Syllable structure

 

We will assume that words have a phonological structure consisting of a sequence of syllables, each syllable having the simplified structure shown below:

  

Figure 2: Syllable structure

Such syllabic structures are readily defined by means of simple context-free phrase structure rules:

syllable $\rightarrow$ onset peak coda
disyllable $\rightarrow$ syllable syllable
trisyllable $\rightarrow$ syllable syllable syllable

A syllable consists of an onset, a peak and a coda, in that order. A disyllable consists of two syllables, and a trisyllable of three. We can, in turn, use DATR to express these context-free phrase structure rules.

# vars $yll: syl1 syl2 syl3.
Syllable:
    <> == Null
    <phn root> == <phn syl1>
    <phn $yll form>  == "<phn $yll onset>"
                        "<phn $yll peak>"
                        "<phn $yll coda>".
Disyllable:
    <> == Syllable
    <phn root>  == <phn syl2> <phn syl1>.
Trisyllable:
    <> == Syllable
    <phn root>  == <phn syl3> <phn syl2> <phn syl1>.

Strictly speaking, the definition of Syllable given above is a rule schema, rather than a rule, since it makes crucial use of a variable $yll that ranges over attributes (syl1, syl2, ..) that denote syllable positions. Note also that the maximally unspecified path (<>) at the Syllable node is defined by reference to Null which always returns the empty sequence as its value. An <onset>, <peak> or <coda> which is left undefined at lower levels of the hierarchy will, as a consequence, end up as null.

The definitions of di- and trisyllables number the syllables from the right. This is a language-specific aspect of our analysis and reflects the fact that both English and German morphology primarily involve suffixation. Reference to final syllables is thus more frequent than reference to the initial syllables and it is technically convenient to have a constant identifier (syl1 here) for final syllables.

Exercise 6011

Specify what changes or additions to the code given above need to be made in order to allow for four-syllable objects.

Exercise 6012

Augment the code given above so that theorems deriving from it will contain an explicit encoding of the tree structure that is implicit in the way the equations are organized.