clicliclic@freenet.de wrote:   
   >   
   > Grrrmbl.   
   >   
   > A state-of-the-art implementation of a Risch integrator   
   >   
   > )version   
   >   
   > Value = "FriCAS 1.3.0 compiled at Thu Sep  1 17:01:37 UTC 2016"   
   >   
   > responds to   
   >   
   > integrate((1 + x)/((1 + x + x^2)*(a + b*x^3)^(1/3)), x)   
   >   
   > with   
   >   
   > >> Error detected within library code:   
   >    catdef: division by zero   
   >   
   > In his "Symbolic Integration Tutorial", Bronstein appears to believe in   
   > the existence of a workable integration algorithm for algebraic   
   > integrands involving a simple radical extension. Didn't he know what he   
   > was talking about?   
      
   Writing paper he ceratainly knew what is is writing.  But writing   
   code he apparently assumed that he will be lucky.  Or to put it   
   differetly: code he wrote is enough to "demostrate" that algorithm   
   works.  But there remain "uninteresting" programming probles to   
   resolve.  To the point: his code uses random integers.  If   
   substituting those integers into one of denominators gives zero,   
   then you will see this error.  Correct algorithm would retry   
   with different values.  But his code just gives error.  Recent   
   changes to FriCAS lead to change in random choice and for   
   some integrals (like this one) the problem became very visible.   
      
   One can try to hide the problem using more randomness.  Or   
   one can do "uninteresting" programming and properly implement   
   retry.   
      
   BTW: This is FriCAS bug and proper place to report this is   
   FriCAS mailing list or Sourceforge bugtracke.  And this   
   problem was was already reported (after relase of 1.3.0).   
      
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