Step |
Hyp |
Ref |
Expression |
1 |
|
dfrdg2 |
|
2 |
|
iftrue |
|
3 |
2
|
ifeq1d |
|
4 |
3
|
eqeq2d |
|
5 |
4
|
ralbidv |
|
6 |
5
|
anbi2d |
|
7 |
6
|
rexbidv |
|
8 |
7
|
abbidv |
|
9 |
8
|
unieqd |
|
10 |
1 9
|
eqtr4d |
|
11 |
|
0ex |
|
12 |
|
dfrdg2 |
|
13 |
11 12
|
ax-mp |
|
14 |
|
rdgprc |
|
15 |
|
iffalse |
|
16 |
15
|
ifeq1d |
|
17 |
16
|
eqeq2d |
|
18 |
17
|
ralbidv |
|
19 |
18
|
anbi2d |
|
20 |
19
|
rexbidv |
|
21 |
20
|
abbidv |
|
22 |
21
|
unieqd |
|
23 |
13 14 22
|
3eqtr4a |
|
24 |
10 23
|
pm2.61i |
|