]> PERSON:Alan Ruttenberg Because OBI spans many levels of granularity, we can't effectively use the BFO three level granularity model. Thus we erase the difference using this strategy of saying it is any of the material like entities in BFO Material is any of bfo:Object, bfo:ObjectAggregate, or bfo:FiatObjectPart. material entity entity continuant independent_continuant definition editor editor note definition relates a class to a property where instances of the class make sense as subjects of the property relates a class to a property where instances of the class make sense as objects of the property relates a class to a property where some instances of the class may make sense as subjects of the property relates a class to a property where some instances of the class may make sense as objects of the property has_input is_input_of has_quality has_output is_manufactured_by has_function is_reagent_in utilizes_reagent is_output_of is_proxy_for has_role adjacent_to agent_in contained_in contains derived_into derives_from has_agent has_integral_part has_part has_participant has_proper_part integral_part_of located_in location_of part_of participates_in proper_part_of relationship transformation_of