[PPL-devel] integer versus rational solutions

[Albert Cohen]

Roberto Bagnara wrote:
> Tobias Grosser wrote:
>> Sure. I understand that the number of dimensions and/or (in)equalities
>> is a limitation. What I do not understand is why the values in an
>> (in)equality are problematic. This is why
>> 1 > i might be easier to handle than 99999999 > i
> 
> Concerning the PPL, the operations performed on coefficients are mostly
> additions/subtractions, multiplications, GCDs and exact divisions.
> Addition/subtraction is linear in the number of bits,
> multiplication and division are (roughly) quadratic,
> GCD is sub-quadratic since GMP 4.3.0.
> 
> Nothing prevents an application of the PPL to build constraints
> with coefficients with millions of digits.  Personally, I never
> saw that phenomenon but, as I say, this depends on the application.
> Cheers,

I never saw this either.

But Tobias is right: I did not answer his question... What was missing 
is that, in the case of FM, those much-appreciated degenerate cases 
where 0 or 1 inequality is inserted tend to exist only in "well-behaved" 
situations with small coefficients (i.e.... degenerate).

Albert