An upper bound on the zero-error list-coding capacity

Presents an upper bound on the zero-error list-coding capacity of discrete memoryless channels. Using this bound, we show that the list-3 capacity of the 4/3 channel is at most 0.3512 bits, improving the best previous bound. The relation of the bound to earlier similar bounds, in particular, to Korner's (1986) graph-entropy bound, is discussed.<
>