  We describe an approach to robust domain-independent syntactic parsing of
unrestricted naturally-occurring (English) input. The technique involves
parsing sequences of part-of-speech and punctuation labels using a
unification-based grammar coupled with a probabilistic LR parser. We describe
the coverage of several corpora using this grammar and report the results of a
parsing experiment using probabilities derived from bracketed training data. We
report the first substantial experiments to assess the contribution of
punctuation to deriving an accurate syntactic analysis, by parsing identical
texts both with and without naturally-occurring punctuation marks.
