Step |
Hyp |
Ref |
Expression |
1 |
|
df-nan |
|- ( ( ph -/\ ps ) <-> -. ( ph /\ ps ) ) |
2 |
|
xor2 |
|- ( ( ph \/_ ps ) <-> ( ( ph \/ ps ) /\ -. ( ph /\ ps ) ) ) |
3 |
2
|
rbaibr |
|- ( -. ( ph /\ ps ) -> ( ( ph \/ ps ) <-> ( ph \/_ ps ) ) ) |
4 |
2
|
bibi2i |
|- ( ( ( ph \/ ps ) <-> ( ph \/_ ps ) ) <-> ( ( ph \/ ps ) <-> ( ( ph \/ ps ) /\ -. ( ph /\ ps ) ) ) ) |
5 |
|
pm4.71 |
|- ( ( ( ph \/ ps ) -> -. ( ph /\ ps ) ) <-> ( ( ph \/ ps ) <-> ( ( ph \/ ps ) /\ -. ( ph /\ ps ) ) ) ) |
6 |
|
simpl |
|- ( ( ph /\ ps ) -> ph ) |
7 |
6
|
orcd |
|- ( ( ph /\ ps ) -> ( ph \/ ps ) ) |
8 |
7
|
con3i |
|- ( -. ( ph \/ ps ) -> -. ( ph /\ ps ) ) |
9 |
|
id |
|- ( -. ( ph /\ ps ) -> -. ( ph /\ ps ) ) |
10 |
8 9
|
ja |
|- ( ( ( ph \/ ps ) -> -. ( ph /\ ps ) ) -> -. ( ph /\ ps ) ) |
11 |
5 10
|
sylbir |
|- ( ( ( ph \/ ps ) <-> ( ( ph \/ ps ) /\ -. ( ph /\ ps ) ) ) -> -. ( ph /\ ps ) ) |
12 |
4 11
|
sylbi |
|- ( ( ( ph \/ ps ) <-> ( ph \/_ ps ) ) -> -. ( ph /\ ps ) ) |
13 |
3 12
|
impbii |
|- ( -. ( ph /\ ps ) <-> ( ( ph \/ ps ) <-> ( ph \/_ ps ) ) ) |
14 |
1 13
|
bitri |
|- ( ( ph -/\ ps ) <-> ( ( ph \/ ps ) <-> ( ph \/_ ps ) ) ) |