AbstractWe survey the use and effect of decomposition-based techniques in qualitative
spatial and temporal constraint-based reasoning, and clarify the notions of a
tree decomposition, a chordal graph, and a partitioning graph, and their
implication with a particular constraint property that has been extensively used
in the literature, namely, patchwork. As a consequence, we prove that a recently
proposed decomposition-based approach that was presented in the study by
Nikolaou and Koubarakis for checking the satisfiability of qualitative spatial
constraint networks lacks soundness. Therefore, the approach becomes quite
controversial as it does not seem to offer any technical advance at all, while
results of an experimental evaluation of it in a following work presented in the
study by Sioutis become questionable. Finally, we present a particular tree
decomposition that is based on the biconnected components of the constraint
graph of a given large network, and show that it allows for cost-free
utilization of parallelism for a qualitative constraint language that has
patchwork for satisfiable atomic networks.
Solving multi-granularity temporal constraint networks