2 Let Incg be the geometrical inclusion of two objects. We assume the specifications of the geometrical intersection operator, Intg, are defined as: Incg (A, B) = A => Intg (A, B) = A.
3 One can remark that this distance is different from the distance of query C1.
4 To simplify the presentation, we do not take into account geometrical properties in the Where clause (e.g. minimum bounding rectangle), which can be defined as attributes or as an internal information of an abstract data type representation used by the geometrical operator.