Description: Move conjunction outside of biconditional. (Contributed by Mario Carneiro, 11-Sep-2015)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | baibd.1 | |- ( ph -> ( ps <-> ( ch /\ th ) ) ) |
|
| Assertion | rbaibd | |- ( ( ph /\ th ) -> ( ps <-> ch ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | baibd.1 | |- ( ph -> ( ps <-> ( ch /\ th ) ) ) |
|
| 2 | 1 | biancomd | |- ( ph -> ( ps <-> ( th /\ ch ) ) ) |
| 3 | 2 | baibd | |- ( ( ph /\ th ) -> ( ps <-> ch ) ) |