A Topological Calculus for Cartographic Entities

Qualitative spatial reasoning (QSR) has many and varied applications among which reasoning about cartographic entities. We focus on reasoning about topological relations for which two approaches can be found in the literature: region-based approaches, for which the basic spatial entity is the spatial region; and point-set approaches, for which spatial regions are viewed as sets of points. We will follow the latter approach and provide a calculus for reasoning about point-like, linear and areal entities in geographic maps. The calculus consists of a constraint-based approach to the calculus-based method (CBM) in (Clementini et al., 1993). It is presented as an algebra alike to Allen's (1983) temporal interval algebra. One advantage of presenting the CBM calculus in this way is that Allen's incremental constraint propagation algorithm can then be used to reason about knowledge expressed in the calculus. The algorithm is guided by composition tables and a converse table provided in this contribution.