Abstract:
We start with the assumption that temporal knowledge
usually captured by constraint networks
can be represented and queried more effectively by using
the scheme of indefinite constraint databases proposed by Koubarakis.
Although query evaluation
in this scheme is in general a hard computational problem,
we demonstrate that there are several interesting cases where
query evaluation can be done in PTIME. These tractability
results are original and subsume previous results
by van Beek, Brusoni, Console and Terenziani.
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