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From: dbush <dbush.mobile@gmail.com>
Newsgroups: comp.theory
Subject: Re: How do computations actually work?
Date: Sat, 24 May 2025 12:37:02 -0400
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On 5/24/2025 12:06 PM, olcott wrote:
> On 5/24/2025 10:15 AM, dbush wrote:
>> On 5/24/2025 11:13 AM, olcott wrote:
>>> On 5/24/2025 2:39 AM, Mikko wrote:
>>>> On 2025-05-23 16:10:19 +0000, olcott said:
>>>>
>>>>> On 5/23/2025 2:14 AM, Mikko wrote:
>>>>>> On 2025-05-23 03:31:15 +0000, olcott said:
>>>>>>
>>>>>>> On 5/22/2025 10:23 PM, wij wrote:
>>>>>>>> On Thu, 2025-05-22 at 21:47 -0500, olcott wrote:
>>>>>>>>> [cut]
>>>>>>>>
>>>>>>>> Q: How do computations actually work?
>>>>>>>> A: Computation is merely step-by-step algorithm.
>>>>>>>> Nothing says it has to be TM.
>>>>>>>>
>>>>>>>> Do the exercises in textbooks first before any claim of it.
>>>>>>>>
>>>>>>>
>>>>>>> int main()
>>>>>>> {
>>>>>>>    DD(); // by what steps can the HHH that DD calls
>>>>>>> }       // report on the behavior its caller?
>>>>>>
>>>>>> If we don't insist that the report be correct:
>>>>>> 1. guess
>>>>>> 2. tell what was guessed
>>>>>
>>>>> This does not work because all computable functions
>>>>> that implement termination analyzers must compute
>>>>> the mapping from their input finite string according
>>>>> to the behavior that it specifies.
>>>>
>>>> Wrong. There is no need to compute "the" mapping if a the report
>>>> needs not be correct. Some other mapping is enough to produce
>>>> some report.
>>>>
>>>
>>> int sum(int x, int y) { return 5; }
>>> Does not compute any function because it ignores its inputs.
>>>
>>
>> Sure it does.  It computes this function:
>>
>>
>> For all integers X and Y:
>>
>> (X,Y) maps to 5
>>
>>
>> The only requirements for mapping is a function is that inputs 
>> correspond to outputs as per the given mapping, and the mathematical 
>> function above is mapped by the above C function "sum".
> 
> OK
> 
> int main()
> {
>    DD(); // How does the HHH that DD calls report on the
> }       // actual behavior of its actual caller?
> 

It doesn't matter, as your HHH doesn't accept a description of an 
algorithm as input and therefore has nothing to do with the halting 
problem, as you yourself have admitted:


On 5/13/2025 9:54 PM, dbush wrote:
 > On 5/13/2025 9:48 PM, olcott wrote:
 >> On 5/13/2025 8:31 PM, dbush wrote:
 >>> On 5/13/2025 9:27 PM, olcott wrote:
 >>>> On 5/13/2025 8:07 PM, dbush wrote:
 >>>>> On 5/13/2025 5:30 PM, olcott wrote:
 >>>>>> On 5/13/2025 6:43 AM, Richard Damon wrote:
 >>>>>>> On 5/13/25 12:52 AM, olcott wrote:
 >>>>>>>> *simulated D would never stop running unless aborted*
 >>>>>>>> or they themselves could become non-terminating.
 >>>>>>>
 >>>>>>> But you aren't simulating the same PROGRAM D that the original
 >>>>>>> was given.
 >>>>>>>
 >>>>>>
 >>>>>> It is not supposed to be the same program.
 >>>>>
 >>>>> So you *explicitly* admit to changing the input.
 >>>>>
 >>>>
 >>>> The finite string of DD is specific sequence bytes.
 >>>
 >>> Which includes the specific sequence of bytes that is the finite
 >>> string HHH
 >>>
 >>
 >> No it does not. A function calls is not macro inclusion.
 >>
 >
 > Then you admit that your HHH not deciding about algorithms and therefore
 > has nothing to do with the halting problem.