typedef CGAL::Simple_cartesian<double> Kernel;

typedef Kernel::Point_2 Point_2;

int main()

{

{

Point_2 p(0, 0.3), q(1, 0.6), r(2, 0.9);

std::cout << (CGAL::collinear(p,q,r) ? "collinear\n" : "not collinear\n");

}

{

Point_2 p(0, 1.0/3.0), q(1, 2.0/3.0), r(2, 1);

std::cout << (CGAL::collinear(p,q,r) ? "collinear\n" : "not collinear\n");

}

{

Point_2 p(0,0), q(1, 1), r(2, 2);

std::cout << (CGAL::collinear(p,q,r) ? "collinear\n" : "not collinear\n");

}

return 0;

}