I guess that the starting state of the tape is generally not considered to be part of the Turing machine itself; so the set of Turing machines of n-states is still computable. Although, if your Turing machine is a universal Turing machine, the way you get it to emulate another Turing machine is to pass it in via an encoding on the tape, so the idea of pre-writing the tape is certainly valid, it's just not part of a particular Turing machine's definition.
On Tue, Jul 23, 2013 at 4:58 PM, Levi Pearson <[email protected]> wrote: > > The problem with enumerating Turing Machines is the tape. You can't, > in general, enumerate all Turing machines of n states because they > include a finite tape that can hold an arbitrarily large finite number > of non-blank cells. Of course, the BB problem specifically states an > all-blank tape; I think this makes potential-BB Turing machines > enumerable. Just enumerate all the possible 5-tuples with the {0, 1} > alphabet and n states, and there you go. > > --Levi /* PLUG: http://plug.org, #utah on irc.freenode.net Unsubscribe: http://plug.org/mailman/options/plug Don't fear the penguin. */
