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 ) )  |