Valence Alternation without Lexical Rules

Valence changing lexical rules are a problematic component of constraint-based grammar formalisms. Lexical rules of this type are procedural, require defaults, and may easily lead to spurious ambiguity. Relational constraints can be used to eliminate such rules. The relational approach does not require defaults, is declarative, avoids spurious ambiguity, and can be an integrated part of a hierarchically structured lexicon. This is illustrated below for the complement extraction and adjunct introduction lexical rules of hpsg. We argue that, apart from the technical beneets mentioned above, the relational approach is linguistically superior, in that it ooers a uniform account of complement and adjunct extraction. Furthermore, it eliminates the spurious ambiguity that may arise in grammars which include complement inheritance verbs as well as a lexicalist account of complement extraction.