/*
* This problem is intended to introduce some basic concepts about the constraint network and the available numeric constraints.
* Notice that this problem is inconsistent. An explanation for the inconsistency should be generated.
*/
// we create some real variable..
real x0;
real x1;
// we add some contraints..
x0 < x1;
x0 > 10;
x0 + x1 < 20; // this constraint makes the problem inconsistent..