[FOM] 2,3 Turing machine proof controversy

Alex Galicki alex.galicki at googlemail.com
Fri Nov 9 23:59:58 EST 2007

On 10/11/2007, Vaughan Pratt <pratt at cs.stanford.edu> wrote:
> I see two challenges here.  First, can you replace outside intervention
> by a single infinite initial condition that encodes at one time the
> infinitely many restarts your proof was performing manually, so that the
> subject 2,3 machine can do its own restarting?  And second, can you
> convince the appropriate audience (I hesitate to say "committee" or
> "Rules and Guidelines" since I no longer understand the meaning of those
> terms for this prize) that the notion of universality entailed by your
> infinite initial condition falls within the scope of what the prize
> envisages as "universal."

It would be useful to see any *real* definition of that notion. To
prove that "X in universal" one has either to use the standard
definition of universality or to introduce his own definition.
Clearly, the standard definition is not applicable in this case and so
far I failed to find (in the proof and here on POM) the non-standard
one. Or am I just blind?


More information about the FOM mailing list