:- module rtree.
:- interface.
:- import_module list.
:- type box.
:- type box3d.
:- type interval.
:- type rtree(K, V).
:- typeclass region(K).
:- instance (rtree.region(rtree.box)).
:- instance (rtree.region(rtree.box3d)).
:- instance (rtree.region(rtree.interval)).
