2. [10 Points] Consider the following grammar: Kassi kid> expr Kid I C expr l kid> . Show aparse tree and leftmost derivation forthe following statements: (a) A A (B (C A) (b) A A (B+ C) 3. [10 Points Show that the following grammar is ambiguous Kid 4. [10 Points] Compute the weakest precondition foreach of the following assignment statements with their given postconditions (a) a 2 (b 1) 1 fa 0) (b) a a 2 b 1 1