The tape alphabet is {b, 0, 1, *}.

The set of states is {A}.

The instructions are:

(A, 0, A, 1, L)

(A, 1, A, 0, L)

The starting state is A and the tape is positioned so that its leftmost 0 or 1 is under the read/write head.

*10001*

When does it halt?

 

(A, 0, A, 1, L) (A, 1, A, 0, L)	Start							*	1	0	0	0	1	*
	State and position =>								A
	New Tape						*	0	0	0	0	1	*
	State and position =>								A
	New Tape					*	0	1	0	0	1	*
	State and position =>								A
	New Tape				*	0	1	1	0	1	*
	State and position =>								A
	New Tape			*	0	1	1	1	1	*
	State and position =>								A
	New Tape		*	0	1	1	1	0	*
	HALT!								A

  It would appear that this machine changes 1's to 0s and 0s to 1s everywhere. Check this out with other examples.