Problem 4 Show that the following grammar is ambiguous. - ab -- Empty --b Empty Consider aaabb: Problem 5 Rewrite the following grammar to give + precedence over * and force * to be right associative. = ABC + * + () Consider the following Grammar: = ABC + | * | + () Problem 6 Rewrite the BNF of this grammar to add the ++ and -- unary operators of Java. Problem 7 Using the grammar given above, show a leftmost derivation for the following statement: A=B* (C* (A + B)