Step |
Hyp |
Ref |
Expression |
1 |
|
fzfid |
|
2 |
|
nn0cn |
|
3 |
2
|
adantr |
|
4 |
3
|
sqcld |
|
5 |
4 3
|
subcld |
|
6 |
|
2cnd |
|
7 |
|
elfznn |
|
8 |
7
|
nncnd |
|
9 |
8
|
adantl |
|
10 |
6 9
|
mulcld |
|
11 |
|
1cnd |
|
12 |
10 11
|
subcld |
|
13 |
1 5 12
|
fsumadd |
|
14 |
|
id |
|
15 |
2
|
sqcld |
|
16 |
15 2
|
subcld |
|
17 |
14 16
|
fz1sumconst |
|
18 |
2 15 2
|
subdid |
|
19 |
|
df-3 |
|
20 |
19
|
oveq2i |
|
21 |
|
2nn0 |
|
22 |
21
|
a1i |
|
23 |
2 22
|
expp1d |
|
24 |
20 23
|
eqtrid |
|
25 |
15 2
|
mulcomd |
|
26 |
24 25
|
eqtr2d |
|
27 |
2
|
sqvald |
|
28 |
27
|
eqcomd |
|
29 |
26 28
|
oveq12d |
|
30 |
17 18 29
|
3eqtrd |
|
31 |
|
oddnumth |
|
32 |
30 31
|
oveq12d |
|
33 |
|
3nn0 |
|
34 |
33
|
a1i |
|
35 |
2 34
|
expcld |
|
36 |
35 15
|
npcand |
|
37 |
13 32 36
|
3eqtrd |
|