Step |
Hyp |
Ref |
Expression |
1 |
|
dprdff.w |
|
2 |
|
dprdff.1 |
|
3 |
|
dprdff.2 |
|
4 |
|
elex |
|
5 |
4
|
a1i |
|
6 |
2 3
|
dprddomcld |
|
7 |
|
fnex |
|
8 |
7
|
expcom |
|
9 |
6 8
|
syl |
|
10 |
9
|
adantrd |
|
11 |
|
fveq2 |
|
12 |
11
|
cbvixpv |
|
13 |
12
|
eleq2i |
|
14 |
|
elixp2 |
|
15 |
|
3anass |
|
16 |
13 14 15
|
3bitri |
|
17 |
16
|
baib |
|
18 |
17
|
a1i |
|
19 |
5 10 18
|
pm5.21ndd |
|
20 |
19
|
anbi1d |
|
21 |
|
breq1 |
|
22 |
21 1
|
elrab2 |
|
23 |
|
df-3an |
|
24 |
20 22 23
|
3bitr4g |
|