Description: Importation inference from a logical equivalence. (Contributed by NM, 3-May-1994)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | biimpa.1 | |- ( ph -> ( ps <-> ch ) ) |
|
| Assertion | biimpar | |- ( ( ph /\ ch ) -> ps ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | biimpa.1 | |- ( ph -> ( ps <-> ch ) ) |
|
| 2 | 1 | biimprd | |- ( ph -> ( ch -> ps ) ) |
| 3 | 2 | imp | |- ( ( ph /\ ch ) -> ps ) |