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|    sci.math.symbolic    |    Symbolic algebra discussion    |    10,432 messages    |
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|    Message 9,952 of 10,432    |
|    nma%12000.org@gtempaccount.com to clicl...@freenet.de    |
|    Re: collected FriCAS failures (the remai    |
|    14 Feb 19 02:26:51    |
      I went over some of these using latest Fricas 1.3.5.1 on Linux Manjaro              On Thursday, October 18, 2018 at 5:24:40 AM UTC-5, clicl...@freenet.de wrote:       > This list of 12 noteworthy FriCAS failures collected from my       > integration files supersedes its predecessor containing 14 integrals.       > A new pseudo-elliptic integrand involving dependent nested roots of       > integers has been added at the end:       >       .....       >       > - no closed form for Timofeev 5.66 (#401):       > result of integrate(tan(x)/(sqrt(tan(x)) - 1)^2, x) is correct but       > involves symbolic root objects although the defining quartic can be       > factored rationally over the complex numbers.       >              roots still there              ....              > - non-elementary Timofeev 8.97.n (#632):       > integrate(log(log(x))^n/x, x) is expressible in functions covered by       > Risch extension, but returned unevaluated, which correctly identifies       > the integral as non-elementary though.       >              Now it returns this              ii:=integrate(log(log(x))^n/x, x);               cos(n*pi())*Gamma(n+1,(-1)*log(log(x)))                     > - ad-hoc parametrized nested algebraic:       > integrate(1/((p*sqrt(1 - x^2) - 1)*sqrt(p*sqrt(1 - x^2) - x^2)), x)       > fails to return unevaluated.       >              still does not evaluate, gives              ii:=integrate(1/((p*sqrt(1 - x^2) - 1)*sqrt(p*sqrt(1 - x^2) - x^2)), x);       >> Error detected within library code:        Denominator not equal to 1              > - ad-hoc elliptic: integrate((5*x - 9*sqrt(6) + 26)       > /((x^2 - 4*x - 50)*sqrt(x^3 - 30*x - 56)), x) fails to return       > unevaluated.       >              gives              ii:=integrate((5*x - 9*sqrt(6) + 26)/((x^2 - 4*x - 50)*sqrt(x^3 - 30*x - 56)),       x);               >> Error detected within library code:        catdef: division by zero              ...              > - infamous cube-root Goursat pseudo-elliptic:       > integrate((1 + x)/((1 + x + x^2)*(a + b*x^3)^(1/3)), x) fails to       > evaluate.       >              Yes, no response after 20 minutes...terminated.              > - 4th-root pseudo-elliptic:       > integrate((a + b*x)/((2 - x^2)*(x^2 - 1)^(1/4)), x) fails to evaluate.       >              seems to hang also, waiting about 10 mins.              > - pseudo-elliptic involving dependent nested roots of integers:       > integrate((7*x + 6*sqrt(17*sqrt(2) + 23) + 9*sqrt(2) + 34)       > /((x + 3*sqrt(2) + 4)*(x + 6*sqrt(sqrt(2) + 1) - 3*sqrt(2) - 2)       > *sqrt(x^3 - 30*x - 56)), x) fails to evaluate.       >              Same result.                     > Martin.              --- SoupGate-Win32 v1.05        * Origin: you cannot sedate... all the things you hate (1:229/2)    |
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