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<head><title>HINTS.html -- ACL2 Version 3.0.1</title></head>
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<head><title>HINTS.html -- ACL2 Version 3.1</title></head>
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<h2>HINTS</h2>advice to the theorem proving process
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<pre>Major Section: <a href="MISCELLANEOUS.html">MISCELLANEOUS</a>
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<code>:INDUCT</code><br>
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<code>Value</code> is either <code>t</code> or a term containing at least one recursively
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defined function symbol; if <code>t</code>, this hint indicates that the system
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should proceed to apply its induction heuristic to the specified
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goal produced (without trying simplification, etc.); if <code>value</code> is
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a term other than <code>t</code>, then not only should the system apply
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induction immediately, but it should analyze <code>value</code> rather than
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the goal to generate its <a href="INDUCTION.html">induction</a> scheme. Merging and the
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other <a href="INDUCTION.html">induction</a> heuristics are applied. Thus, if <code>value</code>
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contains several mergeable <a href="INDUCTION.html">induction</a>s, the ``best'' will be
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defined function symbol. If <code>t</code>, this hint indicates that the system
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should proceed to apply its <a href="INDUCTION.html">induction</a> heuristic to the specified goal
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(without trying simplification, etc.). If <code>value</code> is of the form
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<code>(f x1 ... xk)</code>, where <code>f</code> is a recursively defined function and <code>x1</code>
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through <code>xk</code> are distinct variables, then the system is to induct according
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to the <a href="INDUCTION.html">induction</a> scheme that was stored for <code>f</code>. For example, for the
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hint <code>:induct (true-listp x)</code>, ACL2 will assume that the goal holds for
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<code>(cdr x)</code> when proving the induction step because <code><a href="TRUE-LISTP.html">true-listp</a></code> recurs
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on the <code><a href="CDR.html">cdr</a></code>. More generally, if <code>value</code> is a term other than <code>t</code>,
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then not only should the system apply induction immediately, but it should
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analyze <code>value</code> rather than the goal to generate its <a href="INDUCTION.html">induction</a> scheme.
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Merging and the other <a href="INDUCTION.html">induction</a> heuristics are applied. Thus, if
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<code>value</code> contains several mergeable <a href="INDUCTION.html">induction</a>s, the ``best'' will be
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created and chosen. E.g., the <code>:induct</code> hint