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<Paper uid="P95-1003">
  <Title>The Replace Operator</Title>
  <Section position="4" start_page="22" end_page="22" type="concl">
    <SectionTitle>
4. Conclusion
</SectionTitle>
    <Paragraph position="0"> The goal of this paper has been to introduce to the calculus of regular expressions a replace operator, -&gt;, with a set of associated replacement expressions that concisely encode alternate variations of the operation.</Paragraph>
    <Paragraph position="1"> We defined unconditional and conditional replacement, taking the unconditional obligatory replacement as the basic case. We provide a simple declarative definition for it, easily expressed in terms of the other regular expression operators, and extend it to the conditional case providing four ways to constrain replacement by a context.</Paragraph>
    <Paragraph position="2"> These definitions have already been implemented.</Paragraph>
    <Paragraph position="3"> The figures in this paper correspond exactly to the output of the regular expression compiler in the Xerox finite-state calculus.</Paragraph>
  </Section>
class="xml-element"></Paper>