Step |
Hyp |
Ref |
Expression |
1 |
|
subsf |
|
2 |
|
0sno |
|
3 |
|
opelxpi |
|
4 |
2 3
|
mpan2 |
|
5 |
|
subsval |
|
6 |
2 5
|
mpan2 |
|
7 |
|
negs0s |
|
8 |
7
|
oveq2i |
|
9 |
|
addsrid |
|
10 |
8 9
|
eqtrid |
|
11 |
6 10
|
eqtr2d |
|
12 |
|
fveq2 |
|
13 |
|
df-ov |
|
14 |
12 13
|
eqtr4di |
|
15 |
14
|
rspceeqv |
|
16 |
4 11 15
|
syl2anc |
|
17 |
16
|
rgen |
|
18 |
|
dffo3 |
|
19 |
1 17 18
|
mpbir2an |
|