Dear Pat,
Thank you for the prompt response!
Yes, the coefficients of constraints and generators have to be integers (mpz_class in the default configuration). However, the PPL implements a domain of convex _rational_ polyhedra. The restriction to integer coefficients is just for the representation and input/output. We can do this since any constraint having rational coefficients can be normalized so as to have integer coefficients. For generators, the same is achieved by including an integer divisor, (which by default is 1, but not necessarily so).
Thank you for pointing this out - I missed the presence of integer divisors. With the divisors, the library completely serves our needs.
I see from your email that you already have written your own algorithms for intersection and convex-hull. These as well as union are operations provided by the PPL. Documentation for these is in the PPL; but if you miss the exact information needed to make full use of the PPL, you should not hesitate to ask.
Apologies, I was unclear: in fact I should have said we have algorithms that *make use* of intersection, convex-hull, etc. These algorithms are exactly the reason why I am interested in using the PPL.
Best wishes
Alet