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<Paper uid="P85-1017">
  <Title>A Structure-Sharing Representation for Unification-Based Grammar Formalisms</Title>
  <Section position="2" start_page="0" end_page="0" type="abstr">
    <SectionTitle>
Abstract
</SectionTitle>
    <Paragraph position="0"> This paper describes a structure-sharing method for the representation of complex phrase types in a parser for PATR-\[I, a unification-based grammar formalism.</Paragraph>
    <Paragraph position="1"> In parsers for unification-based grammar formalisms, complex phrase types are derived by incremental refinement of rite phrase types defined in grammar rules and lexical entries. In a naive implementation, a new phrase type is built by copying older ones and then combining the copies according to the constraints stated in a grammar rule. The structure-sharing method was designed to eliminate most such copying; indeed, practical tests suggest that the use of this technique reduces parsing time by as much as 60%.</Paragraph>
    <Paragraph position="2"> The present work is inspired by the structure-sharing method for theorem proving introduced by Boyer and Moore and on the variant of it that is used in some Prolog implementations. null</Paragraph>
  </Section>
class="xml-element"></Paper>