Abstract: An element having a holding mechanism, adapted for interacting with a functionally aligned holding mechanism of a similar element, and including a holding state and a released state. The holding mechanism in the holding state is engaged with the aligned holding mechanism of the similar element for holding the element positioned with respect to the similar element. The holding element in the released state is disengaged with the aligned holding mechanism. The element also includes a sensing mechanism for providing grab-detection, the grab-detection including detection of an action leading to a grip of the element, having a grip on the element, an action of releasing a grip of the element, and a combination thereof. The sensing mechanism is functionally coupled to the holding mechanism for upon the grab-detection actuating at least one of the functionally aligned holding mechanism between the holding state and the released state.

Abstract: A system having at least a first, a second and a third three-dimensional element, each element including a centre point in the element, and a face with a motion-guiding module, coupled to the centre point and defining a trajectory over the element, a motion module, adapted for displacing the centre point with respect to a second centre point of one of the other elements using the motion-guiding module of that other element, a motion-restriction module, adapted for limiting the displacement of the centre point with respect to the second centre point to at least one trajectory selected from the group which includes the trajectory and a second trajectory of the other element.

Abstract: An element having a holding mechanism, adapted for interacting with a functionally aligned holding mechanism of a similar element, and including a holding state and a released state. The holding mechanism in the holding state is engaged with the aligned holding mechanism of the similar element for holding the element positioned with respect to the similar element. The holding element in the released state is disengaged with the aligned holding mechanism. The element also includes a sensing mechanism for providing grab-detection, the grab-detection including detection of an action leading to a grip of the element, having a grip on the element, an action of releasing a grip of the element, and a combination thereof. The sensing mechanism is functionally coupled to the holding mechanism for upon the grab-detection actuating at least one of the functionally aligned holding mechanism between the holding state and the released state.