On The Absence Of Fawcett's Operations 1 and 6 In The Realisation Statements Of Halliday (1993)

Fawcett (2010: 182-3):

However, the most striking difference between the two sets of realisation operations is the omission from all three of the Sydney Grammar lists of our Operations 1 and 6. Operations 1 and 2 are in a sense the two fundamental operations, in that each adds one of the two major categories to the structure: Operation 1 adds a unit and Operation 2 an element. For example, the choice of the feature [situation] is realised by inserting the unit 'Cl' (for 'Clause'), and the choice of the feature [thing] is realised by inserting 'ngp' (for 'nominal group'). If there is no unit, there can logically be no elements, and so no structure. Thus the computer implementation of the Sydney Grammar must have such an operation, or it could not work. The odd thing is that it is not listed here. Operation 6 equally is crucial, because if the network is not re-entered only one layer of structure can be generated. 

The clue to the answer comes in Matthiessen and Bateman's description of what is covered by their term "preselection". For them, "preselections are instructions to re-enter the grammar to develop the function constituents of the clause as nominal groups, [...] and so on" (1991:108), so that their "Preselect" operation includes all three of (1) 'preselection' (in the strict sense of the term). (2) 're-entry' and (3) the insertion of a new unit. No doubt we can infer from this that Halliday's "preselect" operation includes the same three steps. 

Blogger Comments:

[1] To be clear, Fawcett's Operation 1 is 'Insert a unit (to fill an element)' (p180). In SFL Theory, a unit (clause, group, word, morpheme) is selected from the rank scale in a system network. SFL Theory models the phenomena of syntax as a rank scale. Fawcett's model of syntax (allegedly) does not include a rank scale.

[2] To be clear, Fawcett's Operation 6 is 'For an element, re-enter the system network' (p180). In SFL Theory, the selection of a given unit entails the selection of the features and the activation of realisation statements that specify all the elements of that unit. This includes structures that Fawcett regards as involving more than one "layer", such as clauses with textual and/or interpersonal Themes, where each is modelled as a simultaneous system within the network. Halliday & Matthiessen (2014: 162):

[3] This is misleading, because it is untrue; see [1] above. Halliday's (1995 [1993]: 273) realisation statement is not concerned with inserting a unit, but with preselecting a feature at a lower rank:

• 'Preselect' some feature at a lower rank (e.g., preselect actor : human collective);

[4] To be clear, Matthiessen & Bateman (1991) involves the adaptation of SFL Theory to the limitations of computers for the purposes of text generation. As such, it is not equivalent to the SFL model of the human use of language.