Re: the Halting Problem

[http://dummy.us.eu.org/robert (Robert)]

The Wikipedia article describes the proof at
https://en.wikipedia.org/wiki/Halting_problem#Proof_concept .

Actually, the description of the rigorous proof is quite elegant -- better
than I remember when I was in school.  For example, I didn't realize that
there was an analogy to Cantor's countability diagonal argument.

There's also a much smaller description of the proof at
https://cs.stackexchange.com/a/42830 , which, I presume, is the one that
we had to come up with in the Theory of Computation class.

There's also an interesting argument about its proof-by-construction at
https://www.reddit.com/r/math/comments/t8bnje/to_what_extent_do_non_constructive_existence/ .
I think the consensus there is that it is impossible.  But, then again,
maybe this will change after it's been proven that P = NP ð???.