couple of questions about complex expressions

On Tue, Sep 25, 2012 at 4:38 AM, Barton Willis <willisb at unk.edu> wrote:

> The user documentation for the (obscurely named) option variable m1bpranch
> is clear enough, but a user doesn't know when a (-1)^power is  going to be
> generated.

I guess I would be happy enough if m1pbranch applied to any negative
real number, but then the name doesn't match ...

> I think that domain : larry and m1pbranch : sally gives the principal branch
> too:

I suppose if we look at the code it says something like
(if (not (eq '$domain '$real)) ...) and (if $m1pbranch ...).

I guess attempts to assign such values could be prevented by
a custom assignment function. There is already machinery in place
for that.

Thanks for your help,

Robert Dodier

PS. Seems like domain:complex is enough to get the result
I was looking for:

(%i2) domain : complex $
(%i3) integrate (exp (x^3), x, 1, 2);
(%o3) ((-1)^(2/3)*gamma_incomplete(1/3,-8)-(-1)^(2/3)
                                           *gamma_incomplete(1/3,-1))/3
(%i4) %, numer, expand;
(%o4) 275.5109837633115-7.71234927772942E-14*%i