please answer with a proof sequence if valid if not prove that it is invalid. no truth tables

(4) (15 pts) Consider the following arguments. If an argument is valid, then present a proof sequence; otherwise, prove that the argument is invalid. You are forbidden to use truth tables to justify your answers (but, you may use them otherwise). (4a) (pr) A ()) ((PV9) r) (4b) (6-) A (p - (Vr))) (pr) (le) (P - (Ar)) (T) (s 0)) (t + p)