[PPL-devel] integer versus rational solutions

[Konrad Trifunovic]

Hi,

that's a good point.
We DO NOT need NNC polyhedra. Closed Polyhedra are fine
(at least for dependence analysis). Do You think that using
C_Polyhedron would help us avoid the much of the complexity problems?

from my analysis (by looking at the PPL code) I have seen
that the "contains_integer_point" methods call the MIP
(Mixed Integer Programming) routines, to solve the system of constraints.
I have seen that it behaves differently in the case of Convex and
NNC polyhedra.

regards,
Konrad

2009/7/9 Roberto Bagnara <bagnara at cs.unipr.it>:
>
> Konrad Trifunovic wrote:
>> I attach a patch that uses 'integer existence test'.
>> I have forced the use of dependence check.
>
> Hi there.
>
> I am sorry if the answer is obvious, but I am wondering
> why you are using NNC polyhedra (NNC_Polyhedron) instead
> of ordinary polyhedra (C_Polyhedron).  Do you need to
> characterize rational solutions and use strict constraints?
> All the best,
>
>     Roberto
>
> --
> Prof. Roberto Bagnara
> Computer Science Group
> Department of Mathematics, University of Parma, Italy
> http://www.cs.unipr.it/~bagnara/
> mailto:bagnara at cs.unipr.it
>
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