Martin (1992: 520):
The oppositions relevant to field-structured texts are elaborated systemically in Fig. 7.10. Texts accompanying a social process are distinguished from those constituting one.
Fig. 7.10. Mode — degrees of abstraction
 The intellectual source of the most general opposition in this system is Hasan (1985/9: 58), where the features are termed ancillary and constitutive, and the system is termed language rôle, one of three systems within mode, the system of the textual metafunction at the level of context.
 The use of the word 'texts' here betrays the ongoing confusion between text type/register and context (mode). The confusion is thus along two theoretical dimensions simultaneously: stratification (context vs language) and instantiation (system vs instance type/subpotential).
 As previously explained, there are no "degrees of abstraction" here. On the basis of this and numerous previous critiques, it is fair to say that the notion of abstraction is not understood.
Problems with the network itself will be identified in the following posts.