Temporal, spatial, and spatio-temporal granularities allow one to qualify classical data locating them in time and space. In order to compare data qualified with different granularities and associate data to different granularities, it is necessary to know how the involved granularities are related. However, the explicit calculation of these relationships may be heavy from a computational point of view. Thus, in this paper, we propose an inference system for inferring definitely valid relationships starting from a set of already known valid relationships without to calculate them explicitly. We will prove the soundness and completeness of the system
