可不可以這樣用？以後有想到繼續補…

1.

Let X = (X₁, X₂, X₃, …, X_T) be a sequence of random variables in finite set of states
S = (S₁, S₂, S₃, …, S_N)

如果把X當成是term sequence，S可以是POS，concept or others

Reference: Part-of-speech tagging using a Variable Memory Markov model