Martin (1992: 293-4):
The network for lexical relations developed below will be organised around these three different aspects of the contextual structure of activity sequences. … At primary delicacy, the system for lexical relations is presented as Fig. 5.10.
There are two major violations of the stratification hierarchy here.
 On the one hand, lexical relations (lexicogrammatical stratum) are presented as being a system of a higher stratum (discourse semantics).
 On the other hand, while the system is presented as located on the discourse semantic stratum, it is actually composed of the features that have been argued to be located at the stratum of context: (taxonomic, nuclear and activity).
The system proposed for the discourse semantic stratum is concerned with the stratum below (lexicogrammar) and composed of features purported to be of the stratum above (context).