AM as Sequence Tagging: We frame AM as the following sequence tagging problem.
each input token has an associated label from Y, where Y consists of all four-tuples (b, t, d, s) where b is a BIO encoding indicating whether the current token is non-argumentative (O) or begins (B) or continues (I) a component; t indicates the type of the component (claim C, premise P, or major claim MC for our data).