Step |
Hyp |
Ref |
Expression |
1 |
|
psubspset.l |
|
2 |
|
psubspset.j |
|
3 |
|
psubspset.a |
|
4 |
|
psubspset.s |
|
5 |
1 2 3 4
|
psubspset |
|
6 |
5
|
eleq2d |
|
7 |
3
|
fvexi |
|
8 |
7
|
ssex |
|
9 |
8
|
adantr |
|
10 |
|
sseq1 |
|
11 |
|
eleq2 |
|
12 |
11
|
imbi2d |
|
13 |
12
|
ralbidv |
|
14 |
13
|
raleqbi1dv |
|
15 |
14
|
raleqbi1dv |
|
16 |
10 15
|
anbi12d |
|
17 |
9 16
|
elab3 |
|
18 |
6 17
|
syl6bb |
|