| Step |
Hyp |
Ref |
Expression |
| 1 |
|
un2122.1 |
|- ( ( ( ph /\ ps ) /\ ps /\ ps ) -> ch ) |
| 2 |
|
3anass |
|- ( ( ( ph /\ ps ) /\ ps /\ ps ) <-> ( ( ph /\ ps ) /\ ( ps /\ ps ) ) ) |
| 3 |
|
anandir |
|- ( ( ( ph /\ ps ) /\ ps ) <-> ( ( ph /\ ps ) /\ ( ps /\ ps ) ) ) |
| 4 |
|
ancom |
|- ( ( ( ph /\ ps ) /\ ps ) <-> ( ps /\ ( ph /\ ps ) ) ) |
| 5 |
|
anabs7 |
|- ( ( ps /\ ( ph /\ ps ) ) <-> ( ph /\ ps ) ) |
| 6 |
4 5
|
bitri |
|- ( ( ( ph /\ ps ) /\ ps ) <-> ( ph /\ ps ) ) |
| 7 |
3 6
|
bitr3i |
|- ( ( ( ph /\ ps ) /\ ( ps /\ ps ) ) <-> ( ph /\ ps ) ) |
| 8 |
2 7
|
bitri |
|- ( ( ( ph /\ ps ) /\ ps /\ ps ) <-> ( ph /\ ps ) ) |
| 9 |
8 1
|
sylbir |
|- ( ( ph /\ ps ) -> ch ) |