(13) Language Analysis Tools based on Unification-based Grammar

The system provides an integrated environment for parsing natural language texts as well as for observing the trace of the parsing process. The system consists of the following components: 1) a Chart-based parsing system, called SAX, that runs with a Definite Clause Grammar by compiling the given grammar (in this project, an HPSG has been developed) into a fast Prolog code, 2) a statistical dependency analysis system that works for reduction of syntactic ambiguity, and 3) a user interface to show the intermediate parsing process. In the statistical dependency analyzer, The statistics of the modifier-modifiee dependencies between phrases are acquired from a parsed corpus and is used in the later analysis so as to avoid constructing phrases with low probability. Improvement of the system is automatically achieved by accumulating correct parsed corpus.