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<A NAME=SUB>

<TITLE>SUB</TITLE></A>
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<B>SUB</B> _ _ _  _ _ _  _ _ _  _ _ _ <B>operator</B><P>
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The <em>sub</em> operator substitutes a new expression for a kernel in an 
expression. 
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syntax: </H3>
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<em>sub</em>(&lt;kernel&gt;<em>=</em>&lt;expression&gt; 
	 {,&lt;kernel&gt;<em>=</em>&lt;expression&gt;}*, 
	 &lt;expression&gt;) or 
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<em>sub</em>({&lt;kernel&gt;<em>=</em>&lt;expression&gt;*, 
	 &lt;kernel&gt;<em>=</em><em>expression</em>},&lt;expression&gt;) 
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&lt;kernel&gt; must be a 
<A HREF=r37_0002.html>kernel</A>, &lt;expression&gt; can be any REDUCE 
scalar expression. 
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examples: </H3>
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sub(x=3,y=4,(x+y)**3); 

  343 


x; 

  X 


sub({cos=sin,sin=cos},cos a+sin b) 


  COS(B) + SIN(A)

</TT></PRE><P>Note in the second example that operators can be replaced using th
e 
<em>sub</em> operator. 
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