Изменения

probabilities[s, t] = (alpha(s, t) * beta(s, t)) / chain_probability

* [[wikipedia:Forward–backward_algorithm|Wikipedia {{---}} Forward–backward algorithm]]

* [http://web.cecs.pdx.edu/~mperkows/JUNE1a/010.Intorduction-to-HMM.ppt|Forward/Backward Algorithms for Hidden Markov Models]