Step |
Hyp |
Ref |
Expression |
1 |
|
preimane.f |
|
2 |
|
preimane.x |
|
3 |
|
preimane.y |
|
4 |
|
preimane.1 |
|
5 |
|
sneqrg |
|
6 |
3 5
|
syl |
|
7 |
6
|
necon3d |
|
8 |
2 7
|
mpd |
|
9 |
|
funimacnv |
|
10 |
1 9
|
syl |
|
11 |
3
|
snssd |
|
12 |
|
df-ss |
|
13 |
11 12
|
sylib |
|
14 |
10 13
|
eqtrd |
|
15 |
|
funimacnv |
|
16 |
1 15
|
syl |
|
17 |
4
|
snssd |
|
18 |
|
df-ss |
|
19 |
17 18
|
sylib |
|
20 |
16 19
|
eqtrd |
|
21 |
8 14 20
|
3netr4d |
|
22 |
|
imaeq2 |
|
23 |
22
|
necon3i |
|
24 |
21 23
|
syl |
|