In developing the OVIS2 grammar we have tried to combine the short-term goal of developing a grammar which meets the requirements imposed by the application (i.e. robust processing of the output of the speech recogniser, extensive coverage of locative phrases and temporal expressions, and the construction of fine-grained semantic representations) with the long-term goal of developing a general, computational, grammar which covers all the major constructions of Dutch.
The design and organisation of the grammar, as well as many aspects of the particular grammatical analyses we propose, are based on Head-driven Phrase Structure Grammar [36]. We depart from this formalism mostly for computational reasons. As is explained below, the grammar is compiled into a restricted kind of definite clause grammar for which efficient processing is feasible. The semantic component follows the approach to monotonic semantic interpretation using quasi-logical forms presented originally in Alshawi [3].
The grammar currently covers the majority of verbal subcategorisation types (intransitives, transitives, verbs selecting a PP, and modal and auxiliary verbs), NP-syntax (including pre- and post-nominal modification, with the exception of relative clauses), PP-syntax, the distribution of VP-modifiers, various clausal types (declaratives, yes/no and WH-questions, and subordinate clauses), all temporal expressions and locative phrases relevant to the domain, and various typical spoken-language constructs. Due to restrictions imposed by the speech recogniser, the lexicon is relatively small (3200 word forms, many of which are names of stations and cities).
In sections 2.1- 2.3 we introduce the grammar formalism from both a computational and linguistic perspective. Section 2.4 describes the grammar of noun, prepositional, and verb phrases, subordinate and main clauses, WH-questions and topicalisation, and a number of domain specific constructions. Sections 2.5 and 2.6, finally, are concerned with semantics and the translation of quasi-logical forms into (application-specific) update-expressions.