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Description: Disjunction of three antecedents. (Contributed by NM, 13-Sep-2011) (Proof shortened by Hongxiu Chen, 29-Jun-2025)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 3jaob | |- ( ( ( ph \/ ch \/ th ) -> ps ) <-> ( ( ph -> ps ) /\ ( ch -> ps ) /\ ( th -> ps ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | pm5.53 | |- ( ( ( ( ph \/ ch ) \/ th ) -> ps ) <-> ( ( ( ph -> ps ) /\ ( ch -> ps ) ) /\ ( th -> ps ) ) ) |
|
| 2 | df-3or | |- ( ( ph \/ ch \/ th ) <-> ( ( ph \/ ch ) \/ th ) ) |
|
| 3 | 2 | imbi1i | |- ( ( ( ph \/ ch \/ th ) -> ps ) <-> ( ( ( ph \/ ch ) \/ th ) -> ps ) ) |
| 4 | df-3an | |- ( ( ( ph -> ps ) /\ ( ch -> ps ) /\ ( th -> ps ) ) <-> ( ( ( ph -> ps ) /\ ( ch -> ps ) ) /\ ( th -> ps ) ) ) |
|
| 5 | 1 3 4 | 3bitr4i | |- ( ( ( ph \/ ch \/ th ) -> ps ) <-> ( ( ph -> ps ) /\ ( ch -> ps ) /\ ( th -> ps ) ) ) |