“…Other context dependencies are discussed, but not implemented into the model; in particular, the attractiveness of objects (e.g., 1 km from a shop may be far, but 1 km from a toxic waste dump very near) and reachability. Finally, [203] deals with the construction of fuzzy sets for concepts such as near and far, by asking the user a series of questions of the form Do you consider x to be far from y, which have to be answered by either yes or no (x and y are cities, and users are given a map to answer the questions). The goal is to allow for flexible querying in GIS systems, by using membership definitions of vague nearness relations that correspond to the interpretation of these concepts by the user.…”