
<A NAME=DILOG_extended>

<TITLE>DILOG_extended</TITLE></A>
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<B>DILOG EXTENDED</B> _ _ _  _ _ _  _ _ _  _ _ _ <B>operator</B><P>
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The package <em>specfn</em> supplies an extended support for the 

<A HREF=r37_0078.html>dilog</A> operator which implements the <em>dilogarithm fu
nction</em>. 
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dilog(x) := - defint(log(t)/(t - 1),t,1,x); 
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 <P> <H3> 
syntax: </H3>
<em>Dilog</em>(&lt;order&gt;,&lt;expression&gt;) 
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examples: </H3>
<P><PRE><TT>
defint(log(t)/(t - 1),t,1,x); 

  - dilog (x) 


dilog 2; 

      2
  - pi  /12 



on rounded; 

Dilog 20; 

  - 5.92783972438

</TT></PRE><P>The operator <em>Dilog</em> is sometimes called Spence's Integral 
for n = 2. 
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