On Halliday's And Fawcett's Versions Of Halliday's Theory Sharing The Same General Framework

Fawcett (2010: 91):

There would be widespread agreement among systemic functional linguists — and especially among those who are interested in the theoretical-generative strand of work in SFL — that "Systemic theory" provides an excellent (though necessarily highly compressed) summary of the essential concepts of Halliday's SF grammar. Indeed, the model described in Chapter 3 and summarised in Figure 4 (in Section 3.2 of that chapter) can be seen as an alternative statement of broadly the same set of concepts — subject to the qualifications expressed above and in Section 4.7 of Chapter 4. 

From the viewpoint of the topic of this book, this difference is not crucial, since we are focussing here on the theory of syntax, i.e., the theory of both the potential and the instances at the level of form. In Section 4.6 of Chapter 4 we established that the difference between the levels of the system networks in the Sydney and the Cardiff versions of SFL, while significant in some cases, did not invalidate the view that the two share the same general framework, and this view is supported by the broad similarity between the 'realisation operations' in the two frameworks that we have noted. This means that we are indeed in a position to make a direct comparison between the theories of syntax presented in each of the two theories. 

However, from this last perspective "Systemic theory" has one great weakness. This is that it does not provide a specification of the "basic concepts" of the part of the theory whose task it is to account for the status of the instances at the level of form. It is these concepts with which IFG is concerned.

Blogger Comments:

[1] This is misleading, because it is untrue.  As previously demonstrated, Fawcett's model (Figure 4) is not only inconsistent with Halliday's theory, it is invalidated by its own internal inconsistencies, including the confusion of axial realisation with instantiation.

[2] To be clear, a systemic-functional theory, by definition, gives priority to system and function over syntagm and form.  In Halliday's theory, grammatical form is modelled as the rank scale, with each rank as the entry condition for grammatical functions.

[3] To be clear, Fawcett's potential at the level of form includes functions in realisation rules, and his instances at the level of form are the realisation of these functions in structures.

[4] This misleading.  The view that Fawcett's theorising is of the same general framework, SFL, is not at issue.  What is at issue is if Fawcett's version of Halliday's theory is itself valid, both in terms of SFL theory and in terms of internal consistency.

[5] To be clear, in Halliday's version of his own theory, realisation statements are located in system networks at the levels (strata) of semantics, lexicogrammar and phonology.  In Fawcett's version of Halliday's theory, realisation operations are located only at one of two levels, the level of form, which is, incongruously, a lower level of abstraction than the systemic features to which they apply.  Moreover, Fawcett's realisation operations are incongruously held to specify instances, rather than realisations.

[6] This is misleading, because it is untrue.  Halliday's theory is not a theory of syntax.  Halliday (1985/1994: xiv):

[7] This is misleading, because it is untrue.  To be clear, 'instances at the level of form' do not feature in Halliday's theory, and so their theoretical status in Halliday's model does not need to be accounted for. However, since Fawcett's 'instances of form' translates to 'structures' in Halliday's theory, Halliday (1993) identifies syntagmatic structure as the realisation of paradigmatic system, with the basic concept of realisation statements in systems specifying structural realisations.  Halliday (1995 [1993]: 272):

The system has one further component, namely the 'realisation statement' that accompanies each option. This specifies the contribution made by that option to the structural configuration; it may be read as a proposition about the structural constraints associated with the option in question.

Falsely Presenting A Non-Sequitur As A Conclusion Of Two False Propositions

Fawcett (2010: 90-1):

Let us now summarise the place in "Systemic theory" of the more specifically 'structural' concepts from "Categories". The categories of 'unit', 'class (of unit)' and 'element' are not included in the presentation of the "basic concepts". Moreover, while the term "element" is used in presenting the realisation statements, it has a different sense from that in "Categories". 

On the other hand, "Systemic theory" includes a set of seven 'realisation operations'. While the latter are related to the "categories" that are missing in "Systemic theory" — in the sense that they generate the structures that exemplify the missing categories — the relationship is not self-evident. In Section 9.2.1 of Chapter 9 we shall see exactly how a revised set of realisation operations can generate all of the specific categories and relationships that are needed to specify the instances at the level of form in a modern systemic functional grammar.

Thus two sets of concepts are required in a full theory of syntax: (1) the theoretical concepts that specify the syntax potential, and (2) the theoretical concepts that specify the instances. The theory of 'syntax potential' will be presented and discussed in Chapter 9 of Part 2, and the theory of 'instances of syntax' will be set out in Chapters 10 and 11.

Blogger Comments:

[1] This is misleading, because it is untrue.  As previously demonstrated, Halliday's term 'element' retains the same meaning across the two theories, and Fawcett's misunderstanding on the matter arises from confusing 'element' with 'constituent'.

[2] This is misleading, because it is untrue.  As previously demonstrated, the "categories" that Fawcett mistakenly thinks are missing in Halliday (1993) are those that serve as the entry conditions to the systems at each rank: clause, group/phrase, word and morpheme.

[3] To be clear, Fawcett's 'instances of form' (in Figure 4) refers to 'one layer of a richly labelled tree structure'.  As previously noted, this confuses instance (of potential) with the structure (realising system).

[4] This is misleading, because it falsely presents this non-sequitur as a conclusion entailed by the preceding discussion.

[5] To be clear, Fawcett (p172) identifies 'syntax potential' as part of 'form potential', which, in turn, he (p36) identifies as 'realisation rules/statements' (Figure 4).  However, it turns out (p175) that 'realisation operations' and 'potential structures' are the two parts of 'syntax potential'.  This compositional inversion will be examined further in the analysis of Fawcett's Chapter 9.

Misrepresenting Halliday (1993) On Realisation And Instantiation

Fawcett (2010: 90):

Let me summarise the "basic concepts' of "Systemic theory". These are: 'system', 'system network', 'selection expression', 'realisation' and 'structure' — the latter, however, only being used in a highly generalised sense. In addition, Halliday makes a fundamental distinction between 'realisation' and 'instantiation', exactly as we have done as in Chapter 3. However, he then he goes on to blur the distinction by saying that the term "realisation" is not only used for "the relation between strata" but also, "by analogy", for "the relation between the paradigmatic and the syntagmatic phases of representation within one stratum". I find this an unfortunate formulation, because it suggests that there is an immediate relationship between the system networks ("the paradigmatic [...] phase") and the output structure ("the [...] syntagmatic phase"). In other words, this way of describing matters overlooks (1) the relation of instantiation between the system networks and the selection expression, (2) the selection expression itself, (3) the realisation rules (which are triggered by the features in the selection expression), and finally (4) instantiation relation between these and the output structures that they generate. In other words, at this point in "Systemic theory" Halliday's second view of 'meaning' (as described in Section 4.6 of Chapter 4) appears to be dominant — i.e., the one in which the system networks are assumed to be at the same level as the final output structures. Apart from this short passage, however, the theoretical model of language presented in "Systemic theory", with its two components of the system networks and the realisation statements, is essentially the same as the general systemic functional model proposed in Chapter 3.

Blogger Comments:

[1] To be clear, Halliday (1995[1993]: 272-3) presents the system, which includes realisation statements and selection expressions, as the basic concept of Systemic theory, and lists rank, realisation (stratal and axial), delicacy, instantiation and metafunction as the other basic concepts.  Structure, on the other hand, is only mentioned in relation to metafunction:

These metafunctions define the dimensions of semantic space; and since they tend to be realised by different structural resources — experiential meanings segmentally, interpersonal meanings prosodically, logical meanings in iterative structures, and textual meanings in wavelike patterns …

[2] This is misleading, because it is untrue.  As previously demonstrated, Fawcett's model (Figure 4) confuses the realisation relation between system and structure with the instantiation relation between potential and instance; see further below.

[3] This is misleading, because it is untrue.  It is Fawcett who "blurs the distinction", not Halliday.  The relation between the paradigmatic axis (system) and the syntagmatic axis (structure) is realisation, not instantiation.  Instantiation, on the other hand, is the relation between potential (system) and instance (text).

[4] To be clear, this is neither unfortunate, nor a suggestion.  It is a statement about the architecture of Systemic theory: paradigmatic systems are realised by syntagmatic structures.

[5] These four claims are misleading, because they are untrue.

• A selection expression is not an instance of system; it is the bundle of features that define a unit, whether as potential or instance, as in the case of the features [voiceless, velar, stop] defining the phoneme /k/, as potential or instance.
• As such, a selection expression is irrelevant to both instantiation and axial realisation.
• Realisation statements are activated by feature selection, not selection expressions.  Here Fawcett is presenting his own logically-inconsistent model as the benchmark for assessing Halliday's.
• The relation between realisation rules and the structures they generate is, as the name implies, realisation, not instantiation.

[6] This is misleading, because it is untrue.  Halliday has one view on meaning.  As previously demonstrated, Fawcett's misunderstanding on the matter derives from his confusing meaning potential (language as system) with meaning (the stratum of semantics).

[7] This is misleading, because it is untrue.  Moreover, it is contradicted by Fawcett's own report (above) of Halliday (1993):

"realisation" is not only used for "the relation between strata" but also, "by analogy", for "the relation between the paradigmatic and the syntagmatic phases of representation within one stratum".

Clearly, Fawcett does not understand that realisation is a relation between different levels of symbolic abstraction.

[8] This is very serious misrepresentation indeed.  As previously demonstrated, Fawcett's model (Figure 4) is not only inconsistent with Halliday's theory, it is internally inconsistent, as shown again here, where Fawcett presents selection expressions as instance of systems, and syntagmatic structures as instances of realisation rules.

Misrepresenting Halliday On Semantics

Fawcett (2010: 89-90):

One reason may be that he was not sufficiently confident of its place [i.e. the semantic stratum] in the overall theory at the time of writing "Systemic theory" to give it this status. Another possible reason may be that he limited himself, in what was necessarily a short paper, to just those concepts that he believed to be common to all 'dialects' of SFL. In other words, he may have omitted the concept of a 'higher semantics' on the grounds that some other systemic functional linguists (including those working in the framework of the Cardiff Grammar) consider that the existing system networks (or replacements for them that are more explicitly semantic) are all that is needed to model those aspects of 'meaning' that it is appropriate to model as lying within language. Either way, the absence of this concept from this key summary of the theory seems to signal that at the time of writing Halliday was less confident of its centrality in his view of language than he appears to have become in subsequent works, such as Halliday & Matthiessen (1999).

Blogger Comments:

[1] This is misleading, because it is untrue.  The "subsequent" work, Halliday & Matthiessen (1999), was first conceived between 1980 and 1983 when Matthiessen was a research assistant at the Information Sciences Institute at the University of Southern California, more than a decade before Halliday (1993). Halliday & Matthiessen (1999: ix):

This book was conceived dialogically: it started as notes on discussions between the two authors when CM was working at the University of Southern California's Information Sciences Institute and MAKH was visiting there as a consultant.

 Moreover, Fawcett was the series editor for the publication.

[2] This is misleading.  Here Fawcett has falsely attributed his own view on the matter to Halliday.

[3] This is misleading, because it is untrue, as demonstrated in the previous post.

Misrepresenting Halliday (1993) On Semantics

Fawcett (2010: 89):

We have already noted several surprising omissions of "Categories" concepts from the basic concepts of "Systemic theory". I shall now identify another omission — though it is one of a different sort. You will recall, from Section 4.6 of Chapter 4, that in recent years Halliday has shown an increasing commitment the view that we should recognise an additional layer of 'meaning potential' — i.e., a 'semantics' above the level of 'meaning potential' that is represented in the system networks for TRANSITIVITY, MOOD and so on. We called this the 'two-level' model of meaning. Interestingly, Halliday does not include this concept in "Systemic theory". If it is as central to his view of language as some of his recent writings suggest (e.g., 1996:29), why, one wonders, has it been left out?

Blogger Comments:

[1] See the preceding posts for the invalidity of this claim.

[2] This is misleading, because it is untrue.  As previously demonstrated, the stratification of the content plane into semantics and lexicogrammar has been a feature of SFL theory at least since Halliday & Hasan (1976), if not before.

[3] As previously demonstrated, Fawcett confuses 'meaning potential' (language as system) with the stratum of meaning (semantics).  Here he compounds the misunderstanding by confusing it with the stratum of wording (lexicogrammar).

[4] To be clear, it is the content plane that is stratified, with one level of meaning and one level of wording.

[5] This is misleading.  Halliday (1995 [1993]: 273) writes:

The shift to a paradigmatic orientation led to the finding that the content plane of a language is organised in a small number of functionally defined components which Halliday labelled 'metafunctions.' … The stratal role of the lexicogrammar lies in mapping these semantic components into a unitary construct, one that is capable of being linearised.

On The Strange Omission Of The Vital Operation 'Insert Unit'

Fawcett (2010: 88):

Strangely, one vital operation appears to be missing from Halliday's list in "Systemic theory" — and it is also missing from the closely related lists given in Matthiessen & Bateman (1991) and Matthiessen (1995). This missing operation is 'Insert unit', and I shall comment on the possible reasons for its absence in Section 9.2 of Chapter 9.

Blogger Comments:

To be clear, Fawcett's operation 'Insert unit' corresponds to Halliday's features of the rank scale — clause, group/phrase, word, morpheme — as the entry conditions for more delicate systems at each rank, as will be seen in the examination of Section 9.2 of Chapter 9.  Fawcett's model lacks a rank scale, and so requires this extra 'operation' in his inventory of realisation rules. It will also be seen in that future discussion that Fawcett continues his previously identified confusion of structure with constituency.

Misrepresenting Halliday (1993) By Confusing Rank With Structure

Fawcett (2010: 88n):

You may have noticed that the term "rank" is used in (f) above, but this is not significant. This is because, strictly speaking, Halliday should have used here a term such as "layer of structure" or "unit", since the unit that is 'lower' in the structure is not necessarily of a lower 'rank' (e.g., a clause or a prepositional group/phrase frequently functions as a qualifier in a nominal group).

Blogger Comments:

Reminder:

(f) 'Preselect' some feature at a lower rank (e.g., preselect nominal group);

This is misleading, because it is untrue. Here Fawcett's wording "lower in the structure" confuses the rank scale of forms ("lower") with the syntagmatic axis ("structure").  The form that realises a function is not lower in structure, but lower in constituency.  In the case of a clause realising the Qualifier of a nominal group, the (higher rank) clause is a constituent of a (lower rank) nominal group, which is why the phenomenon is called 'rankshift'.

Misrepresenting Halliday (1961, 1993) And Matthiessen (1995) On Element

Fawcett (2010: 88):

In the Sydney Grammar, it is the word "function" that should, strictly speaking, be used to refer to concepts such as 'Subject' and 'Theme', e.g., in (a), (b) and (c) of Halliday's realisation statements. The term "element" is typically used for the component of the clause into which such "functions" combine. Interestingly, Matthiessen makes no use at all of the term "element", using instead the informal term "bundle of functions". Thus in "Systemic theory" Halliday uses "element" in Matthiessen's sense of "function" — such that the "conflation" (or 'fusion') of two or more such "functions" combines to constitute a single element of the clause, in the way to be described in Section 7.2 of Chapter 7. It is this unified sense of "element" that corresponds most closely to the meaning of the term "element" in "Categories". It may be thought that this is not a major difference, but it is nonetheless a significant one, because it reflects the addition to the theory of the concept that an element may carry several meanings at the same time — this being the third of the major developments in the theory that we noted in Chapter 4.

Blogger Comments:

[1] This is misleading, because it is untrue.  Subject and Theme are each elements of function structure.  In theoretical terms, this specifies them as located on the syntagmatic axis, whereas the unqualified term 'function' does not.  For example, as Halliday & Matthiessen (2014: 83) point out: 'Theme functions in the structure of the clause as message'.

[2] This is misleading, because it is untrue.  Elements of function structure, such as Subject and Location, map onto clause constituents, such as nominal groups and prepositional phrases.  That is to say, here Fawcett has merely confused the term 'element' (of function structure) with the term 'constituent' (as modelled by the rank scale of form).  Halliday & Matthiessen (2014: 9):

Grammatically, however, the constituent of a clause is not, in fact, a word; it is either a phrase or a word group…

[3] To be clear, the terms 'element' and 'bundle of functions' are not synonymous.  While an element is a structural function such as Theme or Subject or Senser, a bundle of functions are all the structural functions that map onto a clause constituent, such as Theme and Subject and Senser all mapping onto a nominal group.

[4] This is doubly misleading, because it is doubly untrue. On the one hand, in Halliday's Scale and Category Grammar (1961), before the theorising of metafunctions, there are no functions to be conflated on a constituent, and on the other hand, Halliday (1961) uses the term in precisely the same way as in Systemic Theory (1993).  Halliday (2002 [1961]: 47):

In the statement of English clause structure, for example, four elements are needed, for which the widely accepted terms subject, predicator, complement and adjunct are appropriate.

Misrepresenting Halliday (1985, 1993, 1994) And Matthiessen (1995) On Element

Fawcett (2010: 87-8):

Halliday's seven types of 'realisation statement' are, in his words:

(a) 'Insert' an element (e.g., insert subject); 

(b) 'Conflate' one element with another (e.g., conflate subject with theme); 

(c) Order' an element with respect to another, or to some defined location (e.g., order finite auxiliary before subject); 

(d) 'Classify' an element (e.g., classify process as mental: cognition); 

(e) "Split' an element into a further configuration (e.g., split mood into subject + finite); 

(f) 'Preselect' some feature at a lower rank (e.g., preselect nominal group); 

(g) 'Lexify' an element (e.g., lexify subject : it). 

(Halliday 1993:4505) 

… Earlier, we were considering the fact that the concept of 'element' was not presented as a "basic concept" in "Systemic theory". However, as you can see from the number of instances of the word "element" in boldface in Halliday's realisation statements, this term certainly plays a central role in the process of building 'structure' in his theory. Notice, however, that the term "element" is being used here in a different sense from that in "Categories" — and also from that in which it is typically used in IFG and in Matthiessen (1995:23-5).

Blogger Comments:

[1] This is misleading, because it is untrue.  Despite the fact that the two publications outline different theories,  the use of the term 'element' in Halliday (1993) is the same as its use in Halliday (1961), as the following quote from "Categories" (Halliday 2002 [1961]: 46-7) makes plain:

A structure is made up of elements which are graphically represented as being in linear progression; but the theoretical relation among them is one of order. … A structure is thus an arrangement of elements ordered in places. Places are distinguished by order alone: a structure XXX consists of three places. … In the statement of English clause structure, for example, four elements are needed, for which the widely accepted terms subject, predicator, complement and adjunct are appropriate. These yield four distinct symbols, so that S, P, C, A would be the inventory of elements of English clause structure.

What differs in the two theories is that "Categories" (Halliday 1961) does not yet differentiate between metafunctions, and so the elements of structure are restricted to what later became those of the interpersonal metafunction in Systemic Theory.

[2] This is misleading, because it is untrue.  The meaning of 'element' in both IFG and Matthiessen (1995) is 'structural function'.  For example, Halliday (1985: 32; 1994: 30) writes:

…each clause contains one element which can be identified as its Subject…

It will be seen in the following post that Fawcett confuses (functional) 'element' with (formal) 'constituent'.

On There Being No Important Difference Between The Terms 'Realisation Statements' And 'Realisation Rules'

Fawcett (2010: 86n-7n):

Halliday prefers the term 'statements' to rules', but there is no difference of substance here. Following Hudson's pioneering work on realisation in Hudson (1971), I use the term "realisation rules". Strictly speaking, what Halliday refers to here as "realisation statements" are 'realisation operations', because it is possible for the realisation statement for a given feature to include two or more such 'operations'.

Blogger Comments:

[1] This is misleading, because it is untrue.  On the one hand, Halliday's term 'realisation statement' is consistent with the notion of systems as probabilistic, since probability is a modality of statements. 

On the other hand, Fawcett's term 'realisation rules' construes commands, the agnate modality of which is obligation. This is inconsistent with both modelling systems as probabilistic and with the fundamental view of language taken by SFL theory: meaning as choice.

[2] To be clear, this is a non-sequitur.  Fawcett's argument is as follows:

Premiss: a realisation statement for a feature can include two or more operations,
Conclusion: realisation statements should be called realisation operations.

On the one hand, the Premiss is false, because, in Halliday's model, each individual realisation statement constitutes only one 'operation', not two or more.  On the other hand, the reasoning of the argument is invalid because it deploys the type of circular reasoning known as 'begging the question' (petitio principii), wherein the truth of the conclusion is assumed in the premiss, namely: that realisation statements are operations.

On The Location Of Halliday's Realisation Statements In Fawcett's Model

Fawcett (2010: 86-7):

The selection expression is the input to the realisation statements. The function of each of these is to specify, for a given feature in the system network, the operation through which that feature contributes to "the structural configuration" that is being generated. In "Systemic theory" Halliday specifies seven types of realisation statement, his claim being that every such statement conforms to one of the seven types. As we saw in Chapter 3, a theory of syntax must be concerned with how the grammar specifies both (1) the syntax potential and (2) the instances of syntax, i.e., the outputs from the grammar. In terms of Figure 4 in Chapter 3, then, Halliday's 'realisation statements' belong in the box labelled "realisation rules / statements".

I shall now list the set of types of 'realisation operation' given in "Systemic theory". However, I shall leave the full explanation and evaluation of each to Chapter 9 of Part 2, because they are relatively close to the set that is required for this component of a modern theory of syntax for a SF grammar — though the set to be introduced in Chapter 9 set is slightly fuller. They will therefore be explained and evaluated at that point, i.e., in Section 9.2.1 of Chapter 9.

Blogger Comments:

[1] To be clear, here Fawcett has momentarily switched from his red herring argument, of assessing Halliday (1993) in terms of Halliday (1961), to merely restating where Halliday's realisation statements are located in his own model (Figure 4), which, as previously explained over and over (e.g here), is riddled with internal inconsistencies that result from his theoretical misunderstandings.

[2] Here, once again, Fawcett primes the uncritical reader by promising a critique ('evaluation') elsewhere.

Misconstruing Selection Expressions As Instances Of Meaning

Fawcett (2010: 86):

Let us begin with instantiation. In Halliday's words: 

'Instantiation' is the relation between the semiotic system and the observable events, or 'acts of meaning'. (Halliday 1993:4505)

Even a selection expression, which is strictly speaking not "observable", is an 'instance', i.e., an 'instance of meaning', in that it is the set of features that have been chosen on one traversal of the system network. Thus the instance of meaning' chosen in Section 3 of the worked example in Appendix A is: 

[thing, count, plural, student, nearness to performer, un-near]

Blogger Comments:

[1] This is misleading, because it is not true.  A selection expression is the systemic classification of a given unit.  Halliday (1993: 273):

The selection expression constitutes the grammar's description of the item (e.g., the particular clause so specified); it is also, by reference to the network, the representation of its systemic relationship to other items in the language — since the grammar is paradigmatic, describing something 'consists in' locating it with respect to the rest (showing its total lineage of agnate forms).

Importantly, this may be the unit as potential, unit as instance, or unit as somewhere between (as sub-potential or instance type).  For example, the selection expression of a phoneme, such as [voiced, velar, stop], may describe it as phonological potential or as an actual instance when spoken.

To be clear, this misunderstanding is fundamental to Fawcett's model (Figure 4), and, as a misunderstanding, constitutes one of the lines of evidence that invalidates it.

[2] To be clear, here Fawcett confuses language ("observable") with the linguistic description of it (selection expression).  That is, he confuses the data with the model.

[3] To be clear, selection expressions are relevant in Systemic theory wherever there are systems, and thus are not limited to the level of meaning, semantics.  This is only the case in Fawcett's model, where they are misunderstood as instances.

Misrepresenting Halliday (1993) On Realisation

Fawcett (2010: 85-6):

Finally, let us look at what has happened to the term realisation (Halliday's 1966 replacement for the original "Categories" term "exponence"). Halliday originally brought the concept of 'realisation' into use as a result of the elevation of 'system' to model 'meaning potential', as we saw in Figure 4 (in Section 3.2 of Chapter 3). However, the original "Categories" concept of 'exponence / realisation' has now become the concept that denotes the relationship between two levels of language. In Halliday's words:

'Realisation' is the relationship between the 'strata' (or levels) of a [...] semiotic system" (Halliday (1993:4505).

Thus the term has significantly changed its meaning as a result of the elevation of 'system' to model 'meaning potential', just as 'system' itself and 'delicacy' have — but in this case the change of meaning has been marked by a change of name.

Blogger Comments:

[1] To be clear, here Fawcett claims the meaning (Value) of a term 'realisation' has changed despite the fact that it is actually the term (Token) that has changed (from 'exponence'), not the meaning.

[2] This is misleading, because it is untrue.  Halliday adopted the term 'realisation' as the name for the relation between levels of symbolic abstraction, in the first instance, between strata.  As previously demonstrated, Fawcett's notion of 'the elevation of system to model meaning potential' confuses language as potential (system) with the semantic stratum (meaning).  Moreover, the fact that this is irrelevant to the notion of 'realisation' demonstrates that Fawcett does not understand the meaning of this theoretical term.

As the grammar makes plain, 'realisation' is a nominalisation of the intensive identifying Process 'realise' which relates a less abstract (lower level) Token to a more abstract (higher level) Value.

[3] This is misleading, because it is untrue.  Fawcett's own model (Figure 4) says nothing about changes to Halliday's model, actual or imaginary, even when the latter is understood.

[4] This is misleading, because it is untrue.  As demonstrated in previous posts, the terms 'system' (evidence here) and 'delicacy' (evidence here) have not changed their meaning.

More importantly, the meanings of terms in one theory, Scale & Category Grammar (Halliday 1961), are irrelevant to an examination of another theory, Systemic Theory (Halliday 1993).  Fawcett's entire enterprise in comparing terms across theories is an instance of the Red Herring logical fallacy.