Step |
Hyp |
Ref |
Expression |
1 |
|
evenz |
|
2 |
|
evenz |
|
3 |
|
zltp1le |
|
4 |
1 2 3
|
syl2anr |
|
5 |
1
|
zred |
|
6 |
|
peano2re |
|
7 |
5 6
|
syl |
|
8 |
2
|
zred |
|
9 |
|
leloe |
|
10 |
7 8 9
|
syl2anr |
|
11 |
1
|
peano2zd |
|
12 |
|
zltp1le |
|
13 |
11 2 12
|
syl2anr |
|
14 |
1
|
zcnd |
|
15 |
14
|
adantl |
|
16 |
|
add1p1 |
|
17 |
15 16
|
syl |
|
18 |
17
|
breq1d |
|
19 |
18
|
biimpd |
|
20 |
13 19
|
sylbid |
|
21 |
|
evenp1odd |
|
22 |
|
zneoALTV |
|
23 |
|
eqneqall |
|
24 |
23
|
eqcoms |
|
25 |
22 24
|
syl5com |
|
26 |
21 25
|
sylan2 |
|
27 |
20 26
|
jaod |
|
28 |
10 27
|
sylbid |
|
29 |
4 28
|
sylbid |
|
30 |
29
|
3impia |
|