Description: Inference commuting conjunction in antecedent. (Contributed by NM, 21-Apr-1994)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | ancoms.1 | |- ( ( ph /\ ps ) -> ch ) |
|
| Assertion | ancoms | |- ( ( ps /\ ph ) -> ch ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ancoms.1 | |- ( ( ph /\ ps ) -> ch ) |
|
| 2 | 1 | expcom | |- ( ps -> ( ph -> ch ) ) |
| 3 | 2 | imp | |- ( ( ps /\ ph ) -> ch ) |