A deterministic finite automaton (DFA)
is given by:
As an example consider the following automaton
The DFA may be more conveniently represented by a transition table:
Yet another, optically more inspiring, alternative are transition diagrams:
There is an arrow into the initial state and all final states are
marked by double rings. If
then there is an arrow
from state
to
which is labelled
.
We write for the set of words (i.e. sequences) over the
alphabet
. This includes the empty word which is written
. I.e.