Wishlist (relational, pseries, matrix)

[Pearu Peterson]

Hi!

I have been working with GiNaC's interface to Python for some time now and
I have collected the following notes that I have found important in this
kind of applications:

1) Having relational::get_operator() would be useful (read: necessary) for
   extensions that can perform symbolic operations like
   (a < b) && (b > a)    ->    a < b

2) If a,b are compatible pseries then
      ex(a) * ex(b)
   would automatically produce
      ex(a.mul_series(b))
   The same for operations +,-,scalar_mul,scalar_div.
   If a,b are incompatible, then apply current
   behaviour (that is, do nothing).

   I have implemented this behaviour in the GiNaC->Python interface but
   it does not cover cases where multiplication is carried out inside
   GiNaC functions. I am thinking of applications where, for example, 
   a matrix consists of compatible pseries and the task is to find its
   inverse.

3) If a,b are compatible matrices (for a given operation) then
     ex(a) * ex(b)   ->  ex(a.mul(b))
   The same for operations +,-,scalar_mul,scalar_div.

That's all for now. 
Regards,
	Pearu