Description: Inference disjoining and conjoining the antecedents of two implications. (Contributed by Stefan Allan, 1-Nov-2008)
Ref | Expression | ||
---|---|---|---|
Hypotheses | jaao.1 | |- ( ph -> ( ps -> ch ) ) |
|
jaao.2 | |- ( th -> ( ta -> ch ) ) |
||
Assertion | jaoa | |- ( ( ph \/ th ) -> ( ( ps /\ ta ) -> ch ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | jaao.1 | |- ( ph -> ( ps -> ch ) ) |
|
2 | jaao.2 | |- ( th -> ( ta -> ch ) ) |
|
3 | 1 | adantrd | |- ( ph -> ( ( ps /\ ta ) -> ch ) ) |
4 | 2 | adantld | |- ( th -> ( ( ps /\ ta ) -> ch ) ) |
5 | 3 4 | jaoi | |- ( ( ph \/ th ) -> ( ( ps /\ ta ) -> ch ) ) |