Since a cell may represent an empty word, a cell sequence may represent an n-gram where We denote |S(i, i )| to be the length of n-gram represented by a particular cell sequence S(i, i ).
all the cell sequences S(i, i ) can be classified, with respect to the length of corresponding n-grams, into a set of parameters where each element (with a particular value of n) has the probability The probability of the transition from i to i is: the transition probability of incremental IHMM is a weighted sum of probabilities of 'ngram jumping', defined as conventional IHMM distortion probabilities.