Re: [Axiom-developer] Axiom Design Question / Polymake feedback

[William Sit]

I am jumping in here, so excuse me if comments are out of context.

"Page, Bill" wrote:
> 
> I think there are two possible bug reports here:
> 
> 1) Union ( list of alternatives that are coercible to some ring )
>    should be a RING

No! In your case, where the arguments of the union form an ascending chain of
rings, that would be true. In general, you cannot do arithmetic with operands
from different rings. Think about Union(INT, MATRIX INT).

The best one can do in Martin's case would be, as you noted,

   Union(MATRIX INT, MATRIX FRAC INT, MATRIX FLOAT)

To use List List Union(INT, FRAC INT, FLOAT) would require one to do case
statements in every entry of the matrix and also lose the ring properties of
matrices.
 
> 2) display of TwoDimensionalArray of type Union(...) is not properly
>    formatted

Seems like a bug.

William