[PPL-devel] PPL and simplification of polyhedra

[Sven Verdoolaege]

On Mon, Aug 18, 2008 at 05:17:01PM +0200, Roberto Bagnara wrote:
> Albert Cohen wrote:
> >The concept is called "gist" in Omega, and simplification under a
> >context in PolyLib. You'd like to run the simplification with the
> >assumption that some constraints are already enforced, and only retain
> >the additional constraints (minimized) to define a given sub-polyhedron.
> 
> Hi Albert,
> 
> we need to have a more precise specification of the required operation.
> In particular, for the simplification of  { A <= 0 } under the context

I assume you mean { A = 0 } here (as { A <= 0 } is not a subset of {A >= 0}).

> { A >= 0 }, what do you consider simpler?
> 
> Possibility 1:  { A <= 0 }
> Possibility 2:  { A = 0 }.

I asked the same question on the polylib mailing list many
years ago but got no answer.

skimo