Description: Eliminate the right side of a negated conjunction in an implication. (Contributed by ML, 17-Oct-2020)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | mpnanrd.1 | |- ( ph -> ps ) | |
| mpnanrd.2 | |- ( ph -> -. ( ps /\ ch ) ) | ||
| Assertion | mpnanrd | |- ( ph -> -. ch ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | mpnanrd.1 | |- ( ph -> ps ) | |
| 2 | mpnanrd.2 | |- ( ph -> -. ( ps /\ ch ) ) | |
| 3 | imnan | |- ( ( ps -> -. ch ) <-> -. ( ps /\ ch ) ) | |
| 4 | 2 3 | sylibr | |- ( ph -> ( ps -> -. ch ) ) | 
| 5 | 1 4 | mpd | |- ( ph -> -. ch ) |