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<A NAME=NUMBERP>

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



<B>NUMBERP</B> _ _ _  _ _ _  _ _ _  _ _ _ <B>operator</B><P>
<P>
 
The <em>numberp</em> operator returns 
<A HREF=r37_0122.html>true</A> if its argument is a number, 
and 
<A HREF=r37_0014.html>nil</A> otherwise. 
 <P> <H3> 
syntax: </H3>
<P>
<P>
<em>numberp</em>(&lt;expression&gt;) or <em>numberp</em> &lt;expression&gt; 
<P>
<P>
<P>
&lt;expression&gt; can be any REDUCE scalar expression. 
<P>
<P>
 <P> <H3> 
examples: </H3>
<P><PRE><TT>
cc := 15.3; 

  CC := 15.3 


if numberp(cc) then write &quot;number&quot; else write &quot;nonnumber&quot;; 


  number 


if numberp(cb) then write &quot;number&quot; else write &quot;nonnumber&quot;; 


  nonnumber

</TT></PRE><P>Logical operators can only be used in conditional expressions, suc
h as 
<P>
<P>
<em>if</em>...<em>then</em>...<em>else</em> and <em>while</em>...<em>do</em>. 
<P>
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<P>