Description: An inference based on modus ponens. (Contributed by NM, 23-May-1999) (Proof shortened by Wolf Lammen, 22-Nov-2012)
Ref | Expression | ||
---|---|---|---|
Hypotheses | mpdan.1 | |- ( ph -> ps ) |
|
mpdan.2 | |- ( ( ph /\ ps ) -> ch ) |
||
Assertion | mpdan | |- ( ph -> ch ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | mpdan.1 | |- ( ph -> ps ) |
|
2 | mpdan.2 | |- ( ( ph /\ ps ) -> ch ) |
|
3 | id | |- ( ph -> ph ) |
|
4 | 3 1 2 | syl2anc | |- ( ph -> ch ) |