Kernel::Has_on_positive_side_d

A model for this must provide:

template <class Kernel_object>
bool fo ( Kernel_object o , Kernel::Point_d p )
returns true iff p is on the positive side of o. Kernel_object may be any of Kernel::Sphere_d, Kernel::Hyperplane_d.
Precondition: p and o have the same dimension.