From: Albert_Rich@msn.com   
      
   On Tuesday, November 4, 2014 7:09:21 AM UTC-10, clicl...@freenet.de wrote:   
      
   > You say that the Rubi 4.6 antiderivative for log(2+x)^3*log(3+x)*x^3   
   > contains six polylogarithm functions. The Mathematica result quoted on   
   > the web page referenced in the original post to this thread contains   
   > just three of them. This could be considered an advantage since you say   
   > that the size of the result is similar.   
      
   Rubi does not automatically apply the Simplify function after integrating.  If   
   Rubi result is simplified the 3 pairs of identical polylogarithm functions are   
   respectively collected, resulting in just 3 polylogarithms just like   
   Mathematica's    
   antiderivative.  Interestingly the two antiderivatives differ by the constant   
   -144205/432.   
      
   Simplification often results in collection over a common denominator. Thus in   
   addition to the time required, automatically simplifying Rubi's results would   
   destroy the terms of the antiderivative each of which is usually the elegant   
   result of a single    
   integration step.  Also it is often the case that each of these terms is no   
   more complicated than the original integrand; thereby making it possible for   
   Rubi to integrate an expression multiple times.   
      
   Albert   
      
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