XPost: comp.theory, sci.logic, sci.math
On 11/18/2021 7:00 AM, Mr Flibble wrote:
On Thu, 18 Nov 2021 06:29:26 -0500
Richard Damon <[email protected]> wrote:
On 11/17/21 10:48 PM, olcott wrote:
For every possible H of H(P,P) invoked from main() where P(P) calls
this same H(P,P) and H simulates or executes its input and aborts
or does not abort its input P never reaches its last instruction.
computation that halts
a computation is said to halt whenever it enters a final state.
(Linz:1990:234)
No, you LIE.
Halting is DEFINED by the behavior of the actual computation.
H(P,P) is supposed to say what P(P) will do.
No,
H(P,I) is supposed to say what P(H(P(H(P(H(P(...
i.e. it is infinite recursion due to a category error; H(P,I) as
defined is INVALID. The halting problem as defined is INVALID.
/Flibble
I made the "impossible" inputs decidable.
int H(ptr x, ptr y)
{
x(y); // direct execution of P(P)
return 1;
}
// Minimal essence of Linz(1990) Ĥ
// and Strachey(1965) P
int P(ptr x)
{
H(x, x);
return 1; // Give P a last instruction at the "c" level
}
int main(void)
{
H(P, P);
}
(1) H(P,P) simply executes its input:
main() calls H(P,P) that calls P(P) that calls H(P,P)...
(2) H(P,P) simulates its input.
(3) H(P,P) executes its input** and aborts this execution at some point.
**(a debugger could be used).
(4) H(P,P) simulates its input and aborts this simulation at some point.
For every possible H of H(P,P) invoked from main() where P(P) calls this
same H(P,P) and H simulates or executes its input and aborts or does not
abort its input P never reaches its last instruction.
The above defines all of the combinations of H/P having pathological self-reference.
Cases (3) and (4) define the subset of these where the behavior of
H(P,P) diverges for the behavior of P(P).
--
Copyright 2021 Pete Olcott
Talent hits a target no one else can hit;
Genius hits a target no one else can see.
Arthur Schopenhauer
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