Description: Conjoin antecedents and consequents in a deduction. (Contributed by NM, 3-Apr-1994) (Proof shortened by Wolf Lammen, 18-Dec-2013)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | anim12d.1 | |- ( ph -> ( ps -> ch ) ) |
|
| anim12d.2 | |- ( ph -> ( th -> ta ) ) |
||
| Assertion | anim12d | |- ( ph -> ( ( ps /\ th ) -> ( ch /\ ta ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | anim12d.1 | |- ( ph -> ( ps -> ch ) ) |
|
| 2 | anim12d.2 | |- ( ph -> ( th -> ta ) ) |
|
| 3 | idd | |- ( ph -> ( ( ch /\ ta ) -> ( ch /\ ta ) ) ) |
|
| 4 | 1 2 3 | syl2and | |- ( ph -> ( ( ps /\ th ) -> ( ch /\ ta ) ) ) |