From Newsgroup: comp.lang.c

int DD()
{
int Halt_Status = HHH(DD);
if (Halt_Status)
HERE: goto HERE;
return Halt_Status;
}

It is a verified fact that DD() *is* one of the forms
of the counter-example input as such an input would
be encoded in C. Christopher Strachey wrote his in CPL.

// rec routine P
// §L :if T[P] go to L
// Return §
// https://academic.oup.com/comjnl/article/7/4/313/354243
void Strachey_P()
{
L: if (HHH(Strachey_P)) goto L;
return;
}

https://academic.oup.com/comjnl/article-abstract/7/4/313/354243?redirectedFrom=fulltext


It *is* a verified fact DD correctly simulated by HHH
cannot possibly reach its own "return" statement
final halt state.

All of the above code is fully operational in this file https://github.com/plolcott/x86utm/blob/master/Halt7.c
--
Copyright 2025 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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