Martin (1992: 193):
Like temporal relations, external consequential relations are oriented to the activity sequences constituting fields; but the connections between events are "modulated" in such a way that one event is seen as enabling or determining the other rather than simply preceding it. All consequential relations have the experiential structure Cause · Effect.
 This confuses the ideational system of enhancement with the interpersonal system of modality. The ideational metafunction is concerned with the construal of experience as meaning, whereas the interpersonal metafunction is concerned with the enactment of the self as meaning. These are distinct complementary functions in the SFL model.
 Here again an experiential structure is proposed for a logical structure at the level of discourse semantics.