Step |
Hyp |
Ref |
Expression |
1 |
|
nnre |
|
2 |
|
3re |
|
3 |
2
|
a1i |
|
4 |
3 1
|
remulcld |
|
5 |
4
|
rehalfcld |
|
6 |
5
|
ceilcld |
|
7 |
6
|
zred |
|
8 |
|
2re |
|
9 |
8
|
a1i |
|
10 |
|
nnrp |
|
11 |
|
2lt3 |
|
12 |
11
|
a1i |
|
13 |
9 3 10 12
|
ltmul1dd |
|
14 |
|
2pos |
|
15 |
14
|
a1i |
|
16 |
|
ltmuldiv2 |
|
17 |
1 4 9 15 16
|
syl112anc |
|
18 |
13 17
|
mpbid |
|
19 |
5
|
ceilged |
|
20 |
1 5 7 18 19
|
ltletrd |
|