In the given grammar G, generate the simplified equivalent grammar by eliminating the following productions through (1)-(3). G = ({S, A, B, C, D}, {a, b, c, d), S, P) with productions SalaA|B|C. A gB. 2, B Aa, C CCD, D ddd | Cd (1) [5] Eliminate the -productions (2) [5] Eliminate the Unit-productions from (1) (3) [5] Eliminate the useless productions (2), so that give the simplified equivalent grammar. (4) [5] Give the language L that is generated by this grammar, L = L(G), in a formal expression (including a regular expression).