Re: Can an abort decider be defined that cannot be fooled by any pathological input?

On 3/25/24 11:17 AM, olcott wrote:

On 3/24/2024 3:51 AM, Fred. Zwarts wrote:

Op 24.mrt.2024 om 05:55 schreef olcott:

Can an abort decider be defined that cannot be fooled by any pathological input?
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01 int D(ptr x)  // ptr is pointer to int function
02 {
03   int Halt_Status = H(x, x);
04   if (Halt_Status)
05     HERE: goto HERE;
06   return Halt_Status;
07 }
08
09 void main()
10 {
11   H(D,D);
12 }
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Of all of the elements of the set of H(D,D) where H simulates its
input there are matched pairs of otherwise identical elements that
only differ by whether they abort their simulation or not.
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The half of these that don't abort are incorrect because all deciders
must halt. This makes the other half correct about the abort/no abort
decision.

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No. The other, aborting, half is just wrong, because it aborts when it is not needed. So, the half that aborts is wrong and it may be argued that it is better to not abort something that halts on its own and that

 At least two software engineers with masters degrees in computer science
disagree. Exactly what are you software engineering skills? I have been
a professional C++ software engineer since Y2K.

NEWBIE.
I've been paid to produce software since 1975. (and programming as a hobby before that)
I have also studied some Computation Theory and have pointed out the errors in those two "software engineers with master degrees in computar science" arguements based on DEFINITION in Computation Theory, that I suspect they never actually studied.

 

therefore not responding is better than responding with a wrong answer. So, both halves are wrong, but the half that aborts is more wrong. It gives the wrong answer. The other half is also wrong, but it does not give a wrong answer, but does not respond.
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I don't think an abort decider can be fooled by a pathological input.
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I am very sorry to hear that.
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