Re: Suggested method for returning a string from a C program?

On 2025-03-20, Muttley@DastardlyHQ.org <Muttley@DastardlyHQ.org> wrote:

On Thu, 20 Mar 2025 16:14:54 -0000 (UTC)
Kaz Kylheku <643-408-1753@kylheku.com> wibbled:

On 2025-03-20, Muttley@DastardlyHQ.org <Muttley@DastardlyHQ.org> wrote:

I guess some maths problems can't be proven directly, they have to be - for
want of a better word - run. A bit like the halting problem in CS.

>
The halting problem is a perfect example of a problem which *cannot* be
proven by running anything.

>
So if you run the program and it halts that doesn't prove that it will halt?
Umm, ok.

If you run a program and it has NOT halted so far, you don't know
whether or not it halts. If it doesn't halt, you will wait forever. To
figure that out, you have to resort to proof techniques, not just more
waiting.

Determining whether one program halts or not is not even the Halting
Problem. The Halting Problem consists of the question: is there an
algorithm which can decide, for any <P, I> (program, input) pairs from
the universe of all possible programs and inputs, whether P(I) halts.

The accepted result is that, no, there is no such decision algorithm.
In short, the halting question is called undecidable.

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