Syntactic-Head-Driven Generation

The previously proposed s e m a n l i c h e a d d r i w ' . n Ken eration methods run into problems if none of the daughter eonst i tuents in the syntact.o-semantic rule schemata of a g rammar fits the definition of a semantic head given in [Shieber et al., 1990]. This is the case for the semantic analysis rnles of certain constraintbased semant ic representations, e.g. Underspecified Discourse R,epresentation Structures (UI)RSs) [l!'rank and R.eyle, 1992]. Since head-driven generation in general has its me> its, we simply return to a syntactic definition of qmad' and demonst ra te the feasibility of s y n l a c l i c head-clriveu generation. In addit ion to its generality, a syntact ic-head-driven algori thm provides a basis for a logically well-defined t rea tment of the nmvement of (syntactic) heads, for which only ad-hoc solutions existed, so far.