Additional comment: a computational agent can be considered as a PhysicalAgent that realizes a certain class of algorithms (that can be considered as instances of InformationObject) that allow to obtain some behaviors that are considered typical of agents in general. For an ontology of computational objects based on DOLCE see e.g. http://www.loa-cnr.it/COS/COS.owl, and http://www.loa-cnr.it/KCO/KCO.owl.