1Lexicalization of Context

1.1 Introduction This paper proposes the lexicalization of context in HPSG. Instead of phrasal amalgamation of contextual information from a phrase's daughters , which is speciied by the Principle of Contextual Consistency of Pollard and Sag 1994, we propose lexical amalgamation of context from a word's arguments by means of lexical constraints. The Principle of Contextual Consistency is replaced by a Contextual Head Inheritance Principle, in which a phrase's CONTEXT feature is token-identical to that of its contextual head daughter. We ooer motivations for the proposal on theoretical, computational 1 and linguistic levels. The paper has three main parts. Section 1.2 shows that the proposal naturally follows other recent revisions in HPSG theory concerned with set-valued features, and brings the handling of context features into line on a theoretical level with the lexicalization of nonlocal features and of quantiier storage. Section 1.3 argues that the lexicalization of context, combined with the lexicalization of quantiier scoping, allows the idea of semantic heads to regain its original signiicance, which otherwise is lost when quantiier retrieval and background conditions are involved. Section 1.4 brieey sketches a linguistic analysis which combines the lex-icalization of context with the lexicalization of nonlocal features, in an approach to register variation within Sag's analysis of English relative clauses. 1 A version of this paper was presented at the 4th International Conference on HPSG at Ithaca, NY in July 1997. The material included there on head-driven generation, which forms the main motivation on a computational level, has been transferred to another paper (Wilcock and Matsumoto to appear) which describes a computational implementation of the ideas presented here. We start by comparing two alternative approaches to the amalgamation of set-valued features: the phrasal approach of Pollard and Sag 1994 and the lexical approach of more recent proposals. Three principles-the Nonlocal Feature Principle, the Quantiier Inheritance Principle, and the Principle of Contextual Consistency-specify constraints on certain set-valued features of a phrase and the equivalent set-valued features of the daughters. In Pollard and Sag 1994, these constraints are speciied on phrases, that is, the values of the relevant features of all the daughters of a phrase are amalgamated by set union (possibly with subtraction of certain elements) to give the value of the relevant feature of the phrase. We therefore refer to this phrase-based amalgamation of set-valued features as phrasal amalgamation. The Nonlocal Feature Principle requires each of the INHERITED features QUE, …