Description: Convert triple conjunction to conjunction, then commute. (Contributed by Jonathan Ben-Naim, 3-Jun-2011)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 3anan32 | |- ( ( ph /\ ps /\ ch ) <-> ( ( ph /\ ch ) /\ ps ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-3an | |- ( ( ph /\ ps /\ ch ) <-> ( ( ph /\ ps ) /\ ch ) ) |
|
| 2 | an32 | |- ( ( ( ph /\ ps ) /\ ch ) <-> ( ( ph /\ ch ) /\ ps ) ) |
|
| 3 | 1 2 | bitri | |- ( ( ph /\ ps /\ ch ) <-> ( ( ph /\ ch ) /\ ps ) ) |