Model-Theory and Implementation of Property Grammars with Features
Résumé
Property Grammar (PG) is a formalism introduced by Blache (Blache, 2000), which aims at describing syntax in terms of local constraints that can be independently violated. A promising feature of this formalism lies in its ability to account for ungrammatical utterances, thus departing from classical formalisms of generative-enumerative syntax. In this article, we present a model-theoretic description of PG that improves on previous work by providing support for properties augmented with feature constraints. (e.g., the requirement and agreement properties). While providing a formal definition of the semantics of feature-based PG, we illustrate various uses of features within this formalism and give a general framework to interpret them. In a second part, we show how this formalization of PG can be turned into a Constraint Optimization Problem to implement a PG parser that supports the computation of both syntactic trees (for grammatical sentences) and quasi-syntactic trees (i.e., linguistically motivated syntactic structure for ungrammatical utterances). Finally we briefly report on the implementation of such a parser using the Gecode library for Constraint Programming.