Mistaking Thing For "Focus"

Martin (2013: 65):

Some examples [of Martin's Focus function] are given below.

Blogger Comments:

To be clear, analyses of these structures after Halliday (1985, 1994) have been inconsistent and even self-contradictory. For example, Halliday & Matthiessen (2004: 333, 2014: 394) write that the Thing

… is the entity that is functioning as participant in the transitivity structure of the clause …

If this principle is applied to the examples above, then six of the seven do not include a "Focus" function, as demonstrated by:

the front of the stage is wider than the back.
 an album is a collection of songs.
a chapter of the book was removed by censors.
the length of the stage is 9 metres
a Nobel Laureate is typically a genius of a writer
ragtime is a kind of jazz 

On the other hand, the coverage in Halliday (1985, 1994) is restricted to 'measure' expressions and 'facet' expressions, the latter being an optional alternative approach to Head/Thing conflation. The 'measure' expressions are analysed as complex Numeratives or Pre-Numeratives, and the 'facet' expressions as Pre-Deictics. Halliday (1994: 195-6):

Using the Halliday (1985, 1994) analysis:

the front of the stage is Pre-Deictic

a collection of songs is complex Numerative: collective

a chapter of the book is Pre-Numerative: partitive

three of the songs is Pre-Numerative: quantitive

the length of the stage is Thing

a genius of a writer is Thing

a kind of jazz is Thing

However, using the Halliday & Matthiessen (2004, 2014) analysis (see previous post):

the front of the stage is extended Numerative: partitive: facet

a collection of songs is extended Numerative: collective: aggregate

a chapter of the book is extended Numerative: partitive: portion

three of the songs is embedded Numerative

the length of the stage is Thing

a genius of a writer is Thing

a kind of jazz is extended Numerative: collective: variety