Modularity of grammatical constraints in HPSG-based grammar implementations

This paper is a contribution to the discussion of the choices involved in implementing HPSG-based grammars and their consequences on the modularity and reusability of grammatical resources, a central issue in multi-lingual grammar development. Based on two examples from the English Resource Grammar (Flickinger et al., 2000), the treatment of unbounded dependencies and the analysis of optional arguments, we show that adding recursive relations to the expressive means available to the grammar writer results in more modular, transparent, and compact grammars. Given the frequent use of recursive relations in HPSG linguistics, grammar implementations integrating such relations can also be closer to the linguistic generalizations they intend to implement.