Performance Grammar: a Declarative De nition

In this paper we present a deŽ nition of PerformanceGrammar (PG), a psycholinguistically motivated syntax formalism, in declarative terms. PG aims not only at describing and explaining intuitive judgments and other data concerning the well–formedness of sentences of a language, but also at contributing to accounts of syntactic processing phenomena observable in language comprehension and language production. We highlight two general properties of human sentence generation, incrementalityand late linearization,which make special demands on the design of grammar formalisms claiming psychological plausibility. In order to meet these demands, PG generates syntactic structures in a two-stage process. In the Ž rst and most important ‘hierarchical’ stage, unordered hierarchical structures (‘mobiles’) are assembled out of lexical building blocks. The key operation at work here is typed feature uniŽ cation, which also delimits the positional options of the syntactic constituents in terms of so-called topological features. The second, much simpler stage takes care of arranging the branches of the mobile from left to right by ‘reading–out’ one positional option of every constituent. In this paper we concentrate on the structure assembly formalism in PG’s hierarchical component. We provide a declarative deŽ nition couched in an HPSG–style notation based on typed feature uniŽ cation. Our emphasis throughout is on linear order constraints.