Step |
Hyp |
Ref |
Expression |
1 |
|
ustval |
|
2 |
1
|
eleq2d |
|
3 |
|
simp1 |
|
4 |
|
sqxpexg |
|
5 |
4
|
pwexd |
|
6 |
5
|
adantr |
|
7 |
|
simpr |
|
8 |
6 7
|
ssexd |
|
9 |
8
|
ex |
|
10 |
3 9
|
syl5 |
|
11 |
|
sseq1 |
|
12 |
|
eleq2 |
|
13 |
|
eleq2 |
|
14 |
13
|
imbi2d |
|
15 |
14
|
ralbidv |
|
16 |
|
eleq2 |
|
17 |
16
|
raleqbi1dv |
|
18 |
|
eleq2 |
|
19 |
|
rexeq |
|
20 |
18 19
|
3anbi23d |
|
21 |
15 17 20
|
3anbi123d |
|
22 |
21
|
raleqbi1dv |
|
23 |
11 12 22
|
3anbi123d |
|
24 |
23
|
elab3g |
|
25 |
10 24
|
syl |
|
26 |
2 25
|
bitrd |
|