-----maxima-bounces at math.utexas.edu wrote: -----
>If abs or arg cannot be simplified without asking questions, just leave it
be.
For the experimental to_poly + to_poly solver, I had so much trouble
with cabs, carg, and conditionals, I wrote my own. I know, that's terrible,
but
I was having too many problems testing my code. Here parg is my version
of carg and xif my version of if:
(%i3) load("topoly.lisp")$
(%i5) sol : xsolve(sqrt(x)=a,x);
(%o5) xif(2*parg(a)+%pi>0 and (2*parg(a)-%pi=0 or -(2*parg(a)-%pi)>
0),[x=a^2])
(%i6) subst(a=1+%i,sol);
(%o6) [x=(%i+1)^2],
(%i7) subst(a=-1+%i,sol);
(%o7) emptyset
If I commit this version of to_poly, I'll need expunge these private
functions,
find workarounds or fix the bugs in the standard code.
In short, bugs in sign, abs, carg, .... makes it difficult to do cool
stuff.
Barton