http://en.wikipedia.org/wiki/Accessory_(legal_term) http://www.ontologyrepository.com/CommonCoreOntologies/Mid/ExtendedRelationOntology has accessory x has_accessory y iff x is an instance of Process and y is an instance of Agent, such that y assists another agent in the commission of x, and y was not located at the location of x when x occurred, and y was not an agent_in x.