13 |
12
|
eqeq1d |
|
14 |
|
df-ae |
|
15 |
13 14
|
brabga |
|
16 |
6 15
|
mpancom |
|
17 |
1
|
difeq1i |
|
18 |
|
notrab |
|
19 |
17 18
|
eqtri |
|
20 |
19
|
fveq2i |
|
21 |
20
|
eqeq1i |
|
22 |
16 21
|
syl6bb |
|