| Step |
Hyp |
Ref |
Expression |
| 1 |
|
fzoval |
|
| 2 |
1
|
3ad2ant2 |
|
| 3 |
2
|
raleqdv |
|
| 4 |
|
peano2zm |
|
| 5 |
|
fzshftral |
|
| 6 |
4 5
|
syl3an2 |
|
| 7 |
|
zaddcl |
|
| 8 |
7
|
3adant1 |
|
| 9 |
|
fzoval |
|
| 10 |
8 9
|
syl |
|
| 11 |
|
zcn |
|
| 12 |
11
|
adantr |
|
| 13 |
|
zcn |
|
| 14 |
13
|
adantl |
|
| 15 |
|
1cnd |
|
| 16 |
12 14 15
|
addsubd |
|
| 17 |
16
|
3adant1 |
|
| 18 |
17
|
oveq2d |
|
| 19 |
10 18
|
eqtr2d |
|
| 20 |
19
|
raleqdv |
|
| 21 |
3 6 20
|
3bitrd |
|