1. Of physical and chemical in nature: Cleaning, vulcanizing, fluxing, indicator, sterilizing, emulisifying, refining. 2. Organisms: animals, cells, parts of organisms (organs, organelles, viruses).

Agent(x) ↔ (Person(x) ∨ GroupOfAgents(x) ∨ EngineeredSystem(x)) ∧ ∃r(AgentRole(r) ∧ hasRole(x,r))

every instance of 'agent' is defined as exactly an instance of 'person', 'group of agents', or 'engineered system' when it 'has role' some 'agent role'

1. See the expanded definition under the corresponding role class. The term is formalized here as a defined class by referring to its corresponding role class and exists primarily for ontological modeling and implementation convenience. 2. The IOF has elected to exclude material substances often referred to as agents. That is, they realize some specific function that some person desires (e.g., platinum is a reducing agent in various reduction-type reactions -- as used in a catalytic converter to eliminate or reduce various pollutants in exhausts). 3. The IOF has, at this time, excluded non-human agents, such as animals and other organisms (often referred to as biological agents).

Agent(x) ↔ (Person(x) ∨ GroupOfAgents(x) ∨ EngineeredSystem(x)) ∧ ∃r(AgentRole(r) ∧ hasRole(x,r))

iof-core:Agent

Agent

every instance of 'agent' is defined as exactly an instance of 'person', 'group of agents', or 'engineered system' when it 'has role' some 'agent role'