“…In these cases, monotone sets are half-spaces that might be empty or, at an interior point (density point), might be the whole space; for the case of R n , see [22,23]; for the case of H, see [27]; see also [12,15]. In these cases, monotone sets are half-spaces that might be empty or, at an interior point (density point), might be the whole space; for the case of R n , see [22,23]; for the case of H, see [27]; see also [12,15].…”