Question: invoking levin by default



> > How about this:  use "nsum" instead of "sum"  (Mathematica uses NSum vs
> > Sum).
> >   
> Yes this could be a good idea.
> > Or do this:
> >
> > Simpsum:Levin, as a third option, other than true and false.
> >   
> This I don't really like. Numerical evaluation is not the same as 
> simplification.

But in maxima those two things are strongly related. numer actually
is a simplifier flag:

(%i1) simp:false;
(%o1)                                false
(%i2) sin(1), numer;
(%o2)                               sin(1)
(%i3) sin(1), numer,simp;
(%o3)                          .8414709848078965

When I noticed this first, while playing with simplification vs. evaluation,
I was quite puzzled, but I think now I see why this actually is a job for
the simplifier. I guess somebody should write a book about maxima, which
handles such concepts in detail...

Regards,
Harald