We can see that while increasing the n-gram model size, our method (ARS) exhibits a linear increase in decoding time, in contrast to the exponential factor exhibited when running the Viterbi algorithm over the full WFSA (F).
finally in both figs 4c and 4d, we show the average number of iterations taken to sample from the entire test-test, and the average number of states in our variable-order HMMs, with AR-100=60%.