# Talk:205: Candy Button Paper

Revision as of 16:03, 6 July 2013 by 69.163.36.90 (talk)

It is possible to run a Turing machine on a candy belt:

Marvin Minsky (1967), Computation: Finite and Infinite Machines, Prentice-Hall, Inc. Englewood Cliffs, N.J. In particular see p. 262ff (italics in original):
"We can now demonstrate the remarkable fact, first shown by Wang [1957], that for any Turing machine T there is an equivalent Turing machine TN that *never changes a once-written symbol*! In fact, we will construct a two-symbol machine TN that can only change blank squares on its tape to 1's but can not change a 1 back to a blank." Minsky then offers a proof of this. 69.163.36.90 16:01, 6 July 2013 (UTC)