We can represent the hard-wired control device of a finite automaton by a directed multigraph:
- with the vertices representing the states
- arrow-edges being labelled by symbols of the input alphabet
- the initial state is marked by
- the favourable states are double-circled
- each arrow represents a possible transition, hard-wired in the control device: an arrow from state to state labelled by symbol indicates that, when the head is reading and the control device is in state then it should move next to state