<?xml version="1.0"?>
<concept name="LessThanComparable" category="Utility"><!--
Based on concepts from the SGI Standard Template Library documentation:
Copyright (c) 1996-1999
Silicon Graphics Computer Systems, Inc.

Copyright (c) 1994
Hewlett-Packard Company
--><!--
Copyright 2000-2001 University of Notre Dame du Lac.
Copyright 2001-2002 Indiana University.
Some concepts based on versions from the MTL draft manual and Boost Graph
and Property Map documentation:
Copyright (c) Jeremy Siek, Lie-Quan Lee, and Andrew Lumsdaine 2000
-->
  <param name="X" role="comparable-type"/>

  <models-sentence>The type <arg num="1"/> must be a model of <self/>.</models-sentence>

  <description><para>LessThanComparable types must have <code>&lt;</code>,
  <code>&gt;</code>, <code>&lt;=</code>, and <code>&gt;=</code>
  operators.</para></description>

  <notation variables="x y"><sample-value><type name="X"/></sample-value></notation>

  <valid-expression name="Less than">
    <less-than>
      <sample-value><type name="X"/></sample-value>
      <sample-value><type name="X"/></sample-value>
    </less-than>
    <return-type>
      <convertible-to testable="yes">
	<type name="bool"/>
      </convertible-to>
    </return-type>
    <semantics>Determine if one value is less than another.</semantics>
  </valid-expression>

  <valid-expression name="Less than or equal">
    <less-than-or-equal>
      <sample-value><type name="X"/></sample-value>
      <sample-value><type name="X"/></sample-value>
    </less-than-or-equal>
    <return-type>
      <convertible-to testable="yes">
	<type name="bool"/>
      </convertible-to>
    </return-type>
    <semantics>Determine if one value is less than or equal to another.</semantics>
  </valid-expression>

  <valid-expression name="Greater than">
    <greater-than>
      <sample-value><type name="X"/></sample-value>
      <sample-value><type name="X"/></sample-value>
    </greater-than>
    <return-type>
      <convertible-to testable="yes">
	<type name="bool"/>
      </convertible-to>
    </return-type>
    <semantics>Determine if one value is greater than another.</semantics>
  </valid-expression>

  <valid-expression name="Greater than or equal to">
    <greater-than-or-equal>
      <sample-value><type name="X"/></sample-value>
      <sample-value><type name="X"/></sample-value>
    </greater-than-or-equal>
    <return-type>
      <convertible-to testable="yes">
	<type name="bool"/>
      </convertible-to>
    </return-type>
    <semantics>Determine if one value is greater than or equal to another.</semantics>
  </valid-expression>

  <example-model>
    <type name="int"/>
  </example-model>
</concept>
