In this paper, we report on a transformation scheme that turns a Categorial
Grammar, more specifically, a Combinatory Categorial Grammar (CCG; see
Baldridge, 2002) into a derivation- and meaning-preserving typed feature
structure (TFS) grammar.
We describe the main idea which can be traced back at least to work by
Karttunen (1986), Uszkoreit (1986), Bouma (1988), and Calder et al. (1988).
We then show how a typed representation of complex categories can be extended
by other constraints, such as modes, and indicate how the Lambda semantics of
combinators is mapped into a TFS representation, using unification to perform
perform alpha-conversion and beta-reduction (Barendregt, 1984).
We also present first findings concerning runtime measurements, showing
that the PET system, originally developed for the HPSG grammar framework,
outperforms the OpenCCG parser by a factor of 8–10 in the time domain and a
factor of 4–5 in the space domain.
Maintained by Stefan Müller
Created: November 11, 2011
Last modified: January 09, 2019