clicliclic@freenet.de wrote:   
   >   
   > Axel Vogt schrieb:   
   > >   
   > > On 14.03.2017 08:13, clicliclic@freenet.de wrote:   
   > > >   
   > > > antispam@math.uni.wroc.pl schrieb:   
   > > >>   
   > > >> After 10 hours FriCAS returns unevaluated integral.   
   > > >>   
   > > >   
   > > > Thanks, I can accept this result easily. I was just trying to find out   
   > > > on the quick (!) if the integral is elementary - and instead (after a   
   > > > quite acceptable minute or so) obtained what looked like the   
   > > > manifestation of a bug.   
   > > >   
   > > > The result for the second version of the integral implies that the first   
   > > > version:   
   > > >   
   > > >   integrate(1/((p*sqrt(1 - x^2) - 1)*sqrt(p*sqrt(1 - x^2) - x^2)), x)   
   > > >   
   > > > should be returned unevaluated as well. I see that the FriCAS version of   
   > > > the web interface has been updated to 1.3.1, but the "Denominator not   
   > > > equal to 1" error remains.   
   > > >   
   > >   
   > > For (the real case) I used x = sin(z) and -Pi/2 < z < Pi/2 (to avoid   
   > > troubles for sqrt( cos(z) ) and got a lengthy answer in terms of   
   > > elliptic functions and nested roots, using Maple, in some seconds.   
   > >   
   > > I did no cross check (and do not trust results of such type here)   
   > >   
   >   
   > Putting x = SIN(z) does not help with FriCAS: For either of the two   
   > trigonometric equivalents:   
   >   
   > \begin{axiom}   
   > setSimplifyDenomsFlag(true)   
   > integrate(cos(z)/((p*cos(z) - 1)*sqrt(p*cos(z) - sin(z)^2)), z)   
   > \end{axiom}   
   >   
   > and:   
   >   
   > \begin{axiom}   
   > setSimplifyDenomsFlag(true)   
   > integrate(cos(z)/((cos(z) - q)*sqrt(cos(z) - q*sin(z)^2)), z)   
   > \end{axiom}   
   >   
   > of the algebraic integral, the FriCAS web interface returns:   
   >   
   > >> Error detected within library code:   
   >    Imaginary part is nonzero. Cannot retract.   
   >   
   > The web interface is now using version 1.3.1 of FriCAS.   
      
   This problem is fixed in trunk (problem was known for longer   
   time, but fix was not ready for release).  There is some   
   weirdness here, today in fresh session both returned unevaluated   
   in less than a second, but after interrupted trial without   
   'setSimplifyDenomsFlag(true)' take a lot of time...   
      
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