Consider the following grammar: rightarrow = rightarrow A | B | C rightarrow + | * | () | Show a parse tree and leftmost derivation for the following statements: A = A + (B * (C + A)) A = A * (B + C) Show that the following grammar is ambiguous. rightarrow rightarrow + | rightarrow a | b | c Compute the weakest precondition for each of the following assignment statements with their given postconditions. a = 2 * (b - 1) - 1 {a > 0} a = a + 2 * b - 1 {a > 1)