Motivation: Defining Behavior The operational principle of a concept explains its archetypal behavior: how it’s typically used, and how it fulfills its purpose. But for a concept to be flexible and powerful, it should work in many different scenarios, so we need a way to pin down the behavior in detail. Using the notion of a state machine, we can define how a concept will behave in every possible situation. Then we can analyze the design to make sure that the behavior is always acceptable.