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 to pological relations for which two approaches can be found in the literature : region-based approaches, for which the basic spatial entity is the spatia l 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 map s. The calculus consists of a constraint-based approach to the calculus-bas ed method (CBM) in (Clementini ct al., 1993). It is presented as an algebra alike to Alien's (1983) temporal interval algebra. One advantage of presen ting the CBM calculus in this way is that Alien's incremental constraint pr opagation 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.