Step |
Hyp |
Ref |
Expression |
1 |
|
acosval |
|
2 |
1
|
fveq2d |
|
3 |
|
halfpire |
|
4 |
3
|
recni |
|
5 |
|
asincl |
|
6 |
|
resub |
|
7 |
4 5 6
|
sylancr |
|
8 |
|
rere |
|
9 |
3 8
|
ax-mp |
|
10 |
9
|
oveq1i |
|
11 |
7 10
|
eqtrdi |
|
12 |
2 11
|
eqtrd |
|
13 |
5
|
recld |
|
14 |
|
resubcl |
|
15 |
3 13 14
|
sylancr |
|
16 |
|
asinbnd |
|
17 |
|
neghalfpire |
|
18 |
17 3
|
elicc2i |
|
19 |
16 18
|
sylib |
|
20 |
19
|
simp3d |
|
21 |
|
subge0 |
|
22 |
3 13 21
|
sylancr |
|
23 |
20 22
|
mpbird |
|
24 |
3
|
a1i |
|
25 |
|
pire |
|
26 |
25
|
a1i |
|
27 |
25
|
recni |
|
28 |
17
|
recni |
|
29 |
27 4
|
negsubi |
|
30 |
|
pidiv2halves |
|
31 |
27 4 4 30
|
subaddrii |
|
32 |
29 31
|
eqtri |
|
33 |
4 27 28 32
|
subaddrii |
|
34 |
19
|
simp2d |
|
35 |
33 34
|
eqbrtrid |
|
36 |
24 26 13 35
|
subled |
|
37 |
|
0re |
|
38 |
37 25
|
elicc2i |
|
39 |
15 23 36 38
|
syl3anbrc |
|
40 |
12 39
|
eqeltrd |
|