Sujet : Re: Categorically exhaustive reasoning applied to the decision to abort
De : F.Zwarts (at) *nospam* HetNet.nl (Fred. Zwarts)
Groupes : comp.theoryDate : 27. Mar 2024, 11:55:25
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <uu0qee$2orpg$1@dont-email.me>
References : 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
User-Agent : Mozilla Thunderbird
Op 26.mrt.2024 om 15:43 schreef olcott:
On 3/26/2024 3:51 AM, Fred. Zwarts wrote:
Op 25.mrt.2024 om 23:50 schreef olcott:
On 3/24/2024 11:42 AM, Mikko wrote:
On 2024-03-24 03:39:12 +0000, olcott said:
>
On 3/23/2024 9:54 PM, immibis wrote:
On 24/03/24 03:40, olcott wrote:
On 3/23/2024 9:34 PM, immibis wrote:
On 24/03/24 03:15, olcott wrote:
On 3/23/2024 8:40 PM, immibis wrote:
On 24/03/24 00:29, olcott wrote:
On 3/23/2024 5:58 PM, immibis wrote:
On 23/03/24 16:02, olcott wrote:
(b) H(D,D) that DOES abort its simulation is correct
(ABOUT THIS ABORT DECISION)
because it would halt and all deciders must always halt.
>
To be a decider it has to give an answer.
>
To be a halt decider it has to give an answer that is the same as whether the direct execution of its input would halt.
>
That would entail that
>
Tough shit. That is the requirement.
>
I proved otherwise in the parts you erased.
>
You proved that the requirement is not actually the requirement?
>
I proved that it cannot be a coherent requirement, it can still
be an incoherent requirement. Try and think it through for yourself.
>
Every program/input pair either halts some time, or never halts.
Determining this is a coherent requirement.
>
That part is coherent.
>
The part that this determination must be done by a Turing machine
using descriptions of the program and input is coherent, too.
>
>
Every decider is required by definition to only report on what
this input specifies.
>
int sum(int x, int y){ return x + y; }
sum(3,4) is not allowed to report on the sum of 5 + 6
even if you really really believe that it should.
>
>
Exactly! Therefore H(D,D), where D is based on H that aborts and returns false, so that D halts, should not return a report about another D that does not halt, even if you really really believe that it should.
There is enough information for sum(3,4) to compute the sum of 3+4.
There is NOT enough information for sum(3,4) to compute the sum of 5+6.
There is enough information for H1(D,D) to compute Halts(D,D).
There is NOT enough information for H(D,D) to compute Halts(D,D).
But it is possible to create a simulating sum decider that aborts sum and returns the sum of 5+6 and then claim that it is right, because it has not enough information to calculate 3+4. It is possible, but wrong.
The only reason it has not enough information, is that it aborts prematurely. That makes the decision to abort wrong. This holds for H as well.
…