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<Paper uid="P84-1024">
  <Title>Semantic Interpretation Using KL-ONE 1</Title>
  <Section position="8" start_page="105" end_page="105" type="concl">
    <SectionTitle>
8. Conclusion
</SectionTitle>
    <Paragraph position="0"> We have presented approaches to typical difficulties in building semantic interpreters. These have included a sketch of a translation system that maps from the matched frames to KL-ONE meaning representations. The idea of abstract case frames and applications of them were introduced. Finally, ways of accepting neutral references and allowing for the inter-constituent constraints imposed by relative clauses were presented.</Paragraph>
    <Paragraph position="1"> Our experience indicates that KL-ONE is effective as a means of building and employing a library of case frames. The basic approach is being used in research computer systems at both USC/Information Sciences Institute and Bolt Beranek and Newman, Inc.</Paragraph>
    <Paragraph position="2"> Of course, many problems remain to be solved. Problems currently under investigation include:  - Robust response to input that appears semantically ill.formed, such as using an unknown word, - A general treatment of quantification, - Treatment of.conjunction, . Feedback from the pragmatic component to guide semantic interpretation, * Generation of error messages (in English) based on the case frames if the request seems beyond the system's capabilities, - Understanding classes of metonymy, such as &amp;quot;Send  this window to Jones,&amp;quot; and * Provision for meaningful use of nonsense phrases, such as &amp;quot;Can I send a package over the ARPAnet?&amp;quot; I. Brief Description of KL-ONE KL-ONE offers a rigorous means of specifying terms (concepts) and basic relationships among them, such as subset/superset, disjointness, exhaustive cover, and relational structure. Concepts are denoted graphically as ovals. Concepts are Structured objects whose structure is indicated by named relations (ro/es) between concepts. Roles are drawn as arcs containing a circle and square. The concepts at the end of the role arcs are said to be va/ue restrictions. In addition, roles have maximum and minimum restrictions on the number of concepts that can be related by the role to the concept at the origin of the arc. Concepts can also have data attached to them, stored as a property list. Finally, the set of concepts is organized into an inheritance hierarchy, through subc relations drawn with double. line arrows from the subconcept to the superconcept.</Paragraph>
    <Paragraph position="3"> All of the KL-ONE diagrams in the text are incomplete; for instance, Figures 3 and 5 focus on different aspects of what is one KL-ONE structure. In figure 3, the diagram for SEND-CLAUSE specifies the concepts of &amp;quot;send&amp;quot; clauses. They have exactly one head, which must be the lexical concept &amp;quot;send.&amp;quot; Theymust have a direct object which is a MESSAGE.NP, and they optionally have an indirect object which is a USER-NP. Figure 5 shows that SEND-CLAUSE's are MESSAGE-TRANSMISSION-CLAUSE's, which are a type of CLAUSE. The meaning representation, Figure 2, generated for &amp;quot;Send him the message that arrived yesterday&amp;quot; consists of the concept Send-mail, having an addressee which is a Computer-User and a message which is ComputerMail.</Paragraph>
  </Section>
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