#2467 Maxima aborts (radcan, simp=false)

open
nobody
5
2012-11-18
2012-09-08
Anton Voropaev
No

INPUT

build_info();
radcan((6^(log(12)/log(6))+1)^(1/2)), simp=false;

INPUT AND OUTPUT

(%i1) build_info();
(%o1)
Maxima version: "5.28.0-2"
Maxima build date: "2012-08-27 23:16:48"
Host type: "i686-pc-mingw32"
Lisp implementation type: "GNU Common Lisp (GCL)"
Lisp implementation version: "GCL 2.6.8"
(%i2) radcan((6^(log(12)/log(6))+1)^(1/2)), simp=false;
<ABORT>

Discussion

  • Raymond Toy
    Raymond Toy
    2012-10-06

    Why do you want simp=false? Almost nothing works with simp set to false.

     
  • Anton Voropaev
    Anton Voropaev
    2012-10-07

    Exactly, it is almost an "almost nothing" case.
    If there were no ^(1/2) then simp=false would be very beneficial:
    (%i1) radcan(6^(log(12)/log(6)));
    (%o1) %e^((log(3)^2+2*log(2)^2)/(log(3)+log(2)))*2^(3*log(3)/(log(3)+log(2)))
    (%i2) radcan(6^(log(12)/log(6))), simp=false;
    (%o2) 12

    Setting logsimp=false works around the problem:
    (%i3) radcan((6^(log(12)/log(6))+1)^(1/2)), logsimp=false;
    (%o3) %e^(log(%e^(log(3)+2*log(2))+1)/2)
    Thereafter, one needs to call radcan repeatedly:
    (%i4) radcan(%);
    (%o4) sqrt(13)

    Anyway, I think that specifying simp=false should not cause a fatal error.