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<Paper uid="P89-1033">
  <Title>PARSING AS NATURAL DEDUCTION</Title>
  <Section position="1" start_page="0" end_page="0" type="abstr">
    <SectionTitle>
Abstract
</SectionTitle>
    <Paragraph position="0"> The logic behind parsers for categorial grammars can be formalized in several different ways. Lambek Calculus (LC) constitutes an example for a natural deduction 1 style parsing method.</Paragraph>
    <Paragraph position="1"> In natural language processing, the task of a parser usually consists in finding derivations for all different readings of a sentence. The original Lambek Calculus, when it is used as a parser/theorem prover, has the undesirable property of allowing for the derivation of more than one proof for a reading of a sentence, in the general case.</Paragraph>
    <Paragraph position="2"> In order to overcome this inconvenience and to turn Lambek Calculus into a reasonable parsing method, we show the existence of &amp;quot;relative&amp;quot; normal form proof trees and make use of their properties to constrain the proof procedure in the desired way.</Paragraph>
  </Section>
class="xml-element"></Paper>