Generalizing Dimensionality in Combinatory Categorial Grammar

Abstract

We extend Combinatory Categorial Grammar (CCG) with a generalized notion of multidimensional sign, inspired by the types of representations found in constraint-based frameworks like HPSG or LFG. The generalized sign allows multiple levels to share information, but only in a resource-bounded way through a very restricted indexation mechanism. This improves representational perspicuity without increasing parsing complexity, in contrast to full-blown unification used in HPSG and LFG. Well-formedness of a linguistic expressions remains entirely determined by the CCG derivation. We show how the multidimensionality and perspicuity of the generalized signs lead to a simplification of previous CCG accounts of how word order and prosody can realize information structure.