Abstract: The invention relates to a base station (100) provided with a processor and with bodies (1,3). Each body is provided at several outer surfaces thereof with visualisations such that a combination of visualisations can be formed in at least one plane by means of a number of outer surfaces of different bodies. At least a means is furthermore present in each body for enabling the processor to ascertain the position and orientation of each body used in a particular combination. The base station is further provided with a visualisation means (7,9) on which at least a portion of an assignment is printed, which visualisation means is provided with at least a communication means to the processor for communicating to the processor the possible answers to the assignment. The carrying out of the at least one assignment through the formation of an answer by means of the outer surfaces of the bodies with a combination of visualisations in at least one predetermined plane can be checked by the processor.

Abstract: A system of bodies each having their own electronic identity representation visualized on respective corresponding outer faces of these bodies. The bodies comprise communication means for having the identity representations queried externally. The system comprises means for selectively detecting respective predetermined physical concatenations of such identities as representations of corresponding visualizations and subsequently emitting an external signal, but refraining from producing such a signal in the absence of any such predetermined concatenation. The bodies are particularly suitable for mutual and wireless communication with their physical neighbors in said concatenation, to which end each body is provided with active electronic logic means and an associated electric battery power supply. Communication between the bodies takes place democratically and without the interposition of a master module.