has participant http://purl.obolibrary.org/obo/ro.owl Has_participant is a primitive instance-level relation between a process, a continuant, and a time at which the continuant participates in some way in the process. The relation obtains, for example, when this particular process of oxygen exchange across this particular alveolar membrane has_participant this particular sample of hemoglobin at this particular time. a relation between a process and a continuant, in which the continuant is somehow involved in the process has participant http://www.obofoundry.org/ro/#OBO_REL:has_participant has_participant this blood coagulation has participant this blood clot this investigation has participant this investigator this process has participant this input material (or this output material)