Martin (1992: 156):
NEGOTIATION was approached from both a multivariate and covariate perspective in Chapter 2. The notion of constituency between exchange and move was developed to account synoptically for sequences of up to five moves. These moves are mutually predicting as set out in their constituency structures. … In addition, dependency structures were introduced to account for tracking and challenging moves which are not strongly predicted by initiations; indeed, interlocutors may formulate interacts so as to avoid them. … Reference structures make use of semantic dependency structures of this kind.
 This confuses multivariate structures (of a rank) with constituency (rank hierarchy). The constituency relation between exchange and move is the relation between levels in a rankscale. A multivariate structure, on the other hand, is 'a configuration of elements each having a distinct function with respect to the whole' (Halliday & Matthiessen 2004: 331). Further, as Halliday & Matthiessen (2004: 384) point out:
… 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.
 The use of dependency (logical metafunction) for NEGOTIATION (interpersonal metafunction) creates a theoretical inconsistency. It misconstrues interpersonal meaning as ideational meaning.
 The use of dependency (logical metafunction) for reference (textual metafunction) creates a theoretical inconsistency. It misconstrues textual meaning as ideational meaning.
 The dependency relations do not form structures; they merely obtain between units.