<?xml version="1.0" standalone="yes"?>
<Paper uid="P90-1027">
  <Title>AUTOMATED INVERSION OF LOGIC GRAMMARS FOR GENERATION</Title>
  <Section position="9" start_page="218" end_page="218" type="concl">
    <SectionTitle>
CONCLUSIONS
</SectionTitle>
    <Paragraph position="0"> In this paper we presented an algorithm for automated inversion of a unification parser for natural language into an efficient unification generator. The inverted program of the generator is obtained by an off-line compilation process which directly manipulates the PROLOG code of the parser program.</Paragraph>
    <Paragraph position="1"> We distinguish two logical stages of this transformation: computing the minimal sets of essential arguments (MSEA's) for predicates, and generating the inverted program code with INVERSE. The method described here is contrasted with the approaches that seek to define a generalized but computationally expensive evaluation strategy for running a grammar in either direction without manipulating its rules (Shieber, 1988), (Shieber et al., 1989), 0Vedekind, 1989), and see also (Naish, 1986) for some relevant techniques. We have completed a first implementation of the system and used it to derive both a parser and a generator from a single DCG grammar for English. We note that the present version of INVERSE can operate only upon the declarative specification of a logic grammar and is not prepared to deal with extra-logical control operators such as the cut.</Paragraph>
  </Section>
class="xml-element"></Paper>