A finite automaton is characterized by the following properties:
- an initial state
- a finite set of possible internal states
- a next-state function allowing for transitions from one internal state some other one
- a subset of the set of internal states, whose elements are selectors of inputs (accepting states)
An elemental automaton is open to any acceptable input and must necessarily function as a sequential machine. It can be represented by a graph. (After F. HARARY and S. LIPSCHUTZ, 1967)
However, according to J.von NEUMANN, as quoted by L. LÖFGREN: "… when an automaton is not very complicated, the description of the functions of that automaton is simpler than a description on the automaton itself but … the situation is reversed with respect to complicated automata" (1977, p.211)
This is a result of the simultaneous interplay of various rules, which leads to ergodicity or chaos.