Abstract

Constraint Dependency Grammar (CDG) is a constraint-based grammatical formalism which has a weak generative capacity beyond context-free grammars and supports a very flexible parsing algorithm for working with feature grammars; however, the running time of the parser is O(n 4 ). Hence, we have investigated how to improve the running time of the parser by applying feature constraints differentially and by using aggregate unary constraints, which can be applied in O(n 2 ) time. Additional speedup was achieved by integrating the filtering algorithm more tightly with the parser and by supporting the use of a varying number of roles for word classes. Key words: Parsing, NLP, Constraint Satisfaction. Introduction: CDG Parsing Constraint Dependency Grammar, introduced by Maruyama [1, 2, 3], uses constraints to determine which dependencies are grammatical for a sentence. The parsing algorithm is framed as a constraint satisfaction problem: the parsing rules are the constraints and the s...

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