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  67. <a name="Comparison-functions-for-poly_005fint-1"></a>
  68. <h4 class="subsection">10.3.1 Comparison functions for <code>poly_int</code></h4>
  69. <p><code>poly_int</code> provides the following routines for checking whether
  70. a particular condition &ldquo;may be&rdquo; (might be) true:
  71. </p>
  72. <div class="example">
  73. <pre class="example">maybe_lt maybe_le maybe_eq maybe_ge maybe_gt
  74. maybe_ne
  75. </pre></div>
  76. <p>The functions have their natural meaning:
  77. </p>
  78. <dl compact="compact">
  79. <dt>&lsquo;<samp>maybe_lt(<var>a</var>, <var>b</var>)</samp>&rsquo;</dt>
  80. <dd><p>Return true if <var>a</var> might be less than <var>b</var>.
  81. </p>
  82. </dd>
  83. <dt>&lsquo;<samp>maybe_le(<var>a</var>, <var>b</var>)</samp>&rsquo;</dt>
  84. <dd><p>Return true if <var>a</var> might be less than or equal to <var>b</var>.
  85. </p>
  86. </dd>
  87. <dt>&lsquo;<samp>maybe_eq(<var>a</var>, <var>b</var>)</samp>&rsquo;</dt>
  88. <dd><p>Return true if <var>a</var> might be equal to <var>b</var>.
  89. </p>
  90. </dd>
  91. <dt>&lsquo;<samp>maybe_ne(<var>a</var>, <var>b</var>)</samp>&rsquo;</dt>
  92. <dd><p>Return true if <var>a</var> might not be equal to <var>b</var>.
  93. </p>
  94. </dd>
  95. <dt>&lsquo;<samp>maybe_ge(<var>a</var>, <var>b</var>)</samp>&rsquo;</dt>
  96. <dd><p>Return true if <var>a</var> might be greater than or equal to <var>b</var>.
  97. </p>
  98. </dd>
  99. <dt>&lsquo;<samp>maybe_gt(<var>a</var>, <var>b</var>)</samp>&rsquo;</dt>
  100. <dd><p>Return true if <var>a</var> might be greater than <var>b</var>.
  101. </p></dd>
  102. </dl>
  103. <p>For readability, <code>poly_int</code> also provides &ldquo;known&rdquo; inverses of these
  104. functions:
  105. </p>
  106. <div class="example">
  107. <pre class="example">known_lt (<var>a</var>, <var>b</var>) == !maybe_ge (<var>a</var>, <var>b</var>)
  108. known_le (<var>a</var>, <var>b</var>) == !maybe_gt (<var>a</var>, <var>b</var>)
  109. known_eq (<var>a</var>, <var>b</var>) == !maybe_ne (<var>a</var>, <var>b</var>)
  110. known_ge (<var>a</var>, <var>b</var>) == !maybe_lt (<var>a</var>, <var>b</var>)
  111. known_gt (<var>a</var>, <var>b</var>) == !maybe_le (<var>a</var>, <var>b</var>)
  112. known_ne (<var>a</var>, <var>b</var>) == !maybe_eq (<var>a</var>, <var>b</var>)
  113. </pre></div>
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