“…These constraints are usually expressed through a domain of application (DoA) -i.e., the region of space where the constraint must be met-, and a restriction in the aircraft state -i.e., the condition that must be met, usually related to speed or altitude. DoAs may be restricted to simple geometrical shapes [26] or arbitrary shapes [37]. Sometimes, DoAs are defined by elements of the airspace structure, such as legs, routes, significant points, or 3D volumes.…”