  We introduce a new tractable temporal constraint language, which strictly
contains the Ord-Horn language of Buerkert and Nebel and the class of AND/OR
precedence constraints. The algorithm we present for this language decides
whether a given set of constraints is consistent in time that is quadratic in
the input size. We also prove that (unlike Ord-Horn) this language cannot be
solved by Datalog or by establishing local consistency.
