| Step |
Hyp |
Ref |
Expression |
| 1 |
|
pw2divs0d.1 |
|- ( ph -> N e. NN0_s ) |
| 2 |
|
2sno |
|- 2s e. No |
| 3 |
|
expscl |
|- ( ( 2s e. No /\ N e. NN0_s ) -> ( 2s ^su N ) e. No ) |
| 4 |
2 1 3
|
sylancr |
|- ( ph -> ( 2s ^su N ) e. No ) |
| 5 |
|
muls01 |
|- ( ( 2s ^su N ) e. No -> ( ( 2s ^su N ) x.s 0s ) = 0s ) |
| 6 |
4 5
|
syl |
|- ( ph -> ( ( 2s ^su N ) x.s 0s ) = 0s ) |
| 7 |
|
0sno |
|- 0s e. No |
| 8 |
7
|
a1i |
|- ( ph -> 0s e. No ) |
| 9 |
8 8 1
|
pw2divsmuld |
|- ( ph -> ( ( 0s /su ( 2s ^su N ) ) = 0s <-> ( ( 2s ^su N ) x.s 0s ) = 0s ) ) |
| 10 |
6 9
|
mpbird |
|- ( ph -> ( 0s /su ( 2s ^su N ) ) = 0s ) |