Re: The simple essence of Proof Theoretic Semantics

On 7/4/2026 9:32 AM, olcott wrote:
> On 7/4/2026 2:37 AM, Mikko wrote:
>> On 2026-07-02 dbush wrote:
>>
>>> The halting problem doesn't actually have self reference, as
>>  > algorithms can be copied as in the below example of algorithm D:
>>>
>>> void D(ptr *I)
>>> {
>>>      // algorithm D; input: I
>>>      ptr *X = D;
>>>      ptr *Y = I;
>>>      int result;
>>>      {
>>>          // algorithm H; inputs: X,Y
>>>          result = 0;
>>>      }
>>>      if (result == 1) {
>>>          while (1);
>>>      }
>>> }
>>>
>>> Which is the counter example input to algorithm H:
>>>
>>> int H(ptr *X, ptr *Y)
>>> {
>>>      int result;
>>>      {
>>>          // algorithm H; inputs: X,Y
>>>          result = 0;
>>>      }
>>>      return result;
>>> }
>>
>> On 03/07/2026 18:36, olcott wrote:
>>> On 7/3/2026 4:22 AM, Mikko wrote:
>>>> On 02/07/2026 17:51, olcott wrote:
>>>>>
>>>>> Do you know enough about C to understand that
>>>>> dbush example was foolish nonsense when proposed
>>>>> to show the halting problem counter-example?
>>>>
>>>> It is a valid example of a C program. It was present as a part of a
>>>> claim about you, and your response was the false claim that "That
>>>> is just nonsense". Later in the discussion you offer more evidence
>>>> to support his claim.
>>>
>>> His halt decider did not look at its input.
>>
>> For every possible input his H halts and returns either 0 for false
>> or 1 for true. Therefore his H is a decider. It return 0 for D
>> although D halts so the decider H is not a halt decider.
>>
> 
> counter-factual H always returns 0.

Which means the condition "either 0 or 1" is satisfied.

It seems we need to add "or" to the list of basic high school level 
logic topics you don't understand.

> 
>>> His input merely halted and did not call
>>> this halt decider. He used {} in a way that
>>> made no sense in C.
>>
>> His use of {} is perfectly correct by C rules and as meaningful ans
>> usually. Your false claim (not shown above) is false.
>>
> 
>