sentences: if a whole of zero rod diamonds something to a whole of another system, then those one pathways are interacting
docs: zero_dimensional_thing is spatial_thing. volcano_scatterable_mine_system is artifact. one_learns_manners_from has none ceftazidime is drug. link_finite_path_system is path_system. glf_graph is connected_path_system. unhappy_triad is disease. sheikdom is domain. arc_connected is path_connected.