Description: Commutative law for a conjunction with a triple conjunction: second and forth positions interchanged. (Contributed by AV, 18-Feb-2022)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 3an4ancom24 | |- ( ( ( ph /\ ps /\ ch ) /\ th ) <-> ( ( ph /\ th /\ ch ) /\ ps ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | an4com24 | |- ( ( ( ph /\ ps ) /\ ( ch /\ th ) ) <-> ( ( ph /\ th ) /\ ( ch /\ ps ) ) ) | |
| 2 | 3an4anass | |- ( ( ( ph /\ ps /\ ch ) /\ th ) <-> ( ( ph /\ ps ) /\ ( ch /\ th ) ) ) | |
| 3 | 3an4anass | |- ( ( ( ph /\ th /\ ch ) /\ ps ) <-> ( ( ph /\ th ) /\ ( ch /\ ps ) ) ) | |
| 4 | 1 2 3 | 3bitr4i | |- ( ( ( ph /\ ps /\ ch ) /\ th ) <-> ( ( ph /\ th /\ ch ) /\ ps ) ) |