Step |
Hyp |
Ref |
Expression |
1 |
|
fvsnun.1 |
|
2 |
|
fvsnun.2 |
|
3 |
|
fvsnun.3 |
|
4 |
3
|
reseq1i |
|
5 |
|
resundir |
|
6 |
|
incom |
|
7 |
|
disjdif |
|
8 |
6 7
|
eqtri |
|
9 |
|
resdisj |
|
10 |
8 9
|
ax-mp |
|
11 |
10
|
uneq2i |
|
12 |
|
un0 |
|
13 |
11 12
|
eqtri |
|
14 |
5 13
|
eqtri |
|
15 |
4 14
|
eqtri |
|
16 |
15
|
fveq1i |
|
17 |
|
snidg |
|
18 |
1 17
|
syl |
|
19 |
18
|
fvresd |
|
20 |
18
|
fvresd |
|
21 |
|
fvsng |
|
22 |
1 2 21
|
syl2anc |
|
23 |
20 22
|
eqtrd |
|
24 |
16 19 23
|
3eqtr3a |
|