Eckhard Bick - VISL

7.2.5. Syntactic tree structures
While the "enriched text" notation (cp. illustration (3) in chapter 7.1.) is ideal for
combining the natural flow of running text with word class and function information
in a graphical way, it does not emphasise constituent structure. Rather, the latter is
expressed indirectly, and in a flat way, by mounting heads and dependents into
constituents with the help of directed "dependency markers". Adnominals, for
instance, are mounted on “N-words” (i.e., typically, nouns): @>N points to an nphead
to the right, thus signalling a prenominal modifier, while @N< stands for a
postnominal modifier (attaching left). Still, the dependency grammar embodied by
the system's Portuguese Constraint Grammar rules is detailed and precise enough to
permit automatic transformation into PSG-like tree structures (chapter 4.6.3). This is
achieved by running a perl-compiled set of substitution rules on top of a detailed CG
analysis 237 , mapping constituent borders and deriving complex constituent function
from function tags at the dependency heads in question.
(3) Automatic transformation into syntactic tree structures
237 In the English VISL-system, I have written an ordinary generative grammar running on top of a CG-system enhanced
with rules for subclause form and function. The - declarative - generative system is better at capturing tree structure
ambiguity, but faces more serious time & space problems than the - procedural - substitution rule program.