Description: A deduction based on modus ponens. (Contributed by NM, 12-Dec-2004) (Proof shortened by Wolf Lammen, 7-Apr-2013)
Ref | Expression | ||
---|---|---|---|
Hypotheses | mpand.1 | |- ( ph -> ps ) |
|
mpand.2 | |- ( ph -> ( ( ps /\ ch ) -> th ) ) |
||
Assertion | mpand | |- ( ph -> ( ch -> th ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | mpand.1 | |- ( ph -> ps ) |
|
2 | mpand.2 | |- ( ph -> ( ( ps /\ ch ) -> th ) ) |
|
3 | 2 | ancomsd | |- ( ph -> ( ( ch /\ ps ) -> th ) ) |
4 | 1 3 | mpan2d | |- ( ph -> ( ch -> th ) ) |