Description: 3imp with middle implication of the hypothesis a biconditional. (Contributed by Alan Sare, 6-Nov-2017)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | bi23imp13.1 | |- ( ph -> ( ps <-> ( ch -> th ) ) ) |
|
| Assertion | bi23imp13 | |- ( ( ph /\ ps /\ ch ) -> th ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | bi23imp13.1 | |- ( ph -> ( ps <-> ( ch -> th ) ) ) |
|
| 2 | 1 | biimpd | |- ( ph -> ( ps -> ( ch -> th ) ) ) |
| 3 | 2 | 3imp | |- ( ( ph /\ ps /\ ch ) -> th ) |