| Step |
Hyp |
Ref |
Expression |
| 1 |
|
ifpidg |
|- ( ( ph <-> if- ( ph , ps , ch ) ) <-> ( ( ( ( ph /\ ps ) -> ph ) /\ ( ( ph /\ ph ) -> ps ) ) /\ ( ( ch -> ( ph \/ ph ) ) /\ ( ph -> ( ph \/ ch ) ) ) ) ) |
| 2 |
|
ancom |
|- ( ( ( ( ( ph /\ ps ) -> ph ) /\ ( ( ph /\ ph ) -> ps ) ) /\ ( ( ch -> ( ph \/ ph ) ) /\ ( ph -> ( ph \/ ch ) ) ) ) <-> ( ( ( ch -> ( ph \/ ph ) ) /\ ( ph -> ( ph \/ ch ) ) ) /\ ( ( ( ph /\ ps ) -> ph ) /\ ( ( ph /\ ph ) -> ps ) ) ) ) |
| 3 |
|
pm4.25 |
|- ( ph <-> ( ph \/ ph ) ) |
| 4 |
3
|
imbi2i |
|- ( ( ch -> ph ) <-> ( ch -> ( ph \/ ph ) ) ) |
| 5 |
|
orc |
|- ( ph -> ( ph \/ ch ) ) |
| 6 |
5
|
biantru |
|- ( ( ch -> ( ph \/ ph ) ) <-> ( ( ch -> ( ph \/ ph ) ) /\ ( ph -> ( ph \/ ch ) ) ) ) |
| 7 |
4 6
|
bitr2i |
|- ( ( ( ch -> ( ph \/ ph ) ) /\ ( ph -> ( ph \/ ch ) ) ) <-> ( ch -> ph ) ) |
| 8 |
|
pm4.24 |
|- ( ph <-> ( ph /\ ph ) ) |
| 9 |
8
|
imbi1i |
|- ( ( ph -> ps ) <-> ( ( ph /\ ph ) -> ps ) ) |
| 10 |
|
simpl |
|- ( ( ph /\ ps ) -> ph ) |
| 11 |
10
|
biantrur |
|- ( ( ( ph /\ ph ) -> ps ) <-> ( ( ( ph /\ ps ) -> ph ) /\ ( ( ph /\ ph ) -> ps ) ) ) |
| 12 |
9 11
|
bitr2i |
|- ( ( ( ( ph /\ ps ) -> ph ) /\ ( ( ph /\ ph ) -> ps ) ) <-> ( ph -> ps ) ) |
| 13 |
7 12
|
anbi12i |
|- ( ( ( ( ch -> ( ph \/ ph ) ) /\ ( ph -> ( ph \/ ch ) ) ) /\ ( ( ( ph /\ ps ) -> ph ) /\ ( ( ph /\ ph ) -> ps ) ) ) <-> ( ( ch -> ph ) /\ ( ph -> ps ) ) ) |
| 14 |
1 2 13
|
3bitri |
|- ( ( ph <-> if- ( ph , ps , ch ) ) <-> ( ( ch -> ph ) /\ ( ph -> ps ) ) ) |