Description: Absorption into embedded conjunct. (Contributed by NM, 20-Jul-1996) (Proof shortened by Wolf Lammen, 9-Dec-2012)
Ref | Expression | ||
---|---|---|---|
Assertion | anabs5 | |- ( ( ph /\ ( ph /\ ps ) ) <-> ( ph /\ ps ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ibar | |- ( ph -> ( ps <-> ( ph /\ ps ) ) ) |
|
2 | 1 | bicomd | |- ( ph -> ( ( ph /\ ps ) <-> ps ) ) |
3 | 2 | pm5.32i | |- ( ( ph /\ ( ph /\ ps ) ) <-> ( ph /\ ps ) ) |