Lexical Constraint Grammars

Closing the Gap Between Stochastic and Rule-based LFG Grammars

Developing large-scale deep grammars in a constraint-based framework such as Lexical Functional Grammar (LFG) is time-consuming and requires significant linguistic insight. Recently, treebank-based constraint-grammar acquisition approaches have been developed as an alternative to hand-crafting such resources. While treebank-based approaches are wide coverage and robust and achieve competitive e...

Lexical Rules In Constraint-Based Grammars

Lexical rules have been used to cover a very diverse range of phenomena in constraint-based grammars. Examination of the full range of rules proposed shows that Carpenter’s (1991) postulated upper bound on the length of list-valued attributes such as subcat in the lexicon cannot be maintained, leading to unrestricted generative capacity in constraint-based formalisms utilizing HPSG-style lexica...

Towards Uniform Processing Of Constraint-Based Categorial Grammars

A class of constraint-based categorial grammars is proposed in which the construction of both logical forms and strings is specified completely lexically. Such grammars allow the construction of a uniform algorithm for both parsing and generation. Termination of the algorithm can be guaranteed if lexical entries adhere to a constraint, that can be seen as a computationally motivated version of ...

Optimality Theory Style Constraint Ranking in Large-scale LFG Grammars

Treebank-Based Acquisition of a Chinese Lexical-Functional Grammar

Scaling wide-coverage, constraint-based grammars such as Lexical-Functional Grammars (LFG) (Kaplan and Bresnan, 1982; Bresnan, 2001) or Head-Driven Phrase Structure Grammars (HPSG) (Pollard and Sag, 1994) from fragments to naturally occurring unrestricted text is knowledge-intensive, time-consuming and (often prohibitively) expensive. A number of researchers have recently presented methods to a...