This class only implements the generation of Structured CSP problem.
In Structured CSP, variables are divided into several kernels (some variables
may remain ouside kernels). Different constraints (in density and tightnes)
are generated according to whether variables are from the same kernel or not.
This library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 3 of the
License, or (at your option) any later version.
This library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.