On minimal redundancy codes.
A code X over the alphabet A is complete if the submonoid X* generated by X meets all two-sided ideals of A*. If one measures the cost of a finite code X over A, with respect to a given information source S, by the quantity gamma(X) = <X> ln |A|, we say that X is completely optimal for S if it does not exist any code X', over an arbitrary alphabet, such that gamma (X') < gamma (X). One can show that for |X| ≤ 5 a completely optimal code has to be complete. However for |X| >...