Interval containment order
= Interval containment order
{title2=$[l,u]\preceq[l',u']\iff l'\leq l\land u\leq u'$}
The <partial order> on nonempty closed <integer intervals> given by <subset> inclusion. The <least upper bound> of two such <intervals> is their interval hull $[\min(l,l'),\max(u,u')]$. The hull can contain points absent from both original <intervals>, so it need not equal their <union>.