a dispersal point is a mean of preposition
time_point_preposition is temporal_preposition. locative_preposition is spatial_preposition. directional_preposition is not spatial_preposition. temporal_preposition is preposition. spatial_preposition is preposition. time_point_preposition is not temporal_preposition. accumulation_point is limit_point. atelic_directional_preposition is spatial_preposition. directional_preposition is spatial_preposition.