Ambiguity packing in constraint-based parsing - practical results

We describe a novel approach to 'packing' of local ambiguity in parsing with a wide-coverage HPSG grammar, and provide an empirical assessment of the interaction between various packing and parsing strategies. We present a linear-time, bidirectional subsumption test for typed feature structures and demonstrate that (a) subsumption- and equivalence-based packing is applicable to large HPSG grammars and (b) average parse complexity can be greatly reduced in bottom-up chart parsing with comprehensive HPSG implementations.