
<A NAME=REVERSE>

<TITLE>REVERSE</TITLE></A>
<b><a href=r37_idx.html>INDEX</a></b><p><p>



<B>REVERSE</B> _ _ _  _ _ _  _ _ _  _ _ _ <B>operator</B><P>
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The <em>reverse</em> operator returns a 
<A HREF=r37_0053.html>list</A> that is the reverse of the 
list it is given. 
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syntax: </H3>
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<em>reverse</em>(&lt;list&gt;) or <em>reverse</em> &lt;list&gt; 
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&lt;list&gt; must be a 
<A HREF=r37_0053.html>list</A>. 
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examples: </H3>
<P><PRE><TT>
aa := {c,b,a,{x**2,z**3},y}; 

                 2  3
  AA := {C,B,A,{X ,Z },Y} 


reverse aa; 

       2  3
  {Y,{X ,Z },A,B,C} 


reverse(q . reverse aa); 

           2  3
  {C,B,A,{X ,Z },Y,Q}

</TT></PRE><P><em>reverse</em>and 
<A HREF=r37_0043.html>cons</A> can be used together to add a new element to 
the end of a list (<em>.</em> adds its new element to the beginning). The 
<em>reverse</em> operator uses a noticeable amount of system resources, 
especially if the list is long. If you are doing much heavy-duty list 
manipulation, you should probably design your algorithms to avoid much 
reversing of lists. A moderate amount of list reversing is no problem. 
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