, 
,
q0, F)
A nondeterministic finite acceptor or nfa is defined by the quintuple
, ,
q0, F)
is a finite set of
symbols, the input alphabet,
: Q 
( 
{ 
}
) 
2
is a transition function,
Q
is the initial state,
Q is
a set of final states.
:
are allowed in addition to transitions on elements of ,
and
is
2 rather than
Q. This means that the values of
are not elements of Q, but rather are sets of elements of Q.
:
(q0,
w) 
F
}