Action: Optimizing information.
Agent: An optimizing system where an internal representation of optimality causes system behavior.
Automaton: An optimizing system where no internal representations of optimality cause system behavior.
Controller: A system that maps States and Valences to Actions.
Environment: Everything that is external to a system.
Evaluator: A system that maps States to Valences.
Events: Changes in an Environment.
Model: A system that maps States to States.
Plant (Process-Actuator): A system that maps Actions to Events.
Sensor: A system that maps Events to States.
State: Representational information.
Valence: Optimality information.