final-state function y: from S
*
to Q such
that y(w) is the state in which M ends up
after scanning the string w.
Thus, M accepts w if and only if y(w) A.
For example, y(abbaa)=0, and y(bbabaaa)=1.
• y(e) = q0
, (* empty string does not change
any current state *)
• y(wa) = d(y(w),a) for w S
*
, a S.