Four definitions as a contribution to the third synthesis in control

Definitions of some key concepts (model, intelligence, learning, control) are proposed as a contribution to unify the different paradigms and cultures actually existent in systems and control. These definitions are made in the information space, an extension of the state space with the additional dimension of information granularity. The aim is to create a common language and a common framework where all cultures of control can meet and work together for the progress of the science and technology in order to maintain Control as a leading discipline.