Formally, the sequence of labels is defined as: To define the scoring function f (h, y) for each position t, we multiply the hidden state h w t with a parameter vector w yt that is indexed by the tag y t to obtain the matrix of scores output by the bidirectional LSTM network.
the function f can be written as: In Equation 8, A is a matrix of transition scores, A i,j represents the score of a transition from the tag i to tag j, y 1 is the start tag of a sentence.