On asymptotically optimal sequential lossless coding for memoryless switching sources

Two strategies are used to exploit a set D_n of dormant nodes. The first creates σ nodes each time a new node should be created. One node with reset occurrence counts, while the others assume counts of all dormant nodes. When sufficient data is available, all new nodes but the one that is likely to represent a true state are eliminated. The second strategy creates only one instance, but when sufficient data is available, the occurrence counts of the new node are changed to those of the most likely dormant state, if such exists. If some mild regularity conditions hold, and only the most recent σ states may repeat, both strategies are asymptotically optimal. In practice, the strategies vary in complexity and performance.