A hierarchy for convex relations

This paper is concerned with a hierarchical representation of the convex relation algebra, which is a computationally tractable subset of Allen´s interval calculus. The hierarchy of convex relations is used to determine the minimal point relation constraints which hold between the end points of the intervals. Nine convex relations are proven to be special, because they introduce new constraints. One intended application of this hierarchy is a natural language discourse processing system. A more precise specification for the temporal constraints derivable by the discourse grammar due to Lascarides and Asher (1993) is given