For example, we consider that a CONTRAST relation holds between two text spans if one of the following relations holds: CONTRAST, ANTITHESIS, CONCESSION, or OTH-ERWISE, as defined by Mann and Thompson (1988), CONTRAST or VIOLATED EXPECTATION, as defined by Hobbs (1990), or any of the relations characterized by this regular expression of cognitive primitives, as defined by Knott and Sanders (1998) -NEGATIVE.
in our approach, we do not distinguish between contrasts of semantic and pragmatic nature, contrasts specific to violated expectations, etc.