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<A NAME=PROD>

<TITLE>PROD</TITLE></A>
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<B>PROD</B> _ _ _  _ _ _  _ _ _  _ _ _ <B>operator</B><P>
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The operator <em>prod</em> returns 
the indefinite or definite product of a given expression. 
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syntax: </H3>
<em>prod</em>(&lt;expr&gt;,&lt;k&gt;[,&lt;lolim&gt; [,&lt;uplim&gt; ]]) 
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where &lt;expr&gt; is the expression to be multiplied, &lt;k&gt; is the 
control variable (a 
<A HREF=r37_0002.html>kernel</A>), and &lt;lolim&gt; and &lt;uplim&gt; 
uplim are the optional lower and upper limits. If &lt;uplim&gt; is 
not supplied the upper limit is taken as &lt;k&gt;. The 
Gosper algorithm is used. If there is no closed form solution, 
the operator returns the input unchanged. 
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examples: </H3>
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prod(k/(k-2),k);

  k*( - k + 1)

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