Step |
Hyp |
Ref |
Expression |
1 |
|
neg0 |
|
2 |
|
simpr |
|
3 |
2
|
negeqd |
|
4 |
1 3 2
|
3eqtr4a |
|
5 |
4
|
oveq2d |
|
6 |
|
nn0z |
|
7 |
|
lgsneg |
|
8 |
6 7
|
syl3an1 |
|
9 |
|
nn0nlt0 |
|
10 |
9
|
3ad2ant1 |
|
11 |
10
|
iffalsed |
|
12 |
11
|
oveq1d |
|
13 |
6
|
3ad2ant1 |
|
14 |
|
simp2 |
|
15 |
|
lgscl |
|
16 |
13 14 15
|
syl2anc |
|
17 |
16
|
zcnd |
|
18 |
17
|
mulid2d |
|
19 |
8 12 18
|
3eqtrd |
|
20 |
19
|
3expa |
|
21 |
5 20
|
pm2.61dane |
|