A system comprising at least a first, a second and a third element, and a motion module (10, 90), said elements being three-dimensional and each element comprising: - a centre point in said element; - at least one face coupled to said centre point and said face comprising: - a motion-guiding module (11, 14, 15, 20), defining a trajectory over at least part of said face; - a motion-restriction module (11, 14, 15, 30), adapted for limiting the displacement of said centre point with respect to said centre point of one of the other elements to at least one trajectory selected from the group consisting of said trajectory and said trajectory of said other element, when interacting with said motion module; wherein said motion module (10, 90) is adapted to be coupled to a face of one of said elements, and adapted for displacing said centre point of said one element with respect to said centre point of one of the other elements when interacting with the motion-guiding module of said one of the other elements, said motion-guiding module, said motion module and said motion-restriction module defining different module types, wherein for displacing said centre point of said first element away from said centre point of said second element and towards said centre point of said third element, a first face of said at least one face of said first element faces at least one of a second face of said at least one face of said second element and a third face of said at least one face of said third element, thus providing facing faces, wherein for said displacing: - said motion module interacts with at least one motion-guiding module, and with at least one motion-restriction module, with said facing faces providing said interacting modules while displacing; - at least one module of said first face interacts with at least one module of at least one different module type of at least one other of said facing faces while displacing, and - said at least one module of said first face interacts with at least one module of a different module type of said second face and at least one module of a different module type of said third face, characterized in that said motion module is adapted for decoupling from said face of said one of said elements and for moving from one face to another when decoupled from said face. - a centre point in said element; - at least one face coupled to said centre point and said face comprising: - a motion-guiding module (11, 14, 15, 20), defining a trajectory over at least part of said face; - a motion-restriction module (11, 14, 15, 30), adapted for limiting the displacement of said centre point with respect to said centre point of one of the other elements to at least one trajectory selected from the group consisting of said trajectory and said trajectory of said other element, when interacting with said motion module; - a motion-guiding module (11, 14, 15, 20), defining a trajectory over at least part of said face; - a motion-restriction module (11, 14, 15, 30), adapted for limiting the displacement of said centre point with respect to said centre point of one of the other elements to at least one trajectory selected from the group consisting of said trajectory and said trajectory of said other element, when interacting with said motion module; - said motion module interacts with at least one motion-guiding module, and with at least one motion-restriction module, with said facing faces providing said interacting modules while displacing; - at least one module of said first face interacts with at least one module of at least one different module type of at least one other of said facing faces while displacing, and - said at least one module of said first face interacts with at least one module of a different module type of said second face and at least one module of a different module type of said third face, characterized in that said motion module is adapted for decoupling from said face of said one of said elements and for moving from one face to another when decoupled from said face.