Re: Unpartial Halt Deciders

Keith Thompson <Keith.S.Thompson+u@gmail.com> wrote:

[ .... ]

Another point: The well known proof that the Halting Problem is
not solvable works by assuming that a halt decider exists and then
creating *one* input, based on the code of the decider, on which
the decider cannot give a correct answer.  You can call that input
"self-referential to the decider".

A small point: I think it is less confusing to say that an example input
program which the purported halt decider fails on is *selected* from the
countably infinite set of programs, rather than created.

[ .... ]

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */

--
Alan Mackenzie (Nuremberg, Germany).