A Turing Machine example (Recognition of Palindromes) 
* from "The Design and Analysis of Computer Algorithms [1976]" 
* by A.V.Aho, J.E.Hopcroft, J.D.Ullman 
* --> See examples 1.8, 1.9 

The program contains no check points.

P.S. In this example an original Aho-Hopcroft-Ullman's program is partially changed.
