A Declarative Grammar Formalism For Dependency Grammar
Author: Ralph Debusmann
Editor:
Beginning with the groundbreaking work of Chomsky in the 1950s,
syntactians have concentrated mostly on the English language. But
English is not a typical natural language: in particular, its word
order is very rigid, as opposed to most other languages which exhibit
freer word order. The phrase structure-based approach employed for the
analysis of English runs into severe problems when confronted with
freer word order languages.
Aside from the mainstream, linguists in Eastern Europe and Japan have
pursued an approach to syntax which seemed better suited for the
analysis of freer word order languages: dependency grammar. The key
asset of dependency grammar is that it allows for a clean separation
of syntactic dependency and surface word order. Unfortunately, none of
the frameworks for dependency grammar has really caught on. We suggest
two reasons for their failure: a) many of the dependency-based
frameworks lack proper formalization and, perhaps surprisingly, b)
most of them lack a realistic and workable account of word order.
In this thesis, we try to remedy these problems in the setting of a
constraint-based approach to dependency grammar based on
\citeDuchier99. We present a new account of word order for
dependency grammar couched in a declarative grammatical formalism
called Topological Dependency Grammar (TDG). TDG allows to cleanly
separate the two levels of syntactic dependency and surface word
order, which greatly facilitates the conception of grammars for freer
word order languages. In addition, we can efficiently parse with TDG
grammars: using a reduction described in \citeDuchier00, we achieved
an efficient parser implementation using modern constraint programming
techniques.
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