Description: From one negated implication it is not the case its nonnegated form and a random others are both true. (Contributed by Jarvin Udandy, 11-Sep-2020)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | onenotinotbothi.1 | |- -. ( ph -> ps ) |
|
| Assertion | onenotinotbothi | |- -. ( ( ph -> ps ) /\ ( ch -> th ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | onenotinotbothi.1 | |- -. ( ph -> ps ) |
|
| 2 | 1 | orci | |- ( -. ( ph -> ps ) \/ -. ( ch -> th ) ) |
| 3 | pm3.14 | |- ( ( -. ( ph -> ps ) \/ -. ( ch -> th ) ) -> -. ( ( ph -> ps ) /\ ( ch -> th ) ) ) |
|
| 4 | 2 3 | ax-mp | |- -. ( ( ph -> ps ) /\ ( ch -> th ) ) |