Step |
Hyp |
Ref |
Expression |
1 |
|
brtxpsd.1 |
|
2 |
|
brtxpsd.2 |
|
3 |
|
df-br |
|
4 |
|
opex |
|
5 |
4
|
elrn |
|
6 |
|
brsymdif |
|
7 |
|
brv |
|
8 |
|
vex |
|
9 |
8 1 2
|
brtxp |
|
10 |
7 9
|
mpbiran |
|
11 |
2
|
epeli |
|
12 |
10 11
|
bitri |
|
13 |
|
brv |
|
14 |
8 1 2
|
brtxp |
|
15 |
13 14
|
mpbiran2 |
|
16 |
12 15
|
bibi12i |
|
17 |
6 16
|
xchbinx |
|
18 |
17
|
exbii |
|
19 |
5 18
|
bitri |
|
20 |
|
exnal |
|
21 |
3 19 20
|
3bitrri |
|
22 |
21
|
con1bii |
|