As in the LINK classifier, we enforce global role constraints when creating training instances for the MOVELINK classifiers.
the roles assigned to the spatial elements in each training instance of each MOVELINK classifier are subject to six constraints: (1) the trigger has type motion event; (2) the mover has type place, path, spatial entity, or non-motion event; (3) the source, the goal, and the landmark can be NULL or have type place, path, spatial entity, or non-motion event; (4) the midpoint can be NULL or have type place, path, or spatial entity; (5) the path can be NULL or have type path; and (6) the motion signal can be NULL or have type motion signal.