Martin (1992: 314-5):
Next, extension. With extension distinct meanings are combined. The contrast between Process°Range:process and Process°Medium structures in the clause, and Classifier°Thing and Epithet°Thing structures in the nominal group has already served to illustrate the difference between elaboration and extension at issue here. Where Range:processes elaborate a Process, Range:entities (Halliday 1985: 134-5) and Mediums (Halliday 1985: 144-5) extend them as outlined in Table 5.11.
Blogger Comments:
[1] Extension, like elaboration, enhancement and projection, is a logico-semantic relation. It includes the relations of composition (meronymy), possession and association.
[2] As previously demonstrated (here and here), it is not the case that 'the contrast between Process°Range:process and Process°Medium structures in the clause, and Classifier°Thing and Epithet°Thing structures in the nominal group has already served to illustrate the difference between elaboration and extension at issue here'. (Process and Medium are not related by extension; in the examples provided, both Classifier and Epithet elaborate the Thing.)
[3] Neither Range:entities nor Mediums extend a Process. On the one hand, in SFL, expansion and projection relations obtain between the Nucleus (Process/Medium) and the rest. On the other hand, the relation between the Nucleus and Range:entity depends on the process type. In material processes, the relation is enhancement, not extension. In mental and verbal processes, the relation is projection, not extension. See Halliday & Matthiessen (1999: 175).
Thus, none of the six examples involve extension. In the first three, the relation is enhancement, not extension, whereas in the last three, it is projection, not extension.
[4] 'Tennis' and 'play' are processes, not entities. Martin (1992: 311):
As Halliday (1985: 135) points out, "Tennis is clearly not an entity; there is no such thing as tennis other than the act of playing it."
