Step |
Hyp |
Ref |
Expression |
1 |
|
psgnval.g |
|
2 |
|
psgnval.t |
|
3 |
|
psgnval.n |
|
4 |
|
eqid |
|
5 |
2 1 4
|
symgtrf |
|
6 |
5
|
sseli |
|
7 |
4
|
gsumws1 |
|
8 |
6 7
|
syl |
|
9 |
8
|
fveq2d |
|
10 |
1 4
|
elbasfv |
|
11 |
6 10
|
syl |
|
12 |
|
s1cl |
|
13 |
1 2 3
|
psgnvalii |
|
14 |
11 12 13
|
syl2anc |
|
15 |
|
s1len |
|
16 |
15
|
oveq2i |
|
17 |
|
neg1cn |
|
18 |
|
exp1 |
|
19 |
17 18
|
ax-mp |
|
20 |
16 19
|
eqtri |
|
21 |
14 20
|
eqtrdi |
|
22 |
9 21
|
eqtr3d |
|