This is too easy, so let's repeat it in symbols:

A Turing Machine T = (Q, ,
, ,
q_{0}, #, F) accepts a language L(M), where

for some q

(Notice that this definition assumes that the Turing machine starts with its tape head positioned on the leftmost symbol.)

We said a Turing machine accepts its input if it halts in a final state. There are two ways this could fail to happen:

- The Turing machine could halt in a nonfinal state, or
- The Turing machine could never stop
(in which case we say it is in an
*infinite loop.*)

Copyright © 1996 by David Matuszek

Last modified Mar 25, 1996