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 ) ) ) ) ) |