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<Paper uid="P83-1004">
  <Title>Formal Constraints on Metarules*</Title>
  <Section position="5" start_page="25" end_page="25" type="concl">
    <SectionTitle>
5. Conclusion
</SectionTitle>
    <Paragraph position="0"> The formal power of metaxule formalisms is clearly an important consideration for computational linguists. Uszkoreit and Pet.era \[1982\] have shown that the potential exists for defining metarule formalisms that are computationally &amp;quot;unsafe.&amp;quot; However, these results do not sound a death knell for metarules.</Paragraph>
    <Paragraph position="1"> On the contrary, the safety of metarule formalisms is still an open question. We have merely shown that the constraints on metarules necessary to make them formally tractable will have to be based on empirical linguiaic evidence as well as solid formal research. The solutions to constraining metarules analyzed here seem to be either formally or linguistically inadequate. Further research is needed in the actual uses of metarules and in constructions that axe problematic for metarules so ~ to develop either linguistically motivated and computationally interesting constraints on the formalisms, or alternative formalisms that axe linguistically adequate but not heir to the problems of metaxules.</Paragraph>
  </Section>
class="xml-element"></Paper>