Re: [Axiom-developer] choose the better expand

[Francois Maltey]

Re-hello,

I find how to use retractIfCan(x)@Union(Integer, "failed"), 

But I can't detect if the basis ring R is a complex one :
real and imag work in any *.input files, but can't compile even
if I add :
  
  CTM ==> ComplexTrigonometricManipulations _
             (Integer, Expression Complex Integer)
  ...
  R is Complex Integer => 
    imag arg::Expression Complex Integer)@CTM
  ...

The type of the variable arg is F inside the manip.spad file, 
and I believe that << F = Expression Complex Integer >>
because << R is Complex Integer >> in this case.
But I can't coerce from F to Expression Complex Integer even if they are
equal.

The function imag is in ComplexTrigonometricManipulations...
I see it with )sh... but I can't use it in the *.spad file.

I continue to discover axiom...

Francois