| Step |
Hyp |
Ref |
Expression |
| 1 |
|
dfifp4 |
|- ( if- ( ph , ps , ch ) <-> ( ( -. ph \/ ps ) /\ ( ph \/ ch ) ) ) |
| 2 |
1
|
bibi2i |
|- ( ( th <-> if- ( ph , ps , ch ) ) <-> ( th <-> ( ( -. ph \/ ps ) /\ ( ph \/ ch ) ) ) ) |
| 3 |
|
dfbi2 |
|- ( ( th <-> ( ( -. ph \/ ps ) /\ ( ph \/ ch ) ) ) <-> ( ( th -> ( ( -. ph \/ ps ) /\ ( ph \/ ch ) ) ) /\ ( ( ( -. ph \/ ps ) /\ ( ph \/ ch ) ) -> th ) ) ) |
| 4 |
|
imor |
|- ( ( th -> ( ( -. ph \/ ps ) /\ ( ph \/ ch ) ) ) <-> ( -. th \/ ( ( -. ph \/ ps ) /\ ( ph \/ ch ) ) ) ) |
| 5 |
|
ordi |
|- ( ( -. th \/ ( ( -. ph \/ ps ) /\ ( ph \/ ch ) ) ) <-> ( ( -. th \/ ( -. ph \/ ps ) ) /\ ( -. th \/ ( ph \/ ch ) ) ) ) |
| 6 |
|
ancomst |
|- ( ( ( ph /\ th ) -> ps ) <-> ( ( th /\ ph ) -> ps ) ) |
| 7 |
|
impexp |
|- ( ( ( th /\ ph ) -> ps ) <-> ( th -> ( ph -> ps ) ) ) |
| 8 |
|
imor |
|- ( ( ph -> ps ) <-> ( -. ph \/ ps ) ) |
| 9 |
8
|
imbi2i |
|- ( ( th -> ( ph -> ps ) ) <-> ( th -> ( -. ph \/ ps ) ) ) |
| 10 |
|
imor |
|- ( ( th -> ( -. ph \/ ps ) ) <-> ( -. th \/ ( -. ph \/ ps ) ) ) |
| 11 |
9 10
|
bitri |
|- ( ( th -> ( ph -> ps ) ) <-> ( -. th \/ ( -. ph \/ ps ) ) ) |
| 12 |
6 7 11
|
3bitrri |
|- ( ( -. th \/ ( -. ph \/ ps ) ) <-> ( ( ph /\ th ) -> ps ) ) |
| 13 |
|
imor |
|- ( ( th -> ( ph \/ ch ) ) <-> ( -. th \/ ( ph \/ ch ) ) ) |
| 14 |
13
|
bicomi |
|- ( ( -. th \/ ( ph \/ ch ) ) <-> ( th -> ( ph \/ ch ) ) ) |
| 15 |
12 14
|
anbi12i |
|- ( ( ( -. th \/ ( -. ph \/ ps ) ) /\ ( -. th \/ ( ph \/ ch ) ) ) <-> ( ( ( ph /\ th ) -> ps ) /\ ( th -> ( ph \/ ch ) ) ) ) |
| 16 |
4 5 15
|
3bitri |
|- ( ( th -> ( ( -. ph \/ ps ) /\ ( ph \/ ch ) ) ) <-> ( ( ( ph /\ th ) -> ps ) /\ ( th -> ( ph \/ ch ) ) ) ) |
| 17 |
8
|
bicomi |
|- ( ( -. ph \/ ps ) <-> ( ph -> ps ) ) |
| 18 |
|
df-or |
|- ( ( ph \/ ch ) <-> ( -. ph -> ch ) ) |
| 19 |
17 18
|
anbi12i |
|- ( ( ( -. ph \/ ps ) /\ ( ph \/ ch ) ) <-> ( ( ph -> ps ) /\ ( -. ph -> ch ) ) ) |
| 20 |
|
cases2 |
|- ( ( ( ph /\ ps ) \/ ( -. ph /\ ch ) ) <-> ( ( ph -> ps ) /\ ( -. ph -> ch ) ) ) |
| 21 |
20
|
bicomi |
|- ( ( ( ph -> ps ) /\ ( -. ph -> ch ) ) <-> ( ( ph /\ ps ) \/ ( -. ph /\ ch ) ) ) |
| 22 |
19 21
|
bitri |
|- ( ( ( -. ph \/ ps ) /\ ( ph \/ ch ) ) <-> ( ( ph /\ ps ) \/ ( -. ph /\ ch ) ) ) |
| 23 |
22
|
imbi1i |
|- ( ( ( ( -. ph \/ ps ) /\ ( ph \/ ch ) ) -> th ) <-> ( ( ( ph /\ ps ) \/ ( -. ph /\ ch ) ) -> th ) ) |
| 24 |
|
jaob |
|- ( ( ( ( ph /\ ps ) \/ ( -. ph /\ ch ) ) -> th ) <-> ( ( ( ph /\ ps ) -> th ) /\ ( ( -. ph /\ ch ) -> th ) ) ) |
| 25 |
|
ancomst |
|- ( ( ( -. ph /\ ch ) -> th ) <-> ( ( ch /\ -. ph ) -> th ) ) |
| 26 |
|
pm5.6 |
|- ( ( ( ch /\ -. ph ) -> th ) <-> ( ch -> ( ph \/ th ) ) ) |
| 27 |
25 26
|
bitri |
|- ( ( ( -. ph /\ ch ) -> th ) <-> ( ch -> ( ph \/ th ) ) ) |
| 28 |
27
|
anbi2i |
|- ( ( ( ( ph /\ ps ) -> th ) /\ ( ( -. ph /\ ch ) -> th ) ) <-> ( ( ( ph /\ ps ) -> th ) /\ ( ch -> ( ph \/ th ) ) ) ) |
| 29 |
23 24 28
|
3bitri |
|- ( ( ( ( -. ph \/ ps ) /\ ( ph \/ ch ) ) -> th ) <-> ( ( ( ph /\ ps ) -> th ) /\ ( ch -> ( ph \/ th ) ) ) ) |
| 30 |
16 29
|
anbi12i |
|- ( ( ( th -> ( ( -. ph \/ ps ) /\ ( ph \/ ch ) ) ) /\ ( ( ( -. ph \/ ps ) /\ ( ph \/ ch ) ) -> th ) ) <-> ( ( ( ( ph /\ th ) -> ps ) /\ ( th -> ( ph \/ ch ) ) ) /\ ( ( ( ph /\ ps ) -> th ) /\ ( ch -> ( ph \/ th ) ) ) ) ) |
| 31 |
3 30
|
bitri |
|- ( ( th <-> ( ( -. ph \/ ps ) /\ ( ph \/ ch ) ) ) <-> ( ( ( ( ph /\ th ) -> ps ) /\ ( th -> ( ph \/ ch ) ) ) /\ ( ( ( ph /\ ps ) -> th ) /\ ( ch -> ( ph \/ th ) ) ) ) ) |
| 32 |
|
ancom |
|- ( ( ( ( ( ph /\ th ) -> ps ) /\ ( th -> ( ph \/ ch ) ) ) /\ ( ( ( ph /\ ps ) -> th ) /\ ( ch -> ( ph \/ th ) ) ) ) <-> ( ( ( ( ph /\ ps ) -> th ) /\ ( ch -> ( ph \/ th ) ) ) /\ ( ( ( ph /\ th ) -> ps ) /\ ( th -> ( ph \/ ch ) ) ) ) ) |
| 33 |
|
an4 |
|- ( ( ( ( ( ph /\ ps ) -> th ) /\ ( ch -> ( ph \/ th ) ) ) /\ ( ( ( ph /\ th ) -> ps ) /\ ( th -> ( ph \/ ch ) ) ) ) <-> ( ( ( ( ph /\ ps ) -> th ) /\ ( ( ph /\ th ) -> ps ) ) /\ ( ( ch -> ( ph \/ th ) ) /\ ( th -> ( ph \/ ch ) ) ) ) ) |
| 34 |
32 33
|
bitri |
|- ( ( ( ( ( ph /\ th ) -> ps ) /\ ( th -> ( ph \/ ch ) ) ) /\ ( ( ( ph /\ ps ) -> th ) /\ ( ch -> ( ph \/ th ) ) ) ) <-> ( ( ( ( ph /\ ps ) -> th ) /\ ( ( ph /\ th ) -> ps ) ) /\ ( ( ch -> ( ph \/ th ) ) /\ ( th -> ( ph \/ ch ) ) ) ) ) |
| 35 |
2 31 34
|
3bitri |
|- ( ( th <-> if- ( ph , ps , ch ) ) <-> ( ( ( ( ph /\ ps ) -> th ) /\ ( ( ph /\ th ) -> ps ) ) /\ ( ( ch -> ( ph \/ th ) ) /\ ( th -> ( ph \/ ch ) ) ) ) ) |