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<Paper uid="P89-1003">
  <Title>A THREE-VALUED INTERPRETATION OF NEGATION IN FEATURE STRUCTURE DESCRIPTIONS</Title>
  <Section position="5" start_page="22" end_page="22" type="concl">
    <SectionTitle>
5 Conclusions
</SectionTitle>
    <Paragraph position="0"> A logical formalism with a complete set of logical operators has come to be accepted as a means of describing feature structures. While the intended semantics of most of these operators is well understood, the negation and implication operators have raised some problems, leading to a variety of approaches in their interpretation. In the present work, we have presented an interpretation that combines the following advantages: it is formally simple as well as uniform (it places no special restriction on the negation operator); it is motivated by the linguistic applications of feature structures; it takes into account the partial nature of feature structures by preserving the property of monotonicity under unification and it is computationally no harder than the Rounds-Kasper logic. More significantly, perhaps, we have shown that most existing interpretations of negation can also be expressed within three-valued logic. This framework therefore provides a means for comparing and evaluating various interpretations.</Paragraph>
  </Section>
class="xml-element"></Paper>