Prove the following using deductive tableaux: a. (p (q r)) rightarrow ((p q) (p r)) b. ((A rightarrow B) rightarrow A) rightarrow A Prove the following tableaux: T superset (U superset V) T superset U Prove the following using deductive tableaux: a. (p (q r)) rightarrow ((p q) (p r)) b. ((A rightarrow B) rightarrow A) rightarrow A Prove the following tableaux: T superset (U superset V) T superset U