 Interval-based models usually presuppose linear time. Still, they are ontologically richer than instant-based models, as there are many more possible relationships between time intervals than between time instants. An interval-based model of time can, for instance, include the relations temporal precedence \(\prec,\) inclusion \(\sqsubseteq,\) and overlap \(O\) over a set of time intervals \(T\): formally, \(\mathcal{T}= \left\langle T,\prec,\sqsubseteq, O \right\rangle.\) Some natural properties of such interval-based relations and models include: 