Step |
Hyp |
Ref |
Expression |
1 |
|
halfcn |
|
2 |
1
|
2timesi |
|
3 |
|
2cn |
|
4 |
|
2ne0 |
|
5 |
3 4
|
recidi |
|
6 |
2 5
|
eqtr3i |
|
7 |
6
|
oveq2i |
|
8 |
|
recn |
|
9 |
1
|
a1i |
|
10 |
8 9 9
|
nppcan3d |
|
11 |
7 10
|
syl5eqr |
|
12 |
|
halfre |
|
13 |
|
readdcl |
|
14 |
12 13
|
mpan2 |
|
15 |
|
fllep1 |
|
16 |
14 15
|
syl |
|
17 |
11 16
|
eqbrtrd |
|
18 |
|
resubcl |
|
19 |
12 18
|
mpan2 |
|
20 |
|
reflcl |
|
21 |
14 20
|
syl |
|
22 |
|
1red |
|
23 |
19 21 22
|
leadd1d |
|
24 |
17 23
|
mpbird |
|
25 |
|
flle |
|
26 |
14 25
|
syl |
|
27 |
|
id |
|
28 |
12
|
a1i |
|
29 |
|
absdifle |
|
30 |
21 27 28 29
|
syl3anc |
|
31 |
24 26 30
|
mpbir2and |
|