Halliday & Matthiessen (2014: 451):
… the relationships among the elements in a multivariate structure can be characterised as segmental from an experiential point of view but as prosodic from an interpersonal point of view and as cumulative from a textual one. A prototypical example of a segmental structure is the transitivity structure of a clause, a prototypical example of a prosodic structure is the tone contour that typically extends over a clause, and a prototypical example of a culminative structure is thematic prominence at the beginning of the clause (followed by rhematic non-prominence).