Sujet : Re: I call it a halting decidability decider
De : mikko.levanto (at) *nospam* iki.fi (Mikko)
Groupes : comp.theoryDate : 07. Aug 2024, 09:04:14
Autres entêtes
Organisation : -
Message-ID : <v8v69e$29dq4$1@dont-email.me>
References : 1 2 3
User-Agent : Unison/2.2
On 2024-08-05 11:50:53 +0000, olcott said:
On 8/5/2024 3:08 AM, Mikko wrote:
On 2024-08-04 14:46:02 +0000, olcott said:
When we define an input that does the opposite of whatever
value that its halt decider reports there is a way for the
halt decider to report correctly.
int DD()
{
int Halt_Status = HHH(DD);
if (Halt_Status)
HERE: goto HERE;
return Halt_Status;
}
int main()
{
HHH(DD);
}
HHH returns false indicating that it cannot
correctly determine that its input halts.
True would mean that its input halts.
That is called a "partial halt decider". The set of requirements is
a subset of the requirements for "halt decider" but still require
that the answer is not "halts" if the input does not halt and that
the answer is not "does not halt" if the input halts. The difference
is that a "halt decider" is required to give one of these answers
for every input but a "partial halt decider" is not.
For every computation there is a partial halt decider that answers it.
I call it a halting decidability decider.
1=input halts
0=input does not halt or has pathological relationship with its decider
There is no "its decider". The identity of the decider is not a property
of the input.
-- Mikko