Originating in Allen's analysis of temporal relations , the notion of a composition table (CT) has become a key technique in providing an ef-cient inference mechanism for a wide class of theories. Inâ€¦ (More)

In Tarskiâ€™s formalisation, the universe of a relation algebra (RA) consists of a set of binary relations. A first contribution of this work is the introduction of RAs whose universe is a set ofâ€¦ (More)

We propose a calculus, cCOA, combining, thus more expressive than each of, two orientation calculi well-known in QSR: Frankâ€™s projection-based cardinal direction calculus, CDA, and a coarser version,â€¦ (More)

The paper describes an algebraic framework for representing and reasoning about 2D spatial regions. The framework consists of a Closure Algebra (CA) of half-planes (Boolean Algebra augmented with theâ€¦ (More)

Combining different knowledge representation languages is one of the main topics in Qualitative Spatial Reasoning (QSR). Existing languages are generally incomparable in terms of expressive power; asâ€¦ (More)

The aim of this work is to provide a family of qualitative theories for spatial change in general, and for motion of spatial scenes in particular. Motion of an n-object spatial scene is seen as aâ€¦ (More)

We consider reasoning in an algebra of cyclic time intervals recently known in the literature; the algebra, CZ.A, is somehow the cyclic time counterpart of Allenâ€™s algebra of linear time intervals,â€¦ (More)