(25pt) Consider the following grammar, G, for conditional statements: 1. PS$ 6. U if C then S 2. SB 7. U if C then B else U 3. SU 8. Cci,i1 4. B if C then B else B9. Osi,i1 5. BO Nonterminals: P,S,B,U,C,O; terminals: if, then, else, ci,si,$ (a) (2pt) Show the parse tree of G for the input: if c1 then if c2 then s1 else if c3 then s2$. (b) (3pt) Compute First(X),FOLlow(X), for all nonterminals X, and PrediCt(p), for all productions p,1p9. (c) (5pt) Prove that G is not LL(1). Indicate all conflicts, that is, tokens belonging to two PREDICT(p) sets with the same LHS. (d) (10pt) Employ, on G, the techniques we used for attempting to make a grammar LL(1). Try to address all conflicts discovered at (c). (e) (5pt) Explain why it does not seem possible to obtain an LL(1) grammar