In a usual HMM process, a system finds the language sequence (i.e., state sequence) l m 1 that maximizes Equation (1) by typically using a Viterbi algorithm.
because large corpora are not always available, especially for minor languages, P (t i |l i ) is estimated using key entry sequence probabilities based on n-grams (with maximum n being n max ) as follows: and |t i | is the length of t i with respect to the key entry sequence.