Then, A ∈ R |T |×|T | is a transition score matrix, A y i−1 ,y i is a transition 1 While<cite> (Ma and Hovy, 2016)</cite> define ϕ(yi−1, yi, oi) = exp(Wy i−1 ,y i oi + Ay i−1 ,y i ) as the potential function where W is the weight vector corresponding to label pair (yi−1, yi), we use the simple potential function here.