1. Given the following grammar: Expr -> + Expr Exper | * Expr Expr | 0 | 1 | | 9 |

Derive each of the follwing:

(a) + * 8 7 6

(b) + * * 7 6 5 4

2. Develop leftmost and rightmost derivations respectively for the Identifier value ab56c78, using the following BNF syntax:

Identifier -> Identifier { Letter | Digit } | Letter Letter -> a | b | | z | A | B | | Z Digit -> 0 | 1 | | 9