File r37/lisp/csl/html/r37_0078.html artifact 3c9e3abea9 part of check-in 1b32ca91d4

<A NAME=DILOG>

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



<B>DILOG</B> _ _ _  _ _ _  _ _ _  _ _ _ <B>operator</B><P>
<P>
 
 <P>
<P>
The <em>dilog</em> operator is known to the differentiation and integration 
operators, but has numeric value attached only at <em>dilog(0)</em>. Dilog is 
defined by 
<P>
<P>
dilog(x) = -int(log(x),x)/(x-1) 
<P>
<P>
 <P> <H3> 
examples: </H3>
<P><PRE><TT>
df(dilog(x**2),x); 

           2
    2*LOG(X )*X
  - ------------
       2
      X   - 1



int(dilog(x),x); 

  DILOG(X)*X - DILOG(X) + LOG(X)*X - X 



dilog(0); 

    2
  PI
  ----
   6

</TT></PRE><P>