The three factors that are multiplied in Eq. 8.19 for extending the previous paths to compute the Viterbi probability at time t are .11 A sketch of the lattice for Janet will back the bill, showing the possible tags (q i ) for each word and highlighting the path corresponding to the correct tag sequence through the hidden states. States (parts of speech) which have a zero probability of generating a particular word according to the B matrix (such as the probability that a determiner DT will be realized as Janet) are greyed out.